Nira i7x Handbook

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NIRA i7x

Handbook

NIRA i7x Handbook version pA7, August 2016

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This handbook is protected by copyright laws. It may not be redistributed in any form without written consent of Nira Control AB.

Release 2016-08-30

The purpose of this handbook is to serve as a guide during installation and calibration of NIRA i7x. Descriptions, content and specifications in this handbook may be changed at any time. This handbook could contain errors – therefore it should not be regarded as a definitive installation guide. Nira Control AB is not responsible for any personal or property damages due to errors in this handbook, the professional installing NIRA i7x is responsible for the installation.

Misuse of NIRA i7x and/or NIRA rk can cause severe personal injury and engine damage. Nira Control AB is not responsible for any injuries, accidents or damages due to misuse or ignorance.

Repairs of NIRA i7x, e.g. replacement of parts, will affect the safety of the product and are not allowed under any circumstances. Nira Control AB is not responsible for any problems, accidents etc, caused by non-approved parts or repairs not carried out by Nira Control AB.

NIRA i7x must be installed by professional automotive technicians in accordance with the instructions in this handbook, following good practice.

NIRA i7x is only intended for racing use and not for use on public roads. It is not certified for use on vehicles subject to emission standards unless the appropriate waivers have been issued. Please check with the relevant authorities for more information.

NIRA rk is protected by applicable software copyright laws. You may not distribute this software without the written consent of Nira Control AB. You may not copy this software. Your purchase of NIRA i7x includes a single license to use NIRA rk together with NIRA i7x.

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1 Overview ................................................................................................... 5

1.1 Content of your NIRA i7x Package .................................................... 5

1.2 Glossary ............................................................................................. 6

1.3 NIRA i7x Functionality ..................................................................... 11

2 Combustion, Lambda and Measurement Principles .................................. 14

2.1 Relationship Between A/F and Lambda .......................................... 14

2.2 The Effect of Different Lambda Values ............................................ 15

2.3 Measurement Principles .................................................................. 16

2.4 Fuel delivery .................................................................................... 19

3 Installing NIRA i7x .................................................................................... 22

3.1 Crank Position Sensor (CKP) and Trigger Wheel ............................. 22

3.2 Cam Position Sensor (CMP) ............................................................. 26

3.3 Throttle Position Sensor (TPS) ......................................................... 27

3.4 Manifold Absolute Pressure (MAP) and Intake Air Temp (MAT) ...... 28

3.5 Boost pressure sensor (pre throttle pressure sensor) ....................... 29

3.6 Engine Coolant Temperature Sensor (ECT) ..................................... 29

3.7 Manifold Air Temperature Sensor (MAT) ......................................... 30

3.8 Lambda Sensor ................................................................................ 30

3.9 Exhaust Gas Temperature. .............................................................. 32

3.10 Anti Lag System (ALS) Switch .......................................................... 32

3.11 Launch Control Button .................................................................... 32

3.12 Aux Inputs ....................................................................................... 33

3.13 Ignition ............................................................................................ 33

3.14 Fuel Pressure Regulator (FPR) .......................................................... 34

3.15 Fuel Injectors .................................................................................. 34

3.16 Boost Pressure Actuator .................................................................. 35

3.17 IAC (Idle Air Control) ....................................................................... 37

3.18 Main Relay ....................................................................................... 39

3.19 Fuel Pump Relay .............................................................................. 39

3.20 Tachometer ..................................................................................... 40

3.21 ALS Solenoid ................................................................................... 40

3.22 Wheel Speed Sensors ...................................................................... 40

3.23 Aux Outputs .................................................................................... 41

3.24 Mounting NIRA i7x in the Car .......................................................... 41

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4 NIRA rk Software...................................................................................... 43

4.1 Installation of NIRA rk ...................................................................... 43

4.2 Getting Started ................................................................................ 44

4.3 Using NIRA rk .................................................................................. 47

4.4 Parameters ....................................................................................... 49

4.5 PID Controllers ................................................................................ 60

4.6 Gauges ............................................................................................ 62

4.7 Logging ........................................................................................... 65

4.8 Locking the i3d Data Set ................................................................. 68

4.9 FlexiPorts™ - Set up ........................................................................ 68

4.10 Auto Fuel Calibration ...................................................................... 70

4.11 Ignition/Fuel Mapping ..................................................................... 70

5 Starting the Engine .................................................................................. 70

5.1 Setting Up Parameters Offline ......................................................... 70

5.2 Going Online ................................................................................... 93

5.3 Quick Troubleshooting Guide ......................................................... 97

5.4 Other Adjustments .......................................................................... 98

6 Mapping your Engine Using NIRA rk ........................................................ 99

6.1 Tables .............................................................................................. 99

6.2 Calibrating Ignition .......................................................................... 99

6.3 Calibrating Fuel ............................................................................. 100

6.4 The Engine Runs Unevenly or Stalls .............................................. 108

6.5 Adjusting the Boost Pressure Control............................................ 109

6.6 IAC – Idle Speed Control............................................................... 109

6.7 ALS – response system .................................................................. 110

6.8 Launch Control .............................................................................. 111

6.9 Flat Shift ........................................................................................ 111

6.10 Traction Control............................................................................. 113

7 Electrical Specifications .......................................................................... 117

7.1 Input .............................................................................................. 117

7.2 Output ........................................................................................... 120

7.3 Communication ............................................................................. 122

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Overview

NIRA i7x is a sophisticated electronic engine management system developed specifically for racing. NIRA i7x controls ignition, fuel injection, idle speed, boost pressure and several other engine functions. It can be used with many different types of engines.

1.1 Content of your NIRA i7x Package

When you purchased NIRA i7x, you should have received the following:

 NIRA i7x  Wiring harness  NIRA rk calibration software  Communication interface (Kvaser CAN-dongle)

1.1.1 NIRA i7x

NIRA i7x is a highly sophisticated, triple core microprocessor based engine management system designed for motorsport applications. It controls ignition, fuel injection, boost pressure, idle speed and several other engine functions. NIRA i7x offers an unusual level of flexibility in how input signals are interpreted and processed. It also gives you significant control over the mapping of the output signals. This allows NIRA i7x to work with many different sensors, actuators and engine types. Setup, configuration and programming of NIRA i7x is done via the NIRA rk software.

1.1.2 Wiring Harness

One end of the wiring harness is pre crimped with NIRA i7x terminals. The terminals are easy to connect to the right position in the NIRA i7x connector. The other end of the harness is a set of pigtails used for connecting power, ground, sensors and actuators. To simplify the work of installing the harness,

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each wire in the harness is marked every 70 mm (~3”) with its function in

clear text. This makes it possible to cut the wire to desired length and still read its function.

1.1.3 NIRA rk

NIRA rk is the calibration software that allows you to setup and configure a large number of parameters in NIRA i7x. It is designed to run on a PC using the Windows operating system and communicates with NIRA i7x via a Kvase CAN-dongle.

The many functions of NIRA rk are described in detail starting in chapter 4.

NIRA rk is protected by applicable software copyright laws. You may not distribute this software without the express written consent of Nira Control AB. You may not copy this software other than for personal use. Your purchase of NIRA i7x includes a single license to use NIRA rk together with NIRA i7x.

1.1.4 Communication interface

The Kvaser CAN-dongle connects NIRA i7x to the PC running NIRA rk software. The CAN-dongle connects to your PC via a USB port.

1.2 Glossary

Absolute pressure

Absolute pressure is measured starting at 0 kPa. This is the pressure in vacuum. At sea-level the absolute pressure is approximately 100 kPa, +/- 10 kPa depending on the weather (high or low pressure.)

Alpha-N

Methodology to compute the amount of fuel to inject based only on rpm and throttle angle. Sometimes referred to as “throttle mapped.”

This mapping approach can be difficult to use and requires a high resolution throttle position sensor potentiometer.

On engines with aggressive camshaft profiles, the pressure in the intake manifold fluctuates

significantly. In such cases it’s not possible to get a

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stable MAP reading and throttle mapping is the only workable approach.

ALS

Anti Lag System. Sometimes called “response system.” Often used in racing and rally cars with

turbo engines. ALS maintains the boost pressure even though the throttle is closed. With ALS engaged, combustion in the exhaust manifold is common.

Ambient pressure

The pressure around us; approx 90 – 110 kPa absolute pressure depending on the weather (low or high pressure.) The pressure decreases with altitude.

Csd

Crankshaft degrees. A four-stroke engine turns 720 crankshaft degrees during one complete combustion cycle. (The camshaft turns half as fast as the crankshaft and thus completes 360 degrees during the four strokes.)

Default values

These are base values or recommended values.

EGTC

Exhaust Gas Temperature Control. Nira-developed exhaust gas temperature measurement unit. Can be connected to NIRA i7x.

GND

Ground (kl31)

Grounding can be done to the body, engine block or directly to the battery. Ground is sometimes referred to as minus or 0 Volt. Poor ground connections can cause problems that are hard to find. Make sure the ground connections are proper.

MAP

Manifold Absolute Pressure. Pressure in the intake manifold after the throttle plate. On a naturally aspirated engine this varies between 25kPa and 100kPa.

MAT

Intake Air Temperature or Manifold Air Temperature. Refers to the temperature of the air in the intake manifold. The temperature can be as much as 150 degrees hotter than the ambient air temperature on a turbo charged engine.

The density of the air decreases with increasing

temperature. Therefore it’s important to be able to

measure the temperature accurately in order to determine the engine load.

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Premature detonation (knock)

The flame front in the combustion chamber advances at around 1 000 m/s instead of the normal 100 m/s due to detonation instead of controlled combustion.

Knocking results in very high local combustion temperatures and damaging local detonations.

Pull-up resistor

A pull-up resistor connects an input or an output to +12 V (or +5 V). It pulls up the voltage on the input or output to +12 V (or +5 V).

Pull-down resistor

A pull-down resistor connects an input or an output to ground (0V). It pulls down the voltage on the input or output to ground level (0V).

Sequential injection

Each injector on/off is timed independently of all other injectors.

By taking camshaft timing into account, the engine can be made to run more smoothly and efficiently and to provide more low-end torque.

Speed-density

A simple and straightforward method for calculating the correct amount of fuel to inject based on MAP, MAT and the engine speed. Because MAP is used, any changes in ambient pressure are accounted for.

Terminal 15 (kl 15)

Terminal 15 is a term used to describe battery voltage (+12 V) after the ignition switch. Most sensors and actuators used with NIRA i7x that require battery voltage should be connected to terminal 15.

Terminal 30 (kl 30)

Terminal 30 is a term used to describe battery voltage (+12 V)

Terminal 31 (kl 31)

Se Ground

Throttle

The throttle is controlled by the gas pedal and determines the amount of air entering the intake manifold.

(Volumetric Efficiency)

A V.E. value of 1.0 means that 100% of the cylinder volume gets filled during the intake stroke. For example, if the cylinder volume is 500 cc, the engine breathes in exactly 500 cc of air.

Do not confuse V.E. with engine efficiency. A V.E.

value above 1.0 means there’s some amount of

supercharging due to resonance, which is unusual. If, during calibration, the V.E. table has values above 1.1, or the lambda table is not in line with

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actual (measured) lambda, you may have made a mistake.

Many standard engines have an average V.E. of

0.85.

60-2 lost

Common pattern on the crankshaft trig wheel. The trig wheel has 58 tooth-window pairs, spaced 6 degrees apart. Two tooth-window pairs are missing (“2-lost”) and the resulting wider window serves as the reference point.

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1.2.1 NIRA Rk Naming

Abbreviation

Meaning

Description

Als

Anti Lag System

Air Mass

App

Accelerator Pedal Position

Bac

Boost Actuator Control

This is used if a boost actuator is used with position feedback

Boost Control

Normally used in Motorsport if not an advanced boost control is used (for example VGT with position feedback)

Base Variable

Variables to show the user data. For example Engine Coolant temperature

Dge

Diagnostic

Digital Input

Digital Output

Engine State

Esc

Engine Speed Control

Etm

Electronic Throttle Module

Fuel Mass

Ign

Ignition

Lmc

Lambda Module Control

Tpu

Time Process Unit

Processor that read values from time critical sensors (for example crank sensor)

Vehicle

Example traction control variables (TC).

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1.3 NIRA i7x Functionality

NIRA i7x reads sensor values, processes the data and sends output signals to various actuators.

NIRA i7x is a fully sequential engine management system for engines with up to 8 cylinders.

By using the NIRA rk software, you have the ability to modify many of the parameters that control the data processing and the output signals in NIRA i7x.

Picture 1-1: Overview of NIRA i7x inputs and outputs.

Picture 1-1 above shows the input signals and the output controls of NIRA i7x. Section 1.3.1 below lists all sensors used by NIRA i7x. Section 1.3.2 lists additional input controls used by NIRA i7x and section 1.3.3 lists output functions.

1.3.1 Sensors

 MAP sensor (Manifold Absolute Pressure)  Boost sensor (Pre throttle pressure measurement)  MAT sensor (Manifold Air Temperature)  CKP sensor (Crankshaft Position) Inductive or Hall  TPS (Throttle Position Sensor, measures the throttle butterfly angle)  CMP sensor (Cam Position. The crankshaft rotates two revolutions per

four strokes in a four-stroke engine. The camshaft rotates half as fast as the crankshaft so it completes one revolution per four strokes. The

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CMP sensor is used to determine in which of the two crank revolutions the engine is. This is used during cranking.) Inductive or Hall

 ECT (Engine Coolant Temp)  Fuel Temperature (for display purpose)  Fuel Pressure  Oil Pressure  Lambda sensor (NIRA i7x Street controls Bosch LSU 4.9 lambda

sensor without external electronics)

 EGTC (Exhaust Gas Temperature. Measures the exhaust gas

temperature in the exhaust manifold where the headers collect. NIRA i7x handles either digital egtc reading, resistive reading or 0-5V analog input)

 Flat Shift Switch  11 Aux inputs ( 3 Analog inputs, 6 Resistive temp sensors, 2 Digital

inputs)

1.3.2 Input Controls (driver controlled)

 Switch for Anti Lag System (ALS, response system)  Button for Launch Control

1.3.3 Output Functions

NIRA i7x processes the input signals and controls the output signals in order to manage the following actuators.

 8 Fuel injectors (amount and sequence)  8 Ignition coils (timing and dwell time). NIRA i7x controls active coils

(with integrated drivers) or passive coils that are connected to NIRA i7x via an external ignition driver

 Boost pressure control valve (controls boost pressure H bridge or

PWM output)

 IAC (Idle Air Control; controls engine idle speed via ignition

compensation and an IAC valve or motor)

 Fuel pump relay  Main relay (for actuator power supply)  Fan relay (for controlling radiator fan)  Tachometer output (engine speed)

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 ALS solenoid (for additional bypass air)  4 Aux outputs ( Auxiliary relay control and 3 PWM outputs)  Electronic throttle actuator

In addition to standard engine management, NIRA i7x includes a set of additional engine control strategies and functions. These are listed in section

1.3.4 and are described in detail later in this manual.

1.3.4 Additional Control Strategies/Functions

 Launch Control – enables fast take-offs with stable, pre-programmed

torque values

 Anti Lag System (ALS) – maintains boost pressure during shifts and

when letting off on the gas

 Flat Shift – reduces engine torque to enable quick gear shifts  FlexiPorts™ - a very advanced function that controls fuel injection,

ignition, boost pressure and Launch Control in relation to input axes configured during calibration

 Acceleration Fuel Enrichment –advanced fuel enrichment during

acceleration

 Cranking Fuel Enrichment – allows precision control of fuel injection

during cranking based on parameters such as ambient temp, time since last cranking attempt etc

 Alarms – adjustable alarm thresholds reduce the risk of engine

damage

 Limp home – any input sensor value out of range is replaced with a

reasonable value to keep the engine running, albeit at reduced power. Sets error code

 Diagnostics – read error codes  Logging – advanced data logging and graphical analysis tools in NIRA

rk software

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Combustion, Lambda and

Measurement Principles

For combustion to take place, oxygen needs to be available. The oxygen content of the air changes with air temperature and pressure. In an engine there are different ways of measuring the amount of air entering the engine, but regardless of the technique used, some way of converting the measurements into an absolute air mass is needed.

Once the air mass has been calculated, it’s possible to meter the amount of

fuel needed. The optimal air to fuel ratio, as measured in weight, depends on the type of fuel.

For instance, 1 gram of standard gasoline should be mixed with 14.6 grams of air to achieve complete combustion. This air/fuel ratio is known as the stoichiometric ratio and is also referred to as lambda 1.0. A richer mixture (more fuel) results in lambda < 1.0. A leaner mixture results in lambda > 1.0.

Lambda is central to the calibration of NIRA i7x and it’s important to understand what it represents and how it’s used.

2.1 Relationship Between A/F and Lambda

A/F means Air-Fuel ratio. It’s always given as a ratio of masses. The stoichiometric A/F is different for different types of fuel.

Example of stoichiometric A/F ratios:

Air/98 Octane Gasoline = 14.6

Air/Methanol = 6.8

Air/Ethanol = 9.0

Air/E85 = 11

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Lambda is defined as:

λ = (actual air fuel ratio)/(stoichiometeric ratio)

The definition of lambda is the same regardless of fuel type, which is advantageous, especially when switching between fuels.

Example of lambda calculation (using gasoline):

If an engine is running lean, the actual A/F may be 15.4:1.

λ = 15.4/14.6 = 1.05

If an engine is running rich, the actual A/F may be 14.0:1.

λ = 14.0/14.6 = 0.96

Some wide-band lambda sensors use A/F in their specs, so it is important to understand the relationship between A/F and lambda.

2.2 The Effect of Different Lambda Values

If lambda is far from 1.0, the air-fuel mixture can’t be ignited. This causes engine misfires. The point at which these occur depends on several different parameters, such as the temperature in the combustion chamber, the efficiency of the ignition system and how well mixed the air and fuel are. Typically, lambda has to stay within the 0.7 – 1.2 range.

If the air and fuel haven’t mixed fully before ignition, some amount of fuel will be wasted. This is common, especially during transients and at low rpm’s. Consequently, most engines run better when the mixture is a bit richer than lambda 1.0. A good rule of thumb is 5-7% richer, or lambda 0.95-0.93.

Adding even more fuel usually lowers engine efficiency at a given intake air pressure but it also cools the combustion chamber. This is exploited in turbo charged engines where the boost pressure can be increased somewhat while avoiding premature detonation, or engine knock.

The end result is that by running a turbo engine extra rich, you can gain more power. On a normally tuned turbo engine, it’s common to adjust lambda down towards 0.84. On an aggressively tuned engine, lambda may have to go even lower if there are problems with the exhaust gas temperature being too high.

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2.3 Measurement Principles

All engine management systems have to determine engine position and calculate the correct mass of fuel to inject for a given mass of air. The masses of the fuel and air vary with temperature and pressure.

2.3.1 Angular positioning

The engine angular position of the crank shaft is crucial for accurate engine control.

The most common types of sensors used for angular positioning in automotive applications are

 Hall sensor  Inductive sensor

Hall sensor

The Hall Effect is based on a magnetic field that affects electrons moving in a conductor. The sensor is in need of power supply and the output is a square wave with fixed voltage levels. The output level is equal or less the supply voltage.

Example of CKP & CMP hall sensors plotted over one revolution. “CKP is a 24-1 pattern”

Inductive sensor

The inductive sensor or VR sensor (Variable Reluctance) uses the phenomenon of induced voltage in the sensor. The voltage is induced when ferrite steel passes the sensor and changes the flux through the sensor’s built in magnet. Therefore the sensor is not in need of any power supply. The output voltage from the sensor will go from negative to positive values. The output levels from the sensor will increase proportionally to the speed of the tooth passing the sensor.

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Example of an inductive CKP sensor signal when a ”2 lost” is detected from a pulse wheel

with a ”60 – 2 lost” pattern

Zero crossing detection and crank polarity

When using an inductive sensor the system uses zero crossing detection to determine the position of the crankshaft.

Examlpe of zero crossing detection for falling & rising edge.

The picture above shows two types of zero crossing.

 The red circle shows zero crossing at the transition from high level to

low level, falling edge

 The blue circle shows zero crossing at the transition from low level to

high level, rising edge. In the “lost gap” the zero crossing is widely spread and can’t be uniquely defined

By swapping the polarity of the inductive sensor the signal will be inverted. NIRA i7x uses zero crossing detection at falling edge, which means the scope

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picture has to look like the pictures above. The level transition through the “2 lost”-gap cannot be falling in this case.

Example of wrong polarity at inductive sensor. The level transition through the gap is falling

and the zero crossing will be undefined in the blue circled area.

2.3.2 Volumetric Efficiency (VE)

For controlling the air mass flow through the engine, a volumetric efficiency model can be used. The VE model uses Manifold Air Pressure or Throttle Position sensor together with Engine Speed to choose a VE value. The VE value is volumetric fill rate of the displacement and calculated for every stroke. A VE value of 1 means that 100 % of the cylinder is filled with air during intake stroke. For example, if the cylinder volume is 500 cc, the engine breathes in exactly 500 cc of air while the intake valve is open.

VE to Fuel Mass

With the density of air, the volume can be converted to air mass filled into the cylinder every stroke. Based on the air mass filled into the cylinder it is possible to calculate fuel mass based on the desired A/F-ratio.

Volumetric Efficiency and Boost Pressure

The Volumetric Efficiency does not have to increase with increased boost pressure. The intake air mass will increase and thus, the volume filled into the cylinder contains compressed air. If high exhaust manifold pressure occurs, the VE might even decrease.

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2.3.3 Mass Airflow Sensors (MAF)

Most modern engines have MAF sensors. These essentially weigh the incoming air before it enters the engine. The engine control system receives information about how many grams of air/millisecond have passed through the MAF sensor.

Using a MAF has a major advantage in that it reports only the amount of air that actually enters the engine. Engine wear during a long life is factored in automatically using this approach. Additionally, MAF sensors simplify the fuel calibration significantly. This was especially important many years ago when the computational power of the microprocessor in the engine management system was limited.

Today, MAF is the standard because of strict emission standards that apply during the entire life of the engine. There are, however, several disadvantages:

 MAF sensors are slow to react, expensive and sensitive to damage.

There are often problems using MAF sensors on aggressively tuned engines because the sensor can break due to high airflow

 The sensor itself is mounted in a housing, which represents a

restriction to the intake air

 There are also problems with oil entering the intake tract from the

turbo due to the restriction

2.3.4 Alfa-N and Speed-Density

During the mid-1990’s many cars used speed-density systems. Speed-density systems have no restrictions in the intake tract (as compared to MAF sensor systems) and the precision was good enough over the lifetime of the engine to meet the emission rules of the time.

On low cost vehicles, Alfa-N systems were common. Alfa-N systems are very inexpensive to manufacture because they only require a high-precision TPS. Unfortunately, as the engine wears, the TPS value no longer is a correct measure of how much air the engine takes in and this leads to emissions related problems

NIRA i7x has the capability to control fuel injection (and ignition) based on speed-density, Alfa-N -- or a combination of the two.

2.4 Fuel delivery

See the example picture below over a fuel delivery system.

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Fuel Rail

Fuel Pump

FPR

Fuel Tank

Manifold

Air

Pressure

Low fuel pressure

High fuel pressure

Low fuel pressure. Back flow

Manifold Air Pressure

Overview of fuel delivery system

 Fuel Pump: The purpose is to pump fuel from the tank or catch tank

and pressurize the fuel rail

 Fuel Rail: The hardware connection that feed the injectors with

pressurized fuel

 FPR (Fuel Pressure Regulator): FPR controls the fuel pressure by

controlling backflow. The FPR is often adjustable to set the base pressure. A hose from the manifold is connected to the FPR with purpose to increase or decrease the fuel pressure when manifold air pressure changes. The most common is to increase the pressure in a linear relationship

 Injector: Injectors supply the engine with fuel by injecting fuel in the

inlet port. The injectors are electrically controlled by NIRA i7x.

2.4.1 Why use a Fuel Pressure Regulator with MAP Feedback

As described above, the fuel pressure is increased with raised manifold air pressure. The reason for this is to keep the same pressure balance over the injector.

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When testing an injector fuel flow rate in a test rig, the fuel pressure is fixed (~3bar = 400 kPa absolute) and the injectors injects into atmospheric pressure (~100 kPa absolute). That means that the pressure balance over the injector is 400-100 = 300 kPa. The injector flow rate for these conditions is entered in to ECU for fuel mass calculation.

Injectors mounted at an engine will inject the fuel into the air pressure of the manifold. If a fixed fuel pressure is used, the pressure balance over the injector will vary with manifold air pressure. This causes the ECU miscalculate the fuel mass to be injected.

By using a linear fuel pressure regulator with MAP feedback, the fuel pressure will increase 1 bar if the manifold air pressure increases 1 bar. This way, the pressure balance over the injector will remain the same.

If a nonlinear fuel pressure regulator is used, a compensation has to be entered into the ECU to make the fuel calculations correct.

P1 = 3 bar (4 bar abs)

P2 = 0 bar (~1 bar abs)

ΔP= 3 – 0 = 3 bar

P1 = 3 bar (4 bar abs)

P2 = 1 bar (~2 bar abs)

ΔP= 3 – 1 = 2 bar

Test conditions for characterization

Running conditions 1 bar boost pressure (P2)

Without Fuel Pressure Regulator

P1 = 4 bar (5 bar abs)

P2 = 1 bar (~2 bar abs)

ΔP= 4 – 1 = 3 bar

Running conditions 1 bar boost pressure (P2)

With Fuel Pressure Regulator

Picture of injector pressure balance variation due to manifold air pressure and fuel pressure

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Installing NIRA i7x

When installing NIRA i7x it is recommended that you follow the directions below. Begin by determining if additional sensors are needed and where to install them. Make sure any existing sensors you expect to use with NIRA i7x are in good working order. The NIRA i7x wiring harness has markings in clear text on each wire to simplify the work of connecting all the sensors.

Each sensor and actuator will need an appropriate connector attached to the harness. The connector terminals should be crimped for best performance and rubber seals should be used where the wires enter the connector housing. (Your NIRA i7x dealer sells seals for all sensors.) If proper crimp tools are not available, soldering may be used. Poorly crimped terminals are a common source of intermittent problems. Always cover any soldered splices with heat shrinkable tubing.

Do not skimp on the sensors. Use new sensors if you are unsure of the condition of the existing ones. Old throttle position sensors often have hardto-find drop out points which can not be detected with standard multimeters. Your NIRA i7x dealer stocks many of the sensors needed or can recommend sensors.

Note that the MAP, MAT and ECT sensors sold by your NIRA i7x dealer have been pre-calibrated in NIRA rk. These are recommended. Other sensors will need to be calibrated separately. Calibration is done using one of the Wizards in NIRA rk.

3.1 Crank Position Sensor (CKP) and Trigger

Wheel

To control ignition timing, injection timing and several other important outputs, NIRA i7x needs a signal that is telling the position of the crankshaft. This signal is provided by a crank position sensor that creates the signal by reading the pattern of a pulse wheel that is fitted to the crankshaft. NIRA i7x supports both hall sensors and inductive sensors.

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In the wiring harness there’s a shielded wire marked “Crank” with to wires

and one shield. The same wire should be used for both hall sensors and inductive sensors. Note the different sensor types are differently connected in the NIRA i7x connector.

Connection of Crank sensor

Type

Sensor Pin

Nira i7x pin

Wire

Hall sensor 5v Supply

E.95

Wire 1

Signal

E.72

Wire 2

Ground

E.92

Shield

Inductive

Signal +

E.93

Wire 1

Signal -

E.94

Wire 2

Shields

N.92

Shield

An accurate signal from the crank position sensor is crucial. Therefore, it is very important to install the CKP sensor with diligence. A faulty installation or a bad combination of CKP sensor and pulse wheel causes an unreliable signal. In turn, an unreliable signal will make the engine run poorly.

It’s important that the sensor mounting bracket is solid and that the trig wheel is 100 % aligned with the crankshaft.

Example of an inductive CKP sensor signal when a ”2 lost” is detected from a pulse wheel

with a ”60 – 2 lost” pattern.

The signal from the CKP sensor should resemble the pattern in the image above. It is recommended to use an oscilloscope to study the signal.

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Definition of a Trig and Maximum Voltage

Trig

Occurs when a falling pulse flank passes zero

Min voltage

0,4 V between peak and ground at 100 rpm. 2,5 V at 6 000 rpm

Max voltage

300 V peak to peak

3.1.1 The Pulse Wheel

NIRA i7x works with the majority of standard pulse wheels

that has one or two pulses “removed” as a reference point. On engines

where such a pulse wheel is factory fitted it is recommended to keep the factory installation. The picture above and right is showing a pulse wheel of the type “60 – 2 lost” that is a standard pulse pattern. This pulse wheel has 58 teeth and a gap that is created by the removal of 2 teeth in the otherwise

symmetrical pattern. Hence the name “60 – 2 lost”. NIRA i7x is designed to handle pulse wheels of the types “60 – 2 lost”, “60 – 1 lost”, “ and symmetrical pulse wheels down to “16 – 2 lost” and “16 – 1 lost”.

Symmetrical pulse wheels have teeth that are equally distributed around the pulse wheel with the exception of a reference point where one or two teeth are missing. The table below describes the pulse wheels that are compatible with NIRA i7x.

Pulse Wheels Compatible with NIRA i7x

No of teeth, including ”missing teeth”

Pattern no 1 (1 tooth removed)

Pattern no 2 (2 teeth removed)

60 (each tooth + gap is 6°)

60 – 1 lost

60 – 2 lost

59 – 1 lost

59 – 2 lost

… … …

17 – 1 lost

17 – 2 lost

16 – 1 lost

16 – 2 lost

NIRA i7x reads symmetrical pulse wheels that are split into a maximum of 60 sections (60 – 1

lost, 60 – 2 lost) and a minimum of 16 sections (16 – 1 lost, 16 – 2 lost). All symmetrical

patterns in between are compatible with NIRA i7x.

As shown in the table above, NIRA i7x handles the most common types of

factory fitted pulse wheels, such as “60 – 2 lost” found on European cars (Volvo, Saab, Audi, BMW, Mercedes, etc), Ford’s “36 – 1 lost” and “24 – 1 lost” found on many motorcycle engines. There must not be any doubts

regarding what type of pulse wheel that is fitted on the engine. The pattern

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must be entered into NIRA rk and it is absolutely necessary to enter the correct values to be able to start the engine.

Some types of pulse wheels are made with holes drilled in a solid material. These pulse wheels often have a reference point in the shape of a peak instead of a valley – see the image below for sketch of a “60 – 1 lost” hole with a peak as a reference point.

Pulse wheel with a ”60 – 1 lost” pattern and a peak instead of a valley as reference point.

Pulse wheels having a peak instead of a valley or a hole as a reference point are more error prone since vibrations can cause false trigs when the reference point passes the sensor. If you are fitting a new pulse wheel when installing NIRA i7x, always choose a pulse wheel with a valley as reference point.

The trigger wheel mounts on the face of the crank pulley. If the crank pulley

is also a harmonic balancer, verify that it is in good condition and isn’t

slipping. Make sure the trig wheel is aligned on the pulley. If it is not centered properly, the signal strength from the CKP sensor will vary and ignition timing will drift back and forth.

The example below is given for fitting a “60 – 2 lost” pulse wheel: When figuring out the angular placement of the trigger wheel, first turn the engine to TDC for cylinder 1. Then place the trigger wheel such that the angle between the “2-lost” window and the place where you plan on mounting the CKP sensor is around 90-120 degrees. See picture 3-1 below. You will later need to measure the exact angle, see section 3.1.2.

Once the trigger wheel has been fitted, mount the CKP sensor. The gap between the CKP sensor and the trigger wheel should be 0.5-1.0mm. If the gap is greater than 1.0 mm, the signal strength from the CKP sensor will vary too much and timing will drift back and forth. Mount the sensor in a bracket that allows for slight adjustments. Secure the CKP sensor wires with cable ties to make sure they don’t interfere with e.g. engine drive belts.

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3.1.2 Measuring the ”2-lost” Angle

Turn the engine so that cylinder 1 is at TDC. Measure the angle between the center of the CKP and the trailing edge of the 2-lost (or 1 lost) window. See picture 3-1. Each tooth on the trigger wheel is 3 degrees and each window is 3 degrees. Make a note of the angle, as you will need to enter it into NIRA rk later.

Picture 3-1. Measuring the TDC to ”2-lost” angle.

3.2 Cam Position Sensor (CMP)

Since the fuel injection and ignition is controlled sequentially with NIRA i7x, a signal that tells NIRA i7x the engine’s phase in the combustion cycle is necessary. NIRA i7x thus requires that the engine has a Cam Position Sensor. This signal is used to synchronize the fuel injection and ignition with opening and closing of the intake valves during start. Your NIRA i7x dealer will advise you on an appropriate CMP sensor. Both hall sensors and inductive sensors are compatible with NIRA i7x.

In the wiring harness there’s a shielded wire marked “CAM” with two wires and one shield. The same wire should be used for both hall sensor and inductive sensor. Note that different sensor types connect differently in the NIRA i7x connector.

Connection of CAM sensor

Type

Sensor Pin

Nira i7x pin

Wire

Hall sensor 5v Supply

E.74

Wire 1

Signal

E.73

Wire 2

Ground

E.71

Shield

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Inductive

Signal +

E.73

Wire 1

Signal -

E.71

Wire 2

Shields

TBD

Shield

In order to create a well-defined trig point for the CMP sensor, drill and tap a hole in the cam gear. Insert a screw into the hole such that the screw head faces the sensor. The sensor works best if the screw material is magnetic, such as galvanized steel. The distance between the screw and the sensor may need to be adjusted in order for the sensor output voltage to be high enough. The output voltage from the CMP sensor needs to be at least 3V. Do not place the trig point in a place that gives a CMP signal at the same time that the reference point of the crankshaft pulse wheel passes the CKP sensor.

Sometimes it’s possible to use one of the camshaft lobes as a trigger.

3.3 Throttle Position Sensor (TPS)

The TPS needs to be of a linear potentiometer type. A worn TPS can cause problems which are very difficult to diagnose. Typically, as the TPS ages, the signal drops out intermittently. Either verify that your existing TPS is in excellent working order or simply replace it with a new one. Your NIRA i7x dealer stocks a suitable TPS.

If your car doesn’t have a TPS currently, you will need to add one. Some

older cars only came with TP switches for idle and WOT. These can not be used with NIRA i7x.

If you are planning to use Alfa-N calibration at low loads and expect to be able to adjust the calibration with good precision, you will need a TPS with excellent temperature stability and very high angular resolution.

When mounting the TPS make sure that it doesn’t bottom out before the WOT or idle stops. Verify this by observing the TPS while a helper depresses the accelerator fully and then lets the pedal go completely. At both end points there needs to be additional travel available for the TPS. If not, adjust the position of the TPS relative to the throttle shaft.

The TPS mounts on different sides of the throttle housing on different cars. This will cause the TPS to turn in different directions on different cars as the throttle opening increases. If the TPS signal on your car is reversed, simply swap the Throttle Sensor Ground and Throttle Sensor Supply wires.

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3.4 Manifold Absolute Pressure (MAP) and

Intake Air Temp (MAT)

When NIRA i7x is set up as a speed density system, precise knowledge of both the absolute pressure and the air temperature in the intake manifold are required in order to calculate the correct amount of fuel to inject.

If your vehicle already has MAP and MAT sensors you may be able to use those. The MAT sensor will need to react very quickly to sudden changes in temperature. This is especially important on a turbo charged engine where the intake air temp can increase 100 degrees Celsius within a few seconds.

Your NIRA i7x dealer sells an appropriate combined MAP-MAT sensor. This sensor is pre-calibrated in the NIRA rk software.

3.4.1 Mounting the MAP/MAT Sensor

The NIRA i7x MAP/MAT sensor mounts on a horizontal surface on top of the intake manifold after the throttle butterfly. (For manifolds with multiple butterflies, see

3.4.2 below.) Drill a 12 mm hole and mount the sensor with the sensing element pointing down in order to

avoid accumulation of droplets on the sensing element. When you drill the hole, make sure to vacuum up all shavings. Any shavings left inside the manifold can cause significant damage to the engine.

3.4.2 Multiple Throttle Butterflies

If each intake runner has an individual throttle butterfly you can still use a single MAP/MAT sensor provided you build a small, external plenum and attach the MAP/MAT sensor to it. The plenum volume should be around 200 ml. Connect the plenum to each individual intake runner, after the throttle butterfly, using hoses with restrictions. Make sure the restrictions are all the same size.

With this setup you can still use speed-density mapping, which offers greater accuracy and stability than using only the throttle angle (Alfa-N mapping),

despite MAP fluctuating at low rpm’s. Calibration is done by changing the

inner diameter of the restrictions. Measure the MAP signal at NIRA i7x with an oscilloscope. The MAP signal is between pins E.12 and and E.53 of the

Picture 3-4: MAP/MAT sensor may be secured using a cable tie if the wall thickness is too thin.

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Engine connector at NIRA i7x. When the engine is idling, the voltage is allowed to vary as much as +/- 15%.

If the voltage swings are greater you will need to decrease the restrictions. The decrease should result in lesser swings. Avoid using too small restrictions as this will slows the response time down.

There’s a configurable filter on the MAP input of NIRA i7x. The filter can be configured using the Advanced setting in NIRA rk. If the pressure variations are still too large because of significant cam intake and exhaust overlap (using very aggressive camshafts) NIRA i7x can be set up for Alpha-N calibration up to a certain MAP (e.g. 70 kPa) and then switch over to speed density mapping. This is described in detail in a section 5.1.1 below. Being able to switch between mapping modes like this makes NIRA i7x ideal for use with highly tuned engines.

3.5 Boost pressure sensor (pre throttle

pressure sensor)

Controlling boost pressure is essential on a turbo charged engine. A great pressure drop will occur over the throttle body at small throttle angles which causes even higher pressure before throttle. The high pressure before the throttle can damage both turbo charger and the piping. To avoid this, NIRA i7x can be configured to control the boost pressure against the pre throttle mounted boost pressure sensor.

Mount the sensor in the piping between the charge air cooler and the throttle body.

3.6 Engine Coolant Temperature

Sensor (ECT)

The ECT sensor is used by NIRA i7x to monitor overall engine temperature and for cold start enrichment. If you plan on using the ECT sensor that came with your engine you will need to know or establish its resistance as a function of temperature. This information is often available in the service manual for your car. Your NIRA i7x dealer sells an ECT sensor which has been pre-calibrated in the rk software.

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3.7 Manifold Air Temperature Sensor (MAT)

The MAT sensor is used for air density compensation at different intake air temperatures. Its function is very important on a turbo charged engine where the intake air temp can rise 100 degrees Celsius in mere seconds.

The MAT sensor needs to react quickly and must be properly calibrated. Your NIRA i7x dealer can recommend several combined MAP/MAT sensors that meet these requirements and have been precalibrated in the NIRA rk software.

If you prefer to use the original MAT sensor on your engine you need to know or establish its transfer function. (The transfer function describes the resistance of the sensor as a function of the temperature.)

Sometimes the existing MAT sensor is mounted before the throttle butterfly. In such situations it is recommended to move it after the butterfly, or better yet, use a combined MAP/MAT sensor mounted after the throttle plate, see section 3.4

For fast MAT response, use a sensor with a small sensor tip. This is very important on turbocharged engines where manifold temperature can rapidly increase. Even more important if you prefer to use MAT compensated ignition angle.

3.8 Lambda Sensor

It’s very important to have an accurate lambda reading

when calibrating your engine. NIRA i7x controls a Bosch LSU

4.9 oxygen sensor. The sensor is of pump current type and NIRA i7x will not need any external amplifiers or electronics to control it.

3.8.1 Lambda Sensor Mounting

To avoid that condensed liquids are collected in the sensor, a horizontal inclination of 10 degrees is needed. Due to the temperature limits, mount the sensor after the turbine with at least 10 degrees vertical inclination.

 Maximum exhaust gas temperature for the LSU 4.9 is 930 ºC.  Maximum temperature for the hexagon of the LSU 4.9 is 600 ºC

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10 degrees

Accepted mounting

angles

Correct mounting of LSU 4.9 sensor

Your NIRA i7x dealer supplies LSU 4.9 sensor kits. A harness with pre crimped NIRA i7x terminals is included.

3.8.2 Lambda Sensor Connections

LSU 4.9 Pin

Nira i7x Pin

Description

Pin 1

V.82 LS1 IP / APE

Pump current

Pin 2

V.66 LS1 VM / IPN

Ground Pump current

Pin 3

V.40 LS1 U- / H-

Lambda Heater PWM

Pin 4

V.75 LS1 U+ / H

Lambda Heater Supply

Pin 5

V.65 LS1 IA / RT

Individual trim

Pin 6

V.83 LS1 UN / RE

Nernest voltage

5 6

3 4

1 2

LSU 4.9 Connector, rear view.

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3.9 Exhaust Gas Temperature.

Being able to monitor the exhaust gas temperature is very important, especially on a turbo charged engine, in order to avoid engine damage and also to avoid over-cooling the combustion with too much injected fuel as this lowers engine power. The ALS feature of NIRA i7x also requires precise monitoring of the exhaust gas temperature.

Make frequent inspection of the sensor to make sure it is in order. A broken sensor will immediately destroy the turbo.

Picture 3-5: The NIRA EGTC sensor probe mounts where the headers collect, before the

turbo.

3.10 Anti Lag System (ALS) Switch

An external switch is needed to turn on/off the Anti Lag System. Mount the switch so it’s easily accessible for the driver. Connect two wires to the switch. The Button GND wire at one of the pins. The other pin connects to the wire marked “ALS Switch in, on=gnd” in the NIRA i7x harness.

3.11 Launch Control Button

A button is needed to activate Launch Control. Mount it so it’s easily accessible for the driver. Connect two wires to the button. Ground one of the pins with the “Button GND” cable. The other wire connects to the wire marked “Launch Button in, on=gnd” in the NIRA i7x harness.

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3.12 Aux Inputs

NIRA i7x is equipped with eleven Aux Inputs. All these inputs can be used in NIRA i7x FlexiPortsTM for user defined outputs or compensations.

 Two 0-5 Volt Analog input  One 0-12 Volt Analog input  Four Resistance reading 0-32 kOhm  Two Resistance reading 0-3200 Ohm  Two Digital input. Period time and duty is measured

3.12.1 Input Filters

All inputs to NIRA i7x, including the Aux inputs, can be filtered using the “Advanced” setting in NIRA rk.

Sometimes this is useful when dealing with noisy input signals in order to improve readability during data logging.

Before applying filtering to MAP, MAT and TPS inputs, make sure that you have an understanding of the effects of adjusting the filter. These input signals should normally never need to be filtered.

3.13 Ignition

NIRA i7x is designed to drive multiple ignition coils, either with built-in (active coil) or external drive electronics (for passive coil).

The ignition output signal from NIRA i7x is a signal between 0 and 5 Volts and triggers on a negative flank, i.e. when the signal goes from 5 Volts to ground.

NIRA i7x can control the ignition of up to eight cylinders without waste fire.

Ask your NIRA i7x dealer about high performance ignition coils

Ignition Coil Power Supply

Modern active coils consume a great amount of energy during dwell-time. At the end of the dwell time the current can reach values of nearly 20 Amperes. With increased rpm the dwell times are overlapping each other and the total current consumption increases even more. Make sure the coils are supplied by a sturdy relay with fuse. Connect with appropriate cable dimensions and well crimped terminals for both supply and ground wires.

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3.14 Fuel Pressure Regulator (FPR)

For NIRA i7x to correctly calculate fuel injector on- times, a linear fuel pressure regulator needs to be installed in the fuel system. In a linear FPR, the fuel pressure rises linearly as a function of the intake pressure.

When so called progressive or rising-rate regulators are used, FlexiPorts™ should be adjusted in a way that compensates the fuel injection according to the difference between a linear fuel pressure regulator and a progressive fuel pressure regulator.

3.15 Fuel Injectors

The fuel injectors are extremely important when tuning a high performance engine. Thus, choosing injectors with diligence is necessary. Below are instructions that aim to facilitate the process of choosing the right injectors for your engine.

For high impedance injectors, connect the wire marked “Fuel Injector X supply” and “Fuel Injector X” to each injector.

High impedance Injector

Pin 1

Fuel Injector X supply

Pin 2

Fuel Injector

3.15.1 Choosing the Injector Capacity

Do not choose injectors with overly large capacity if there is a need to calibrate lambda with precision at low-load conditions, e.g. for emissions tests.

No injectors are manufactured with high enough precision to avoid fluctuations in the injected amount of fuel due to temperature and other running conditions, especially when the fuel injector on-time is less than

1.5ms.

A good rule of thumb when sizing injectors is 500 cc/ 100 hp. I.e. 400 cc injectors on a 5-cylinder engine is enough for approximately 400 hp unless lots of additional fuel is needed to cool the combustion.

NIRA rk will automatically alert you if the injector ”bottoms out” and can’t supply enough fuel. The alarm is called ”DG Max Total Fuel Time”.

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3.15.2 Type of Injectors

NIRA i7x is designed to drive up to eight fuel injectors sequentially. Injectors for port fuel injection are ground controlled. Connect one of the injector terminals to +12 V (terminal 15 via Main Relay) and the other to one of the wires marked “-Fuel Injector 1-8” in the NIRA i7x harness. In sequential mode, on engines up to eight cylinders, keep it simple by using the wire marked “-Fuel Injector 1” for cylinder 1, the wire marked “-Fuel Injector 2” for cylinder 2 and so on.

If the injector coil resistance is 8,5 Ohm or less, an additional, external resistor needs to be added to each injector. This is necessary in order to avoid overheating the injector.

Injectors with coil resistance in the range of 2-5 Ohm work well with a 3.3 Ohm, 15 W resistor in series.

If the series resistance is too high, the injector on-time precision decreases at low-load conditions and it may be difficult to get the injectors to turn on if the battery voltage is low.

If you would like to calculate the series resistance yourself, use Ohm’s Law and size the resistance such that the power across the injector is in the range of 10-25 Watt, assuming normal battery voltage with the engine running (approx 14 Volt.) Do not go outside this range.

P = Power [Watt], V = voltage [Volt], I = current (Ampere)

(V/sqrt(P/R_injector)) – R_injector = R_series

E.g. R_injector = 3Ω, P = 15 Watt, V = 14 Volt

-> (14/sqrt(15/3))-3 = 3.3Ω. If you would have chosen 6.8Ω, the injector would only see 6 Watt. At

low battery voltages, such as during cranking, this would result in long, imprecise injector on times. NIRA i7x has negligible internal resistance on the injector output lines.

3.16 Boost Pressure Actuator

NIRA i7x is connected to a boost pressure actuator that controls the air-flow from the inlet to the turbo’s waste gate. By controlling the air-flow, electronically, NIRA i7x can control the boost pressure in a very accurate manner.

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Engine

Turbine

Compressor

Air Cleaner

Throttle

Boost

Actuator

Overview of a boost control system

Boost control actuators have three ports that are connected to

 Atmospheric pressure, R (Return). This port is closed whenever the

valve is inactive. When the valve is activated, this port is opened

 Pressure after the compressor, C (Compressor). The C-port is

always connected to port W. Generally, the C-port has a visible restriction

 The turbo’s wastegate actuator, W (Wastegate Clock). This port is

always connected to port C

Boost control valves have three port and two or three connection pins

NIRA i7x controls the boost pressure actuator by giving the valve a PWMsignal. A pressure drop that depends on the PWM-signal is created over the R-port and thus the pressure that reaches the waste gate actuator is

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controlled. NIRA i7x can be configured to use either a PWM output or an Hbridge output to control the boost pressure actuator. This configuration is done using NIRA rk.

Bypass flow through the Boost Pressure

Actuator dependent on the PWM through the actuator coil

Boost control valves either have two or three connection pins. The type of waste gate used and the type of boost control valve determines how the valve should be connected.

3.16.1 Boost Control Valve with Two Connection Pins

Connection of the sourcing and ground cables is arbitrary on two pin valves. If the waste gate clock gives a higher boost pressure when the W-port has a lower pressure, the cables can be connected according to the table below. The table below assumes that the boost control valve is made for 12 V sourcing.

Regular Waste Gate Clock

Pin 1

Boost Actuator supply

Pin 2

Boost Actuator

3.17 IAC (Idle Air Control)

At idle, the throttle butterfly is closed. In order to keep the engine from stalling, a small amount of intake air must be allowed to bypass the throttle butterfly. Stable idle speed is achieved by controlling the amount of bypass air and altering the ignition.

There are several different configurations for controlling the bypass air. Typically some sort of IAC valve or IAC motor is used. NIRA i7x can control the IAC valve/motor using an H-bridge.

0% duty

”C”

Compressor

”W”

Wastegate

”R” Return

100%

duty

”C”

Compressor

”W”

Wastegate

”R” Return

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Some possible IAC valve/motor configurations are:

 2-terminal IAC valve  3-terminal IAC reversible motor with 1 coil and 2 windings  3-terminal IAC reversible motor

3.17.1 IAC Electrical Connections

Connect a 2-terminal IAC valve to the harness:

IAC valve pin

NIRA i7x harness wire

IAC +

IAC -

The picture below describes the function of an IAC valve.

Note that at 0% duty cycle, the engine speed is high. The valve closes completely at around 30% duty cycle and then begins to open again, increasing engine speed.

Picture 3-6: IAC valve function

The varying duty cycle PWM signal from NIRA i7x is used to modulate the relationship between the opened and closed states of the valve, thus controlling the amount of bypass air that reaches the engine.

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3.18 Main Relay

Use the Main Relay to supply actuators and sensors that need 12 V supply. Examples of such actuators and sensors could be injectors, CAM sensor, ALS solenoid etc.

Se the picture below and connect each pin as described in the table.

Kl 87

Kl 30

Kl 86

Kl 85

Relay pin overview

Description

Connect to

Kl 30

12 V in

Battery. Connect fuse at this side

Kl 87

12 V out

To actuator and sensors that need 12V

Kl 85

Control solenoid –

Pin V.89 (Main Relay On = gnd)

Kl 86

Control solenoid +

Ign switch (kl. 15)

3.19 Fuel Pump Relay

Warning! Make sure that the fuel pump relay is installed correctly. An incorrectly installed relay may cause severe personal and property damage. Do NOT connect the relay directly to the battery. It must be connected to terminal 15.

Connect one side of the relay coil to terminal 15. Connect the other to the wire marked “Fuel Relay, on=gnd” in the NIRA i7x harness.

Always connect a fuse with proper rating.

Connect each pin due to table below.

Description

Connect to

Kl 30

12V in

Battery. Connect fuse at this side

Kl 87

12V out

Fuel Pump

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Kl 85

Control solenoid –

Pin V.72 (Fuel Pump Relay On = gnd)

Kl 86

Control solenoid +

Ign switch (kl. 15) or Main Relay kl. 87

3.20 Tachometer

A tachometer can be connected to the harness wire marked “Tachometer Out”. NIRA i7x, pin v.91, outputs a tacho signal similar to a normal distributor-based system. The pulses are 12 V and can be used to control most tachometers on the market.

3.21 ALS Solenoid

For the Anti Lag System to work, some sort of mechanism that can increase airflow to the engine is needed.

One method is to attach a solenoid to the throttle shaft and have the solenoid open the throttle somewhat. Another method is to add some sort of valve, which allows air to enter the intake manifold after the throttle plate. This is analogous to the function of an IAC valve.

If a separate mechanism is used, connect the positive terminal of the mechanism to Main Relay kl 87 and connect the negative terminal to the wire marked “ALS Solenoid, on=gnd” in the NIRA i7x harness. NIRA i7x can sink up to 2A on this pin.

3.22 Wheel Speed Sensors

Four wheel speed sensors can be connected to the ECU to detect vehicle speed and be used for traction control. The speed sensors need to be of the type Hall Sensor. This is not prepared in the wire harness and needs to be added by the user. Contact your supplier for NIRA i7x connector pins.

Before connecting supply to the hall sensors it is important to know how much current the sensors draws. This is often stated in the datasheet that comes with the sensor. Supply can be connected either on E. 7, E.28, V.16 or V.17. The sensors together should not draw more than 60mA on all the ECU pins suggested.

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Connect each pin due to table below.

Nira ix7 Pin

Description

Connect to

E.83 Aux PWM 1

Signal

Wheel Speed Rear Left

E.18 Aux Digital2

Signal

Wheel Speed Rear Right

V.87 Aux RPM 3

Signal

Wheel Speed Front Left

V.70 Aux RPM 4

Signal

Wheel Speed Front Right

3.23 Aux Outputs

NIRA i7x has four auxiliary outputs, marked ”Aux Relay” and ”Aux PWM1 - 3” in the NIRA i7x harness.

The aux outputs can typically be used to control a nitrous oxide injection system, water injection, a fan or a shift light. Each aux output can sink max 600mA current. They can not source any current, so if a sourcing output is required, a pull-up to +5V or +12V is necessary.

Aux Relay is a 1 ampere low side driver for relay with hysteresis function.

Aux PWM1 to AUX PWM3 is user defined PWM outputs controlled by 3d maps. All Aux PWM’s have different characteristics.

3.24 Mounting NIRA i7x in the Car

Mount NIRA i7x securely in a protected place in the passenger compartment. Avoid overly hot areas. The maximum ambient temperature without any cooling fan is 70 degrees Celsius.

If you’ve gone through the installation instructions above, the sensor/actuator side of the harness is now connected. Now connect the wire marked “ECU Supply 12V” to Battery through a 30 amp fuse. Connect the wire marked “KEY” to the ignition switch. Find an ignition switch terminal that’s powered

also during cranking.

Both NIRA i7x harness wires marked “ECU GND” must be connected to engine ground, either to the block or to the intake manifold. Do NOT connect the “ECU GND” wires to the body of the vehicle.

Supply the injectors by the NIRA i7x controlled Main Relay.

At this point all sensors needed to run the engine should be installed. Additionally, the fuel injectors, ignition coils and other parts of the engine should be installed.

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In order to be able to start the engine you need to calibrate NIRA i7x using NIRA rk. To ensure a successful calibration effort, it’s recommended that you study the NIRA rk sections in the handbook in order to understand how to use this tool to calibrate an engine before you try to start the engine the first time.

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NIRA rk Software

NIRA rk is used to calibrate NIRA i7x. NIRA rk is also used to log data for subsequent analysis while the engine is running. By using NIRA rk and applying your knowledge of engine tuning you can prepare for the calibration effort by entering certain parameters for your specific engine. This gives you a base calibration which will save you time later when you connect NIRA rk to NIRA i7x.

NIRA rk installs on a PC and connects to NIRA i7x via the Kvaser CAN dongle connected to your USB port.

4.1 Installation of NIRA rk

Minimum System Requirements:

 Windows 98/2000/XP/Vista/7  64 MB of RAM  20 MB disk space (100MB recommended)  800 x 600, SVGA color monitor (minimum 256 colors)  One available USB-port

To install NIRA rk on your PC, execute the NIRA-rk.exe file supplied on the memory stick that is part of your NIRA i7x package. This will launch the NIRA rk Setup Wizard, which will guide you through the installation process. Follow the directions in the dialog boxes.

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Picture 4-1: Setup Wizard used to install NIRA rk.

Once the installation is finished, NIRA rk i7x Street should be listed in your “programs” list on the start menu. The NIRA rk icon launches NIRA rk.

4.2 Getting Started

This chapter will give you an overview of NIRA rk and its functions. Do not connect NIRA i7x to NIRA rk until you’ve read this chapter and understand fully how NIRA rk operates.

4.2.1 Launching NIRA rk

Click on the Nira Race Key Motorsport icon in the installation directory (default is C:\Nira).

4.2.2 Welcome Screen

Once you have launched NIRA rk, you will see the Welcome Screen.

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Picture 4-2. Welcome Screen

In this screen you can choose among several options. Open File... lets you open an existing i3d file (a file with calibration data.) Read from NIRA i7x loads calibration data from NIRA i7x into NIRA rk. Start from Default starts NIRA rk with default settings.

If you are using an i3d-file supplied by your NIRA dealer, it’s recommended that you first make a copy of the file before making any changes. This way you can always return to the original file.

If you select ”Start from Default”, NIRA rk will start in a default mode and all

adjustments have to be done by you.

Picture 4-3: Opening an appropriate i3d.

4.2.3 Wizards

If you opted to start NIRA rk in default mode (see previous section), you must go through all Wizards before you can load any calibration data to NIRA i7x.

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This is necessary in order to ensure that you’ve entered appropriate values for all Engine Setup-parameters before you start mapping. Otherwise, the calibration effort may be unsuccessful, should it turn out that you’ve been calibrating with inaccurate basic engine setup parameters.

You can re-run any of the Wizards later, e.g. in order to read the extensive on-line help available in the Wizards or if you’ve changed one of the sensors.

All Wizards are available under “Wizards” in the main menu.

Any changes you make inside a Wizard only become permanent after you’ve selected ”Finish” on the last page of the Wizard. You can cancel out of the

Wizard at any time by closing the window (clicking on the “X” in the top right hand corner of the window.)

It’s very important that you go through all pages of all Wizards and

enter correct values.

Picture 4-4: NIRA i7x Wizard: Engine Specifications is one of the Wizards you must go

through before you’re allowed to upload data to NIRA i7x.

Once you’ve gone through all Wizards and entered correct values, it’s recommended that you save all current settings as an i3d-file. Use “Save As...” under ”File” in the main menu, or hit F4. Try to give the i3d-file a

descriptive name, perhaps including the date, since this will make it easier to find the file later.

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4.3 Using NIRA rk

Once you have selected and loaded an i3d-file, NIRA rk takes you to the Preferences window (Picture 4-5.) This screen tells you when the i3d-file was last saved on your computer’s file system and you can add comments.

At the top of the main program window, below the main menu, is a red bar with the word Offline in it. This status bar shows the state of the connection to NIRA i7x. In order to go online and be able to upload mapping data to NIRA i7x, you first have to go through all steps of all NIRA i7x Engine Setup Wizards.

It’s also possible to read any mappings already in NIRA i7x. (“Read from NIRA i7x” under “File” in the main menu.) Only use this option if you’ve previously gone online with NIRA i7x.

Picture 4-5: The “Preferences” tab lets you add comments and choose whether you want to

simulate engine running values (Engine Simulator) or connect to NIRA i7x.

Before attempting to connect to NIRA i7x, ensure that the drivers for the Kvaser USB-CAN dongle are installed on your computer. These drivers are available on the USB stick delivered together with NIRA i7x.

If you can’t connect to NIRA i7x, check the connection settings by clicking on ”Settings…”. This lets you choose the port to which NIRA i7x is connected. You can also launch ”Auto Find Target”, which searches all ports and selects

the one to which NIRA i7x is connected.

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4.3.1 Keyboard Help

A useful shortcut key to remember is F2. Holding down F2 brings up the Keyboard Help dialog box. The dialog box shows what can be done in the current view (and thus, it changes depending on the view.)

Picture 4-6: Holding down the F2 key brings up a window showing all available commands in

the current view.

4.3.2 Tabs

NIRA rk uses tabs to organize different views of parameters, graphs, tables etc. When a new window is opened a new tab is added. This allows for quick switching between views. Each new tab gets a number in addition to a name.

You can switch tabs by clicking on the tab with the mouse or by hitting the G key on the keyboard, which brings up the Change Page dialog box (see below) and then selecting the desired tab using the up and down arrows on the keyboard. Shift-G takes you directly to the next tab in order.

Picture 4-7: 'G' (or '5' on the numeric keypad with NumLock off) brings up the "Change

Page" dialog box.

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You can close a tab by hitting Esc or right-clicking on the tab and selecting "Close". The first five tabs can never be closed.

While in the Change Page dialog box, you can also close a page by selecting it and hitting the Del key on the keyboard.

4.4 Parameters

Calibration of NIRA i7x is done by assigning values to parameters in NIRA rk.

There are three main types of parameters:

 A monitor: Monitors typically represent physical values, such as RPM,

engine temp etc. These values come from input signals to NIRA i7x. Monitor values are written in black and are preceded by a blue arrow

. These parameter values cannot be changed. All monitors are

available under the category called “Monitor Output” found on the left side of the “Mappings” tab

 A value: Certain parameters are related to output signals from NIRA

i7x, e.g. to the fuel injectors or the boost pressure control valve. Other parameters are constants used by NIRA i7x to calculate output signals or interpreting input signals. Both types of parameters are written in green and can be changed by the user

 A table: Tables are the most powerful parameter type. They are used

for calibrating in- and output signals from NIRA i7x and allow for finetuning of the output signal value based on other parameters. A good example is the Fm Lambda Target, where lambda values are entered

based on RPM and MAP. Tables are marked by a -icon in front of the name.

NIRA i7x has a number of tables dedicated to setting up the Aux outputs, including which input signals are used to control the outputs.

Parameter values written in green can be changed. Those written in black cannot.

At the left edge of the Mappings tab is a folder view of all available parameters. The parameters are grouped into logical sets, such as Fuel, Ignition, Engine Start, etc. Subfolders further separate calibration parameters to make it easier to find and access the relevant parameters.

NIRA rk starts in Standard mode. If you feel that variables are missing you can select Advanced mode from the drop down list at the top of the main

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window. This setting exposes more calibration variables. It’s recommended that you leave the mode setting as Standard.

4.4.1 Sorting and Parameter Descriptions

Parameters can be sorted alphabetically, numerically or according to unit by selecting Item Name, Value or Unit respectively at the top of the parameter list. When you move the mouse cursor over a parameter a small help bubble will appear with information about the parameter. You can also press F1 to get the same information for any highlighted parameter.

Picture 4-8: A small help bubble appears when the mouse cursor is placed over a

parameter name.

4.4.2 Searching

You can search for a parameter by clicking on the magnifying glass icon ( ) or by hitting F on the keyboard. To go to the next parameter matching your search criterion, hit R.

Picture 4-9: Searching for a parameter.

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You can search for multiple parts of a parameter name by separating the

search criteria with spaces. E.g. ”th po” gives you a match for ”Throttle Position” and "sens la" would give you a match for “Lambda Sensor”. As you

type in the letters, the search result is updated continuously.

4.4.3 Alarms

In addition to the built-in diagnostic alarms in NIRA i7x, which, among other

things, check input signal levels, it’s possible to set user alarms using NIRA rk. Hit F5 or right-click on a parameter and choose “Set Alarm…”.

It’s only possible to set alarms on monitors (see section 4.4.) Monitors are

identified by a blue arrow ( ) in front of the parameter name. Once a monitor has an alarm associated with it, the arrow changes colors to red ( .)

4.4.4 Flags

As a tool to mark parameters, e.g. which parameters still need calibration,

there’s a flag feature available. Flag a parameter either by clicking in the flag

column of the parameter or by clicking on the “Toggle Flag” button. Monitor parameters (see section 4.4) cannot be flagged.

All parameters that have been flagged can be viewed in the “Flagged Items”

folder in the tree view to the left. Unflagged parameters can be viewed in the “Unflagged Items” folder.

4.4.5 Favorites

You can add parameters to a special folder called “Favorites”. This lets you collect parameters of particular interest for quick access later.

4.4.6 Changing Parameter Values

In order to change a parameter value, highlight it and then hit Enter on the keyboard. Alternatively, double-click on the parameter name. If you’re online

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with NIRA i7x at the time, any changes in the parameter value will be uploaded to NIRA i7x immediately. Otherwise, the changes will be uploaded next time you connect to NIRA i7x.

Picture 4-10: Double-clicking or hitting Enter lets you change a parameter value.

You can also change the value with the plus and minus keys. Enter the parameter addition/subtraction in the “+/-“ box above the list.

The delta is unique for each parameter, so if you want the same delta to apply to a number of parameters, you need to enter this value for each parameter.

4.4.7 Tables

Some parameter names are preceded by a grid icon ( ). This icon indicates that the parameter is a table. Tables can be two- or three-dimensional.

Tables control output values from NIRA i7x based on other parameter values. Typically these parameter values are sensor values, such as rpm or MAP.

Depending on the number of parameter values, the table is one- or twodimensional.

A typical one-dimensional table is the engine temperature sensor. The output is a function of a single parameter. When you map the temperature sensor you enter the temperature for different sensor signal voltages.

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Picture 4-11: A two-dimensional table; it uses rpm and MAP as input variables.

A two-dimensional table uses two input signals; one on the x-axis and one on the y-axis. The output signal is a function of both input signals, e.g. rpm and MAP.

4.4.8 Editing Tables

To edit tables, double-click on the parameter name or highlight the name and hit Enter. A new tab will open up displaying the table contents.

As always, F2 opens a window that lists all possible functions in this view.

There are multiple ways of changing table values. One way is to edit the content of each individual cell. Right-clicking on a table cell opens up a menu listing different options for editing the value.

Changing Multiple Cells

To edit multiple cells simultaneously, or have a formula affect multiple cells, the cells first have to be highlighted. See picture 4-13 below. Highlighting is done by holding down the left mouse button while moving the mouse, or by holding down the Shift-key while using the arrow keys to select the cells.

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Increasing/Decreasing Cell Values

A simple, straightforward way of working with cell values is to use the +, –, *

and / keys.

Picture 4-12: Enter the delta/ratio increase/decrease for the +, -, * and / keys.

The boxes above the table show the absolute increase/decrease of the cell values (for the + or – keys) or the %-age increase/decrease of the cell values (for the * or / keys.) In the case above, the value would increase with 0.1 if you hit the + key and increase 10% if you hit * key. If multiple cells are highlighted, they will all be affected.

Picture 4-13: Highlighting multiple cells in a table.

Filling Cells

If multiple cells are highlighted, they can be filled with the same value using a few different techniques.

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 Hit M to set all cells to the same value as the cell in focus. This cell is

blue in the picture above. The color may be different depending on the color scheme chosen for Windows

 Fill cells in one direction. It’s possible to fill cells to the right, to the

left, upward or downward. Choose direction by right-clicking and

selecting “Fill >” from the menu that opens up, or hit Ctrl-R, Ctrl-L, Ctrl-

U or Ctrl-D respectively

 More advanced fill patterns can be set up if you right-click and select

“Fill Series...” from the menu that opens up, or hit I on the keyboard.

A dialog box appears in which you can choose to interpolate horizontally or vertically, to fill all cells with the same value or to fill the cells with stepwise increasing values in different directions

Picture 4-14: The Fill Matrix dialog box offers more advanced cell manipulation options.

Modifying the Axis Values

The axis values can only be edited in offline mode. Changes applied in NIRA rk during offline adjustment take effect when the data is loaded to NIRA i7x by the user going online and choosing update NIRA i7x. Note that the axis values have to increase monotonously. This means that each value on the xaxis has to be greater than or equal to the previous value as you move to the right. The same rule applies to the y-axis as you move downward.

For safety reasons, a table that doesn’t follow these rules can not be uploaded to NIRA i7x and any online connection to NIRA i7x will be disconnected.

If an axis value is changed, all values in the corresponding column (x-axis) or row (y-axis) move to this new value. In other words, the mapping values move to a new axis value.

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You can switch quickly between the x-axis cells and the table cells by hitting

X or between the y-axis cells and the table cells by hitting Y. The arrow keys

can also be used; if you hit the up key when you’re in the top row of table cells, you’ll enter the x-axis. The same is true for the y-axis by hitting the left key when you’re in the leftmost column of table cells.

Adding Axis Values

The axis values can only be edited in offline mode

Modifying the axes often involves adding more points for greater resolution, rather than moving points around.

Picture 4-15: Inserting an x-axis column in order to add rpm values.

To add more points, right-click on an axis value, use ”Insert Column...” or “Insert Row…” respectively. You can also hit the Insert key on the keyboard. Both methods bring up a dialog box in which the new axis value can be entered. Note that the new value must be between the values to the immediate left and right or up and down.

The new column/row will automatically get interpolated table values, based on the new axis value. This way, the overall calibration doesn’t actually change until you change the table values explicitly.

Note: When a new column or row is added, the rightmost column or the bottom row will fall off the edge.

Drag Fill; Filling Axis and Table Cells

There’s also a function to fill entire columns or rows, including the axes. This can be done by dragging and dropping a single axis cell value onto a different axis cell value. You can also hold down the Ctrl key while using the arrow keys to perform the same function.

The entire column or row will be marked green. Once you let go of the mouse button or the Ctrl key, a dialog box will appear in which you can choose among different fill methods.

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Picture 4-16: Drag Fill: Filling axis and table cells.

When choosing ”Copy”, make sure the result of the copy doesn’t create an

axis with axis values that aren’t all equal or increasing looking rightward (xaxis) or downward (y-axis.) Should this happen anyway, NIRA i7x will go offline and you need to fix the axis values before you can go online again.

Undo/Redo

It’s always possible to undo any changes you’ve made to a table. As long as the table is open in a tab, NIRA rk remembers all changes and highlights any changed cells with an orange frame.

You can also undo undo, as long as you haven’t made any new changes.

This is called redo and is only available if you’ve undone something at least once.

The standard Windows Ctrl-Z och Ctrl-Shift-Z shortcuts also work, as well as U for undo och J for redo.

Copy/Paste

It’s possible to copy and paste cells within a table or between tables. You

can also copy and paste from other programs, such as Microsoft Excel.

When pasting cells, you have to mark the cells into which you want to paste data. This is different from software such as Excel and offers a level of protection against accidental changes.

Axis cells can also be copied and pasted. Mark the cells with Shift-Left arrow or Shift-Right arrow or Shift-click with the mouseIt’s not possible to drag and drop with the mouse due to the Drag Fill function described above.

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Graphical View

By hitting the F5 key (NumPad: Ins) you can switch to a graphical view of a table.

The graphical presentation is different for one-dimensional tables and multidimensional tables. Picture 4-17 below shows an example of the graphical view of a multi-dimensional table where the two axes create a 3-D surface.

Picture 4-17: F5 or the "Toggle Graphics"-button switches to a graphical view of the table.

This is a multi-dimensional table.

One-dimensional tables are shown as graphs. In the graph, the x-axis represents the axis cells and the y-axis represents the table cells.

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Picture 4-18: F5 or the "Toggle Graphics"-button switches to a graphical view of the table.

This is a one-dimensional table.

While in the graphical view, it’s possible to move among the cells and change their value with the + and – keys, just like in the table view.

Operating Point

When NIRA i7x is online, NIRA rk can show where in a table NIRA i7x is currently operating, the so-called operating point. This is very helpful during the calibration effort.

By checking the ”Follow” checkbox or turning this feature on/off with O, NIRA rk can move the currently highlighted cell to the operating point.

By hitting Space on the keyboard, you can manually move to the operating point. This affects all open tables such that the focus of each table moves to the operating point. If you want to modify multiple tables around the operating point, this can be very useful.

Picture 4-19: Jumping to the operating point using the Space key.

If ”Follow” is enabled (see above), or if you use Space to jump to the operating point, four cells around the operating point will be highlighted. The operating point is marked as a red bullet. If you use the +, –, / or * keys to

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modify the cell values, they will be modified in a weighted fashion, with greater weight given to cells closer to the operating point.

Example: In picture 4-19 above, the operating point is farther to the right than the left and thus, when using the +, -, / or * keys to modify the values, the cells to the right will be adjusted more than those to the left.

The operating point is visible in the graphical view as well and the same type of adjustments described above can be made in the graphical view.

Saving/Opening Tables

It’s possible to save an individual table in a file, an mtx-file. This file can be opened independently of the global i3d-file.

It’s also possible to associate a particular mtx-file with a quick-access button. There are four round, green quick-access buttons to the left above the cells in any open table. They are numbered 1-4. You make the associon by clicking on the small down-arrow to the right of the corresponding quick-access button. The file can be loaded later by clicking on the quick-access button, or by hitting Ctrl-1 through Ctrl-4 on the keyboard.

4.5 PID Controllers

NIRA i7 uses a number of PID controllers. A general functionality overview follows in this chapter.

4.5.1 What is a PID controller?

A PID controller is named after the Proportional, Integral and Derivative control modes it uses. PID controllers are used in most automatic process control applications in industry and automotive. PID controllers can be used to regulate flow, temperature, pressure, level, and many other industrial process variables.

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4.5.2 Feed forward table

Using a feed forward table is a prediction technique that estimates the output from the proportional-integral-derivative (PID) control algorithm without waiting for the PID algorithm to respond. If the feed forward prediction can estimate the control output closely, the PID algorithm, whose job it is to minimize the error between the current state of the system and the desired state, will need to do less to correct the error. This reduces the error faster or keeps the error smaller than relying on the PID algorithm alone.

4.5.3 Proportional factor

The proportional factor is easiest to understand: The output of the proportional factor is the product of gain and measured error. Hence, larger proportional gain or error makes for greater output from the proportional factor. Setting the proportional gain too high causes a controller to repeatedly overshoot the setpoint, leading to oscillation.

The downside to a proportional-only loop is that when error becomes too small, loop output becomes negligible. Therefore, even when the proportional loop reaches steady state, there is still error. The larger the proportional gain, the smaller the steady state error, but the larger the proportional gain, the more likely the loop is to become unstable. This dilemma leads to inevitable steady-state error called offset.

4.5.4 Integral factor

Think of the integral factor as a basket in which the loop stores all measured error. Remember that error can be positive or negative, so sometimes error fills the basket (when positive error is added to positive error or negative error is added to negative) and sometimes it empties the basket, as when positive error is added to negative, or vice versa.

When the integral factor functions properly in the control loop, the basket is nearly empty. Even when error is so small that the proportional factor is no longer effective, the integral is still hard at work, collecting error until it is large enough to matter, as part of the integral's function is to eliminate steady-state offset.

In fact, most control loop action at steady state is due to the integral factor.

The downside to the integral factor is that it strongly contributes to controller output overshoot past the target setpoint. The shorter the integral time, the more aggressively the integral works.

4.5.5 Derivative factor

The derivative factor is the least understood and used of the three factors. In fact, a majority of PID loops in the real world are really just PI loops. That does not negate the fact that there are certain applications in which the

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derivative plays a very important role. The proportional corrects instances of error, the integral corrects accumulation of error, and the derivative corrects present error versus error the last time it was checked.

In other words, the derivative is looking at the rate of change of the error. The more error changes or the longer the derivative time, the larger the derivative factor becomes. The effect of the derivative is to counteract the overshoot caused by P and I. When the error is large, the P and the I will push the controller output. This controller response makes error change quickly, which in turn causes the derivative to more aggressively counteract the P and the I. A properly used derivative allows for more aggressive proportional and integral factors. Larger derivative time makes the derivative more aggressively dampen P and I.

4.6 Gauges

NIRA rk offers a number of different ways to view input signals, e.g. from sensors.

4.6.1 Sensor Bar

Sensor Bar is the name of the panel at the bottom of the screen. The selection of parameters in the bar is fixed. However, there are a number of different Sensor Bars available, each with a different selection of parameters. Switch among the different types by hitting T on the keyboard until you find the appropriate one for your current mapping situation. You can also hide the sensor bar, e.g. if you want the extra space on the screen or if you feel that other parameters on the screen are updated too slowly.

Picture 4-20: Sensor Bar "GENERAL" contains a set of general parameters.

4.6.2 Dashboard

There’s a predefined dashboard in NIRA rk. It contains a few standard gauges. The selection of gauges offer an easy general system check, and

they’re also very useful to display on your notebook computer when you’re

testing NIRA i7x in a vehicle or dyno.

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Picture 4-21: NIRA rk Dashboard.

The Dashboard is brought up by hitting F7 on the keyboard. The Dashboard is available in two versions. The difference is the rpm range. One version goes up to 7000 rpm, the other to 11000. Choose the most appropriate one for your engine.

4.6.3 Panels

Unlike the Dashboard, the Panel tab is completely flexible. You can add any parameter of interest in the form of a gauge. The selection of gauges can be saved as presets so you can quickly switch among different panel setups.

Picture 4-22: The Panel tab allows you to add any parameter of interest.

To add a gauge to the panel, hit Ins on the keyboard or click on in the top left corner.

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By moving the mouse pointer over a gauge, alternative display options will be shown as buttons that can be clicked. You can move a gauge by dragging and dropping the gauge. The panel has an invisible grid to which a gauge will snap when moved. This makes it easy to create panels with a clean, organized look.

Picture 4-23: By moving the mouse pointer over a gauge, display options are shown as

buttons that can be clicked.

Referring to picture 4-23 above:

Clicking on the X in the top right corner of the gauge removes the gauge from the panel.

The buttons at the bottom of the gauge change the look of the gauge:

• VAL means Value. Selecting this option turns the gauge into a simple value display. The Battery Voltage gauge in picture 4-22 is an example of the Value look

• m/M means min/Max. Selecting this option turns the gauge into a Value display (see above) with additional min/Max displays. A Reset button lets you set the min/Max values to the current value

• GAU means Gauge. Selecting this option turns the gauge into a traditional analog gauge. The RPM gauge in picture 4-22 is an example of the Gauge look

• Plot turns the gauge into a histogram, moving from right to left. The width of the histogram is relatively short, which means it’s mostly

useful for looking at short-duration events. If you want to capture longer durations and graph them, use the logging feature in NIRA rk. See section 4.7

• BAR turns the gauge into a bar graph. The Engine Temp gauge in picture 4-22 is an example of a bar graph

In the Gauge, Plot and Bar modes, there’s a ”Set” button. Double-click on it or hit Enter to modify the range of the gauge or to revert to the default range.

As always, F2 opens a dialog box listing all possible short cut keys.

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4.7 Logging

NIRA rk includes a powerful logging feature. Any parameter can be logged

and there’s no limit to the number of parameters that can be logged.

However, as the number of parameters increases, the sampling rate decreases.

The log can be saved to a file and shown graphically.

4.7.1 Inspect

At the heart of the logging function is a function called Inspect. Inspect allows you to select a set of parameters at which you want to take a closer look, e.g. by logging them.

Parameters being inspected are shown with min and Max values, even when actual logging isn’t active. This can be useful when you calibrate your engine.

Inspect resides in a separate window at the bottom of the screen. The window has three display modes; full view, partial view and minimized view. You can cycle through the modes with F6, or by clicking on the Zoom button at the far right of the Inspect window. You can also resize it by clicking and dragging the top of the window up and down.

Picture 4-24: Inspect. Cycle through the different display modes using F6 or the Zoom

button.

Selecting Parameters

To add a parameter to the Inspect window, highlight it in the Mappings tab

and click on the ”Add to Inspect” button at the top of the window,

alternatively hit I on the keyboard.

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If you would like to add more parameters from within the Inspect window, you can use the -button. To remove a parameter, use the Del key on the

keyboard or use the -button.

Saving/Opening Presets

It’s possible to save parameter selections and assign them to the four round, green buttons at the top of the Inspect window. By clicking on the arrow to the immediate right of a button, a menu will open up giving you the option of assigning the parameter selection to the button.

NIRA rk comes with four different parameter selections already assigned to the four buttons.

4.7.2 Basic Logging

To start logging of the parameters in Inspect, hit F8 on the keyboard. This can be done from anywhere in NIRA rk, whether you’re calibrating a table, showing gauges or reading help screens.

Note: When logging is active, no parameters are updated in NIRA rk. The reason is that NIRA rk instead tries to sample the logging parameters as fast as possible. The operating point is updated, though, and all alarms are still active.

Parameter values that aren’t being updated while logging is active change to dashes, "--", so you can always trust any number that’s shown.

Picture 4-25: The top of the Inspect window turns red when logging is active.

To stop logging, hit F8 on the keyboard. This will also open up a dialog box, which gives you the option of saving the log as a file for later analysis.

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4.7.3 Advanced Logging

Sometimes it is useful to be able to start logging whenever a parameter goes above or below a certain value. Likewise, it may be useful to stop logging whenever a certain event happens. For such situations, there’s a trig function in NIRA rk.

Clicking on the -button or hitting F5 on the keyboard opens up a dialog box in which you can set conditions for starting/stopping the logging and how many seconds before/after the trig point you want to be part of the log.

4.7.4 Opening an Existing Log File

You can open an existing log file by selecting ”Load log file…” under File in the main menu or by hitting Ctrl-F8 on the keyboard.

Note: You can also load NIRA rk log files in MATLAB.

4.7.5 Graphical Presentation

Select the ”Plot” tab to view the logging graphically.

Picture 4-26: Graphical view of logged parameters.

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Data from multiple parameters can share the same plot window. Each parameter has its own, adjustable y-axis at the left edge of the window.

Adjusting the View

There are multiple tools available to zoom and pan. Click and drag on an axis to pan. Zoom by moving the mouse perpendicularly against an axis.

It’s also possible to adjust the range of an axis by double clicking on the axis

or by clicking on the Set-button at the bottom of each axis.

Removing an Axis

Removing an axis (and the associated sampled parameter) can be done by clicking on the X at the top right corner of the axis in question. You can deactivate an axis by un-checking the checkbox to the immediate left of the Set-button at the bottom of the axis.

Adding an Axis

To add an axis, click on .

4.8 Locking the i3d Data Set

Protect the i3d data file by choosing File  Lock i3d Data Set… A password can be entered that will disable access to the calibration data developed, unless the password is entered when the data is loaded to NIRA rk.

4.9 FlexiPorts™ - Set up

Example for setting up a FlexiPort for boost controller.

 Choose one of the auxiliary temperature inputs and install a switch or

potentiometer to that input.

I.e pin 28. Named T3 in Nira rk.

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 Open Nira rk

- Under Boost Control you will find Flx Bc Flexiport Ff Comp Y.

- Instead of engine speed, choose Ain T3 Resistance to use the T3

input.

- Open the Bc Flexiport Comp and set it up accordingly to your switch

or potentiometer. E.g like below for a grounded switch.

Positive values will be added to the boost setpoint and negative values will subtracted from the boost setpoint.

If open loop control is used there is a correlating table for that.

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4.10 Auto Fuel Calibration

Auto Fuel Calibration is a very useful tool when setting up the Volumetric Efficiency Table. See section 6.3.3 for more information about this table.

To activate Auto Fuel Calibration, hit F11 on the keyboard.

For a complete description of Auto Fuel Calibration, see section 6.3.5.

4.11 Ignition/Fuel Mapping

There’s a special split-view window for the VE and Ignition tables. Hit F12 on the keyboard to bring up this view. Hit F12 repeatedly to cycle through the individual tables and back to split view. Hit N to jump between tables in the split view.

As always, F2 gives you a list of all possible keyboard shortcuts.

Starting the Engine

If you’ve read the previous chapters and followed the installation instructions, NIRA i7x should be installed in your vehicle and you have an understanding of how NIRA rk is used. This chapter describes how to start the engine in a safe manner.

Warning! It is absolutely essential that you set up all parameters correctly under the Engine Setup tab. Failure to do so can easily cause permanent damage to your engine, and also cause risks of personal injury.

5.1 Setting Up Parameters Offline

Before you turn on the ignition in the car you must set up all parameters under the Engine Setup tab using the NIRA i7x Engine Setup Wizard. Once

you’ve completed all steps in the wizard you can edit individual parameter

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values. Make sure you complete all steps in the Wizard before you upload the settings to NIRA i7x by going online.

5.1.1 Engine Setup -> Crank Cam

It’s essential that the Crank & Cam settings are set properly to get synchronization of the Crank & Cam relationship. All labels in the “Crank Cam” folder are named with the prefix “Tpu”. This means that they are handled by a dedicated part of the CPU. Changing these labels implies that KEY has to be switched off and on for the changes to take effect.

Crank and cam related labels are found under.

Engine Setup -> Crank Cam

The Crank related labels are:

 Tpu Crank Lost Teeth: The numbers of missing teeth at the crank

wheel. For a “60-2” wheel this label should be set to 2

 Tpu Crank Polarity: Select which flank on the crank trig that the system

detects. Can be either falling or rising

 Tpu Crank Sensor Select: Choose type of crank sensor. Can either be

Hall or Inductive. Note that there are different connections for different sensor types

 Tpu Crank Threshold  Tpu Crank Total Teeth: Number of teeth on the crank trigger wheel.

For a “60-2” wheel this label should be set to 58

The Cam related labels are:

 Tpu Cam Polarity: Select which flank on the cam trig that the system

detects. Can be either falling or rising

 Tpu Cam Sensor Select: Choose type of CAM sensor. Can either be

Hall or Inductive

 Tpu Cam Window Start: From this point the system looks for a cam

sensor transition. The transition should occour whitin number of csd set in TPU Cam Window Width

 Tpu Cam Window Width: Set the distance from TPU Cam Window

Start that the transition should occur within

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First teeth

Cam Window Start

Two revolutinos, 720 degrees

Cam Window Width

Scope picture of 24-1 crank wheel and a cam wheel with one tooth

Example. The picture shows a scope picture of two crank revolutions with Hall sensors at both crank and cam.

It is a 24-1 wheel. Every tooth is 360/24 = 15 degrees/tooth

Tpu Crank Lost Teeth should be set to 1

Tpu Crank Polarity is Falling. The system looks for the first falling edge after the lost gap. (see red vertical lines)

Tpu Crank Sensor Select should be set to Hall

Tpu Crank Total Teeth should be set to 24-1 = 23

The blue opaque field shows an area where the cam shaft sensor gives a rising edge

Tpu Cam Sensor Select should be set to Hall

Tpu Cam Window Start correspond to teeth nr 6: 6 * 15 = 90 degrees

Tpu Cam Window With correspond to teeth nr 4: 4 * 15 = 50 degrees

Tpu Cam Polarity correspond to the cam signal transition from low to high level within the blue field: Rising

5.1.2 Engine Setup -> Engine Specifications

Engine Specifications is related to the engine hardware. Values entered in this section are used for air mass, fuel mass calculations and cylinder individual timing.

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Bv Cylinder Volume

Swept cylinder volume for one cylinder. If your engine has 4 cylinders and a total displacement of 2000 cm3, the cylinder volume for one cylinder is 2000 / 4 = 500 cm3.

Bv Tdc Cylinder (firing order)

Tdc angle for each cylinder with cylinder 1 as reference. Cylinder 1 is always zero. A cylinder that’s not in use is set to -1. This relationship is based on the crankshaft layout and the angles between the cylinder banks if it’s a Vengine.

Example.

An in line 4 cylinder, four stroke engine with firing order 1342.

A four stroke engine needs two engine revolutions to complete all four strokes = 720 degrees.

Inline fours usually have symmetrical spread out firing order.

The angle between TDC. 720 / 4 = 180 degrees which is the distance to next cylinder TDC.

Cylinder 1: Always set this one to 0

Cylinder 3: 0 + 180 = 180

Cylinder 4: 180 + 180 = 360

Cylinder 2: 360 + 180 = 540

Example of TDC relationship at an 4 cyl with firing order 1342

Bv Tdc Cylinder Offset

You need to know the angle between the reference point of the pulse wheel

(“1 lost” or “2 lost”) and TDC for cylinder 1 on the trigger wheel used for the

CKP sensor. See section 3.1.2. This value needs to be entered in Engine Setup –> Engine Specifications –> Bv Tdc Cylinder Offset. Once you have

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done this, enter a rough, basic ignition map or use the map in the default data set that comes with NIRA rk.

The offset is a constant and rarely has any significance beyond it’s function as a basic reference. Use a timing light and check the angle at a specific RPM and then compare this value to Cyl 1 from 2 lost if you do not already know what the offset is on your particular engine.

First teeth

Two revolutinos, 720 degrees

Tdc Cylinder Offset

Cyl 1 TDC

Cyl 3 TDC Cyl 4 TDC Cyl 2 TDC

Bv Tdc Cylinder

Example of a four cylinder engine with symmetrical firing order 1-3-4-2 and 90 degrees

offset to tdc at cylinder 1.

Example. The picture shows a scope picture of two crank revolutions of an inline, four cylinder, engine.

It is a 24-1 wheel. Every tooth is 360/24 = 15 degrees/tooth

Bv Tdc Cylinder Offset. In this case the relationship between crank wheel mounting made the offset to 90 degrees (6 teeth).

5.1.3 Engine Setup -> Fuel injectors

The fuel injector parameters are used to calculate the injector opening time based on the requested fuel mass.

Injector offset

In NIRA rk there’s a table called Injector offset. This is the injector dead time at different battery voltages. This table is important to adjust correctly down to 0.1 milliseconds. The table gives NIRA i7x information about where the

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injector curve crosses the x-axis as well as the slope of the curve during lowload conditions

Injector offset is not the same thing as injector on-time because of the nonlinearity of the injector right after it has opened. The non-linearity is significant for the first 2ms, which is one of the reasons mass produced vehicles never have higher capacity injectors than absolutely necessary. (With a higher capacity injector, the total on-time would decrease, and more of the on-time would be spent in the non-linear territory, resulting in unpredictable emissions etc.)

Since NIRA i7x is a fully sequential system, the on-time per injector is double

that of a system that’s not fully sequential. The result is that you can use

larger injectors and the injectors will still spend most of their time in the linear territory.

If you are guessing as to what the injector offset values should be and you’re off, you may notice problems with lambda drifting with the intake temperature during low-load conditions. If the offset is far off you will have problems starting the engine. Two tenths (0.2) of a millisecond is considered a large error.

When using the Wizard in NIRA rk, look at the graph (F5) for “typical injector” and you will notice how the offset changes significantly based on the injector

supply voltage (battery voltage). It’s easy to understand that 0.2 milliseconds

will result in a lambda change of several percent at idle since the total injector on-time may only be around 2ms at idle.

As stated above, the problem is more pronounced if you are using a semi-

sequential setup. If you don’t have access to the offset values or can’t

measure them yourself, it’s recommended that you use a type of injector for which NIRA has already determined the offset. The Wizard lists the pre-

measured injector types. Otherwise, choose ”typical injector” in the Wizard.

This gets you a base mapping you can use as a starting point for many highresistance injectors and many low-resistance injectors (using the NIRA resistor pack mentioned above.)

Injector gain

Injector gain is the fuel injector characteristic without the offset. This value is used to calculate the injection time based on the amount of fuel to be injected.

NIRA i7x controls the fuel injectors based on how many milliseconds it takes to inject exactly 1 gram of fuel with the given fuel injectors. This time is

entered in the ”Injector Gain” parameter. NIRA rk has a wizard which helps

with the calculation of injector gain.

 The capacity of the injectors at a given fuel pressure and 100 % duty cycle

(i.e the injector is open all the time) and the density of the fuel. Note that

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some injector capacity ratings are given for 80% duty cycle and some for 100% duty cycle, often leading to confusion

 The safest thing to do is to measure your particular injectors. Before

doing that, check in the NIRA rk Wizard if your injector type is available as a “preset” type. If it is, you don’t need to measure things yourself.

In the example below the injector capacity is 400cc/minute at 3 bar pressure using gasoline.

The density of gasoline from a retail chain such as OKQ8 is 750 kg/m3 at 15°C. You need to convert these values in order to calculate Injector Gain because NIRA i7x needs to know the weight of the fuel being injected, not the volume.

The weight in grams of the fuel depends on:

 Fuel density. The density is different for 98 octane gasoline, racing

fuel, E85, ethanol and methanol. Even within a category the density can be different. As an example, the different racing fuels offered under the VP brand differ with up to 15%

 The temperature of the fuel

If you expect to use a different fuel pressure than the pressure at which the capacity was determined, an approximation is that the Injector Gain value changes with the square root of the pressure ratio.

Example:

400 cc at 100% duty cycle and 3-bar pressure

At 4-bar pressure: sqrt(4/3) = 1,155 X 400 = 462 cc

If you use regular retail gas and the temperature of the fuel is 15°C and the pressure is the same as when the capacity was determined and the duty cycle is 100%, the formula for Injector Gain is trivial:

Divide 80000 into the number of cc/min. This gives Injector Gain

Example: 80000/400cc = 200 ms/g

The Wizard has additional information on this topic. Enter the value in the Injector Gain parameter in Engine Setup in NIRA rk.

5.1.4 Engine Setup -> Fuel Specifications

Fuel specifications are used to compensate the amount of fuel based on the fuel characteristics.

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Bv Fuel Density & Bv Fuel Density Corr

Bv Fuel Density gives the base value of the density in kg/L.

If fuel temperature is measured, it’s possible to compensate the fuel density due to the temperature. The table Bv Fuel Density Corr gives a percentage correction of the density. If the Bv Fuel Density Corr is equal to -6% the final Fuel density is equal to Bv Fuel Density * (100 + Bv Fuel Density Corr)

Example:

Bv Fuel Density = 0,715 kg / L This value correspond to a fuel temperature of 15 degrees Celsius.

The fuel temperature is measured to 55 degrees Celsius.

55 degrees Celsisus gives Bv Fuel Temperature Corr = -2.9%

The final fuel density used in calculations will be

0,715 * (1-0,029) = 0,694 kg / L

Fm Af Ratio (Fuel mass Air to Fuel Ratio)

Fm Af Ratio is the stoichiometric air to fuel ratio of the fuel you use.

The Air to Fuel ratio defines by “air mass” / “fuel mass”

Read more about AF, stoichiometric mixture and Lambda in Relationship Between A/F and Lambda

Example of stoichiometric A/F ratios:

Air/98 Octane Gasoline = 14,6

Air/Methanol = 6,8

Air/Ethanol = 9,0

Air/E85 = 9,8

5.1.5 Engine Setup -> Sensors

All sensors that are necessary for engine control are found in this category. Auxiliary sensor input is found under Mappings -> Aux Input

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Pressure Sensors

Enter the minimum and maximum defined voltage in the x-axis. Enter the corresponding pressure to the minimum respectively maximum voltage in the table. Pressure output will be linearized for voltage measurement in between the min and max voltage value. Note: It’s only allowed to edit axis value while you’re offline.

Example calibration data for a pressure sensor from the sensor data sheet

P1 = 50kPa, P2 = 400kPa

Example of pressure sensor characteristic in NIRA rk

Each pressure sensors has a low pass (LP) filter possibility for smoothing out and filtering disturbances.

The filter constant for the LP filter is named Bv XX Pressure Filter. The unit is mS and values between 0 and 3276,7 mS are allowed.

Sensors for engine control

Pressure Measurement

Name in Nira Rk MAP

BV Manifold Air Pressure

Boost Pressure

Bv Boost Pressure

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Pressure sensors for auxiliary engine control or logging purpose

Pressure Measurement

Name in Nira Rk Fuel Pressure

Bv Fuel Pressure

Oil Pressure

Bv Oil Pressure

Temperature sensors

Characterize the temperature sensor by entering the correct temperature for

the given resistance.It’s possible to adapt both axis value and table value to

achieve the right sensor curve.

Note: It’s only allowed to edit axis value while you’re offline.

Example of temperature sensor characteristic

Temperature sensors for engine control

Temperature Measurement

Name in NIRA rk

Coolant Temperature

Bv Coolant Temperature MAT

Bv Manifold Air Temperature

Temperature sensor for auxiliary engine control or logging purpose

Temperature Measurement

Name in NIRA rk

Boost Temperature

Bv Boost Temperature

Fuel Temperature

Bv Fuel Temperature

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Oil Temperature

Bv Oil Temperature

Exhaust Gas Temperature (EGT)

Three different types of EGT-sensor inputs are available.

Choose your Temperature input at:

Engine Setup -> Sensors -> Bv Exhaust Temp Source

Nira i7x handles

Temperature Input

Name in Nira Rk

Signal Description

Digital

Bv EGT Digital

Temperature depended duty cycle of a square wave provided by external amplifier.

Resistive

Bv EGT Resistive

Resistance measurement of

Pt200 or Pt1000

Analog

Bv EGT Analog

0 – 5 V provided by external amplifier

Throttle or Acceleration Pedal Position (APP)

For Throttle calibration the system needs to be switched on. The procedure is described in the Online Chapter

5.1.6 Mapping -> Fuel -> Basic

Labels related to Air- and Fuel Mass are found under the fuel map in the Mappings tab. Prepare tables as far as possible to speed up the process.

Volumetric Efficiency Table

This is the heart of the fuel calibration. It describes the breathing of the engine, (i.e. the volumetric fill rate of the cylinders).

Before starting you need to select load signal and set up proper axis. For boosted engines the wizard can help you with preset tables.

Selecting load signal (Volumetric Efficiency Y-axis)

Either the MAP input (speed density calculation) or the TPS input (Alfa-N calculation) or a combination of the two can be used as the load signal. The Volumetric Efficiency table has a FlexiPorts™ Y-axis which makes the load

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signal user defined. The default Y-axis is Am Kvol Map which is the one Nira recommends using. Am Kvol Map is the output from the Throttle to Map table combined with the MAP sensor reading. The weight of these two inputs is determined by the data in the Load Select Factor table as described below.

Throttle-MAP-mix

In engine setups where an accurate MAP-reading is not possible at low loads, the Throttle To MAP function is helpful.

Two common cases where MAP reading is not an appropriate load signal:

 MAP sensor used for high boost pressure readings do not read low

pressure which is one reason of using Throttle MAP mix for accurate low load mapping

 N/A engines with high performance cam shafts do not produce low

pressure in the intake manifold.This is another reason of using throttle to MAP mix for accurate low load mapping

The table Load Select Factor determines how much the load signal is determined by the TPS and how much it is determined by the MAP. These

settings are made in “Advanced” mode. The values entered into Throttle to

MAP Table are used by the system as an approximation of the manifold air pressure as a function of RPM and TPS. If the engine is run without a MAP sensor, the engine load is entirely determined by the Throttle to Map Table.

Control the mix factor in the table.

Mapping -> Fuel ->Basic -> Load Select Factor Table

0% means that only MAP sensor reading is used.

100% means that only throttle position is used to estimate the pressure. The estimated pressure is entered in the table below.

Mapping -> Fuel ->Basic -> Throttle to Map Table

For value in-between 0% and 100% a weighted MAP values is calculated from the MAP sensor and from the Throttle to Map Table. The weighted MAP value is used in the Volumetric Efficiency Table.

Calculation of MAP value used in the Volumetric Efficiency Table

The MAP value used in the Volumetric Efficiency Table will be.

AM Kvol MAP = Load Select Factor * Throttle to Map Table +

(100% - Load Select Factor ) * MAP sensor reading

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Example

A turbo charged engine has a MAP sensor that reads 50 -350 kPa.

The actual Manifold Air Pressure at idle is 35 kPa even though the sensor output says 50 kPa.

By setting the Load Select Factor to 50% at small throttle angles and low engine speed and the Throttle to Map Table to 20 kPa it’s possible to use MAP values that are lower than the sensor reading.

The MAP value used in the Volumetric Efficiency Table will be.

AM Kvol MAP = 50% * 20 kPa + (100% - 50% ) * 50 kPa

AM Kvol MAP = 10 kPa + 25 kPa = 35kPa.

Alpha-N

It’s possible to run NIRA i7x in pure Alpha-N mode. The Volumetric Efficiency Table has a FlexiPorts™ Y-axis which enables the user to choose the load signal.

The FlexiPorts™ setting for the Volumetric Efficiency Table is found under.

Mapping -> Fuel ->Basic -> Volumetric Efficiency Y-axis

Click on the label to choose AM Throttle position and press enter to confirm your choice. Note the Volumetric Efficiency Table must be closed and NIRA rk must be offline when the Y-axis is changed. This option will change the Yaxis. Set up proper axis to make the Volumetric Efficiency table look similar to the picture below for pure Alpha-N mode.

Example picture of a Volumetric Efficiency table with Throttle Position aa Y-axis

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Vol Eff Compensation Cyl 1-8

Cylinder individual Volumetric Efficiency for all cylinders. If air flow phenomena change the air distribution in between the cylinders, the fuel calculations should be adjusted.

With Vol Eff Compensation Cyl 1-8 it’s possible to correct VE for every cylinder at different speed and load. Use individual lambda sensors or exhaust gas temperature sensors to evaluate air distribution issues.

96% : VE for this cylinder is -4% related to the value in the Volumetric Efficiency Table.

100% in these tables means no correction.

103 % VE for this cylinder is +3% related to the value in the Volumetric Efficiency Table.

The total sum of all cylinder’s corrections should be as close to zero as possible. If all cylinder corrections are greater or smaller than zero the Volumetric Efficiency Table is not correctly calibrated.

Set up proper axis before going online.

The Volumetric Eff Compensation Cyl1-8 tables are equipped with Nira

FlexiPorts™.

The FlexiPorts™ settings for the Volumetric Eff Compensation Cyl1-8 tables

are found under.

Mapping -> Fuel ->Basic -> Vol Eff Comp Cyl 1-8 Y-axis.

If a pure Alpha N is used. Change the Vol Eff Comp Cyl 1-8 Y-axis to values

to AM Throttle position.

FM Lambda Target

FM Lambda target is used to calculate the fuel mass based on the air mass filled in to the cylinder.

Set up proper axis of the Lambda target based on the Boost target. Presets are available in the Wizard.

FM Lambda Target is equipped with Nira FlexiPorts™

Default Y-axis is AM Kvol MAP.

The FlexiPorts™ setting for the AM Kvol table is founder under.

Mapping -> Fuel ->Basic -> Flx FM Lambda Target Y.

If a pure Alpha N is used. Change the Flx FM Lambda Target Y to

AM Throttle position.

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5.1.7 Mapping -> Fuel -> Injection Control

Injection Stop Angle

Control the injection stop angle in this table. The angles relate to the TDC after intake stroke.

 Angles near 180 degrees are shortly before the intake valves closes.  Angles near 360 degrees are shortly after the intake valve opens.

Depending on the crank and connection rod geometry the maximum piston speed is reached in angles smaller the 270 degrees.

Set up proper axes. Start with s small area of cells used. Expand it later or when/if expansion is needed.

5.1.8 Mapping -> Fuel -> Acceleration

The acceleration system is built up with two imaginary acc tanks that can be filled by quick throttle opening and drained by quick throttle closing and by the fuel in the imaginary tanks being injected into the engine. The unit of the acc tanks is in milligram [mg]. Therefore the amount might need adjustments based on the engine displacement and type of fuel.

The two different acc tanks are

 Fast acceleration tank will be injected during the two first rounds after

the throttle angle has been increased

 Slow acceleration tank. Will be injected during a numbers of rounds

after the throttle angle has been increased

Fm Acc Enrich Enable

Enable or disable the Acceleration Enrichment with the label

FM Acc Enrich Enable

Do always start your adjustments with acceleration enrichment disabled.

Adding fuel to a tank

Only a rapid movement of the throttle should add fuel to acc tank. Both FM Acc Slow & FM Acc Fast uses the Throttle Rate of Cange (ROC) as a parameter in the table.

Disturbances and small changes of the throttle causes by vibrations can easily start filling the acc tanks. To avoid this unwanted behavior, set two dead band rows in the table where no fuel is added.

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Example: Acceleration enrichment table with a dead band near 0 Throttle ROC.

To avoid the amount of fuel in the acc tank growing excessively there are max and min values the acc tank can’t exceed.

The variables Fm Acc XX Tank Max & Fm Acc XX Tank Max defines the acc tanks’ volumes.

Draining the tank

The Fast Acceleration Tank will be injected during the next two following rounds. If the label Fm Acc Fast Cylinder Max & Fm Acc Fast Cylinder Min is limiting the injected fuel mass the system will continue injecting during the following rounds until the tank is empty.

The Slow Acceleration Tank will be injected in a slower manner.

The table Fm Acc Slow Factor controls the amount of the slow tank to be injected. The Fm Acc Slow factor percentage value will control the injected slow mass based on the actual acc tank value. This continues until the tank is empty.

The injected fuel mass can’t exceed the Fm Acc Slow Cylinder Max & Fm Acc Slow Cylinder Min

Example:

From the table FM Acc Slow, 30mg of fuel have been added to Slow acc tank.

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The Fm Acc Slow Factor is mapped to 5%.

The extra amount of fuel to be injected next to rounds caused med slow acceleration enrichment will be:

30mg * 5% = 1,5 mg

The following two rounds

(30-1,5)mg * 5% = 28,5mg * 5% = 1,425 mg will be injected.

5.1.9 Mapping -> Engine Start

A number of tables are used for control the pre start, start and post start enrichment.

Start choke

Start Choke table is used for control the fuel during engine warm up.

0% = No Enrichment

20% = 20% More fuel

Post Start Enrichment

The maximum Post start enrichment is controlled in the table

Start Enrichment. The total enrichment for post start can never be greater than this value.

Start factor. The start factor is the percentage value of the start enrichment to be used. The start factor shall be ramped down to zero when the numbers of total revolutions increase.

The table Start Index has Time between start at one axis and start revolution at the other axis. The output is start index used in the table.

Start Primer

In the beginning of the start sequence, an additional fuel squirt is added. This additional fuel is injected as soon as NIRA i7x is synchronized. The appropriate amount of fuel depends on the engine temperature and is programmed in Start Primer Table. The amount of fuel is given in mg per cylinder and the Start Primer Table is independent from Start Sequence Enrichment Table.

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5.1.10 Mapping -> Ignition

Ignition timing table is default set up with MAP reading at it Y-axis. It’s possible to change the Y-axis of the ignition timing table by the label:

Mapping -> Ignition -> Flx Ign Angle Base Y

If Throttle based ignition angles are choosed, make sure the same axis is used in the Volumetric Efficiency Table.

For turbo or super charged engines a couple of preset tables are available in the Wizard. All provided preset tables should only be used for setting proper axis values and for start up purposes. Make sure that the ignition timing is correctly calibrated for your engine before putting load on the engine. Consult your NIRA i7x dealer for help with the calibration.

Ignition timing is an area of great interest and where a proper calibration can yield significant power improvements.

It’s very important, however, to make sure the ignition timing is correct since too much advance can cause significant damage at high loads. The damage occurs when premature detonation (or knock) happens. Knock is when the combustion happens too fast and the air-fuel mixture explodes instead of burning in a controlled fashion.

Knocking results in very high temperatures in the combustion chamber and it can sometimes chip the surface of the piston. More commonly, though, it can melt the edges of the piston.

You have to learn how to listen to your engine and hear knocking before you start modifying the ignition timing.

Advancing the timing increases the efficiency of the engine and lowers the fuel consumption and yields more engine power. You have to understand how boost pressure, compression, MAT, the gasoline octane rating, rpm, air/fuel mixture, load conditions etc. all effect the max ignition advance before you start modifying the timing.

You can check the ignition timing by entering the same value in the entire table. Choose a value around 20 degrees of advance. Then connect a timing light to cylinder 1 to verify that you see the correct advance at the crank pulley. Naturally, this requires that the pulley has the appropriate markings. Most engines run well with 20-30 degrees advance in the entire table up to 100 kPa MAP.

It’s beyond the scope of this manual to give any further advice on how to

calibrate ignition timing.

Ignition MAT Compensation

Engines are more knock resistant when the intake air is cooled down. Compensate the ignition for Manifold Air Temperature in this table.

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Negative value means retarded ignition

Positive values means advanced ignition

Ignition Flexiport Comp

Ignition Flexiport Comp is a totally user defined ignition compensation. The table is equipped with Nira FlexiportTM at both X- and Y-axis.

The table could be used four nitrous compensation or water injection compensation.

Negative value means retarded ignition

Positive values means advanced ignition

Ignition pin

NIRA i7x is equipped with 8 ignition outputs. The table Ignition Pin controls which output is used for a certain cylinder.

Note: This should be an Offline change. Do Not change due to the firing order in this table. Firing order is set up in “Bv Tdc Cylinder”.

One Coil per Cylinder (COP & CPP)

For sequential setup with up to 8 cylinder individual coils, one ignition output should be related to one coil.

Ignition Pin configuration for cylinder individual coils. One ignition output for each cylinder.

Waste fire Coil

It is possible to control a waste fire coil even though the injection is sequential.

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Ignition Pin setup for controlling a waste fire coil on a 4 cylinder engine

Distributor

If distributor is used, all ignition outputs should be set up to the same output.

Ignition pin setup for distributor set up

5.1.11 Mapping -> RPM Control -> RPM Limit

The rpm limit cuts out either injection or ignition to prevent over revving. For emission control injection cut outs are preferred.

 Engine Speed Limit is where the RPM limit starts to cut out injection or

ignition. The cut rate at Engine Speed limit is controlled in Es Limit Cut level Min

 Es Limit Cut Level Min is the cut rate that is used when enter Engine

speed limit

 Engine speed Limit Range When passing Engine Speed Limit +

Engine Speed Limit Range the cut rate is 100%. In the rpm range the cut rate is linearized between Es Limit Cut level Min and 100%

 Es Limit Cut Injection decides if injection or ignition should be cut out

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Engine Speed [rpm]

Cut out [%]

0 %

100 %

Engine Speed limit

Engine Speed limit range

ES Limit Cut Min

Explanation of the Engine Speed Limit

5.1.12 Mapping -> RPM Control -> RPM Control

The idle speed is calibrated by adjusting the parameters found in the “Air RPM” and “Ignition RPM” folders respectively. The parameters in the “Air RPM” folder are used for adjustment of an IAC valve or similar actuator that

controls the airflow. The parameters in the “Ignition RPM” folder are adjusted to enable a stable idle control by altering the ignition.

Fine-tuning of the idle speed is ideally done by altering the ignition since the technique of controlling air flow has inherent characteristics that makes it more suitable for rough adjustments.

5.1.13 Mapping -> AUX -> Input

Ten auxiliary inputs are available in NIRA i7x.

Aux Analog Input

Two analog inputs, typically used for ratiometric 0-5 V sensors such as additional pressure sensors can be utilized as auxiliary inputs. These are configured using the tables Bv Aux Ainput1 and Bv Aux Ainput2 respectively.

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Aux Temp

Six temperature inputs, typically used for NTC/PTC type temperature sensors can be utilized as auxiliary inputs. These are configured using Bv Aux TempX, where x is an integer between 1 and 6.

Aux Digital Input

Two inputs are available for detection of pulse signals, e.g. from wheel speed sensors. These are configured in Di Aux1 Teeth and Di Aux2 Teeth.

5.1.14 Mapping -> AUX -> Output -> Relay Control

NIRA i7x provides two fully customable relay controls.

Name

Controlled by

Comment

Related pin

Do Fan Relay

2D matrix with user defined axis

The output pin is active low

V55, Fan RLY

Do Aux Relay

2D matrix with user defined axis

The output pin is active low

V38, Aux RLY

Relay Control uses hysteresis. The Relay Control only switches when the matrix output is one or zero.

The red arrow shows direction of movement in Fan relay matrix when Coolant temp

increases

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To activate the relay output, the output from the matrix has to reach 1. In the example matrix above, the coolant temperature has to reach a temperature higher than 90 degrees Celsius to enable relay activation.

The red arrow shows direction of movement in Fan relay matrix when Coolant temp

decreases.

For deactivation the matrix has to reach an output equal to zero. In the example matrix above, the relay output will stay active until the temperature reaches a value lower than 80 degreases Celsius.

Between 80 and 90 degrees the output from the matrix will be in between one and zero and the output will not be affected.

Change the values in the matrix axis to achieve a more narrowband hysteresis.

DO Aux Relay

The matrix Do Aux Relay has user defined X- and Y-axis. It’s possible to choose between a wide range of values in NIRA i7x to tailoring your own control behavior.

The labels for axis control are:

 Flx Do Aux Relay X  Flx Do Aux Relay Y

5.1.15 Mapping -> AUX -> Output -> PWM Control

NIRA i7x provides three fully customable PWM controls with different characteristics.

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Name

Controlled by

Characteristics

Comment

Do Aux PWM1

3D matrix with user defined axis

6 amp for low speed inductive load

Low sider driver

E83, Aux PWM1

Do Aux PWM2

3D matrix with user defined axis

2 amp for low speed inductive load

Low sider driver

V90, Aux PWM2

Do Aux PWM3

3D matrix with user defined axis

2 amp for high speed inductive load

Low sider driver

V56, Aux PWM3

Do Aux PWM-x labels

All three Do Aux PWM-x is set up the same way.

 Do Aux PWM-x period

The period time of the PWM signal

 Do Aux PWM-x duty

A 3D matrix with the base duty

 Do Aux PWM-x duty out

The output from the matrix Do Aux PWM-x duty table is the input to this matrix. The Aux PWM-x duty out table handles non linear behavior of actuators.

 Flx Do Aux PWM-x duty X

User defined X-axis of the matrix

 Flx Do Aux PWM-x duty Y

User defined Y-axis of the matrix

 Flx Do Aux PWM-x duty Z

User defined Z-axis of the matrix

5.2 Going Online

When you have entered values for all parameters in Engine Setup you can connect your PC to NIRA i7x. Follow the steps below before you attempt to start the engine.

1. Turn on the ignition

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2. At the top of the main window in NIRA rk is the online/offline status

bar. In order to go online, click on the little green flash icon in the top left corner of the main window in NIRA rk. If the parameters in NIRA rk are different from the parameters previously uploaded to NIRA i7x, you will see the following dialogbox:

3. Select Update NIRA i7x in order to upload all the data to NIRA i7x.

This may take as long as two minutes.

Later you can select Read NIRA i7x if you want to download all the settings from NIRA i7x into NIRA rk so you can save them as an i3d file. (This is very handy if, for some reason, your PC were to hang while you’re in the middle of calibrating the engine since you can always go back and download the most recently used calibration.)

4. Once you have uploaded the data to NIRA i7x, the system goes

online, the status bar changes colors to green and the text changes to Online.

5. When the system is in the Online mode, it’s important to first go to the

Mappings tab and select the Monitor Output folder in the tree to the left and then select Alarm. Doing this allows NIRA i7x to detect

different errors and set alarms. If it doesn’t say OK next to all

parameters then the values in Engine Setup are wrong or the

sensor/actuator installation is wrong. Any alarm that’s viewable via the

Alarm folder is also displayed as large icons above the main tabs. These icons will disappear once the cause of the alarms has been corrected.

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6. Calibrate the Throttle Sensor such that the parameter reads 0% when

you take your foot off the gas pedal and 100% when you depress the

pedal fully. This can be done with the help of the “Accelerator Calibration Wizard” in NIRA rk. If you want to calibrate the Throttle

Sensor manually, follow the steps below.

Set NIRA rk to advanced mode.

Look for the labels.

Engine Setup -> All Paramters-> App Ad Pot 1 & App Ad Pot 2

Make a note of the parameter values for App Ad Pot 1 & App Ad Pot 2 when the gas pedal is fully depressed and when you let go of the pedal completely.

The notes should for App Ad Pot 1 & 2 for fully depressed throttle should be transferred to

Engine Setup -> Sensors-> App Pot 1 Umsp & App Pot 2 Umsp

Make the corresponding transfer from notes for fully released throttle. Enter the values in

Engine Setup -> Sensors-> App Pot 1 Umsp & App Pot 2 Umsp

Do Key Off & Key on.

Check Engine Setup -> All Paramters-> App Position

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Example. (Make sure the Throttle is fully closed before you start)

When the throttle is fully opened.

App Ad Pot 1 = 87,3%

App Ad Pot 2 = 0,1%

When the throttle position is fully closed.

App Ad Pot 1 = 7,4%

App Ad Pot 2 = 0,1%

Enter following values

App Pot 1 Umsp = 87,3%

App Pot 2 Umsp = 0,1%

App Pot 1 Lmsp = 7,4%

App Pot 2 Lmsp = 0,1%

Switch the key off and then on again and check.

Engine Setup -> All Paramters-> App Position

The value should go from 0% to 100 % when opening the throttle.

Now the throttle sensor is calibrated.

7. Go back to the Mappings tab, select the Monitor Output folder and

the ”General” subfolder. Make sure all sensors are calibrated correctly. If they are not, return to the Engine Setup tab, select the Sensors folder and correct the problem.

ECT and MAT sensor values should show ambient temp, or else they’re calibrated wrongly.

MAP should say approximately 100kPa, which is ambient pressure.

You can now start the engine. Select Toggle Dashboard under the Tools menu in the main menu, or hit the F7 key. Crank the engine. You should see the tach needle jump up to about 200 rpm or else the CKP sensor signal is missing and you won’t be able to start the engine.

Your engine should start fairly quickly and show reasonable values on the dash. If any instrument is showing an unreasonable value or if an Alarm icon appears, something is wrong in one of the parameters in Engine Setup, or the electrical installation is problematic.

Since the IAC hasn’t been calibrated yet, you may have to give a bit of gas in order to keep the engine from stalling.

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5.3 Quick Troubleshooting Guide

5.3.1 The Engine Won’t Start

Some of the more common causes are:

 Missing CKP sensor signal. Verify that the tachometer shows

approximately 200rpm when you crank the engine. If not, then the CKP sensor installation is the cause. Analysis of the CKP sensor signal is done using an oscilloscope

 Lack of fuel. Verify that the fuel pump is running. The pump should

run for about 2 seconds every time the ignition key is turned to the Key On Engine Off position (KOEO) position if the fuel pump and fuel pump relay are connected correctly. The pump also runs whenever the engine cranks and NIRA i7x sees a correct signal from the CKP sensor

 No current to the fuel injectors. Check that the injectors are getting

pulsed properly. If not, the electrical connections to the injectors are wrong or the injector setup in Engine Setup is wrong. Normal injector current is 0.8A for a 14 Ohm injector.

 DGE Camshaft alarm. If this alarm is set the CMP sensor signal is

wrong. Either the electrical connection is wrong or the setup in Engine Setup is wrong. (NIRA i7x may still be able to sync things correctly and start the engine approximately half the time.)

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 Wrong MAP. Verify that the MAP sensor reading is around 100kPa

(ambient pressure) when the starter isn’t turning. The MAP parameter is under “Mappings”-> Monitor Output -> 0.General -> Bv Manifold

Air Pressure. If you see a different pressure reading, the calibration is wrong or the sensor is damaged.

5.4 Other Adjustments

Since you were able to start the engine you are now ready to begin adjusting parameter values in order to improve engine performance. The next chapter includes lots of advice on how to do this.

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Mapping your Engine Using

NIRA rk

NIRA rk has two different modes; Standard and Advanced. The Standard mode is sufficient to achieve excellent mapping results. The Advanced mode gives access to a set of additional mapping parameters, which normally never need to be adjusted.

6.1 Tables

Don’t set up too many RPM columns on the x-axes in the beginning. Keeping the number low simplifies the calibration effort. It’s very easy to add columns later if you need greater resolution. The same is true for the y-axes.

You can eliminate the impact of any row or column by setting its value to an out-of-range value, e.g. 10,000 rpm or 0kPa.

The scale of the x and y axes is fully adjustable, which is a very powerful feature. This lets you increase resolution significantly in sensitive areas by adding more calibration points.

6.2 Calibrating Ignition

As described earlier, calibrating ignition is a delicate matter. A thorough

understanding of the engine’s allowed peak cylinder pressure, about knock

and about how ignition timing affects the combustion is crucial to achieve a good ignition calibration. Delving into these matters is beyond the scope of this handbook.

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6.2.1 Ignition at Idle

Ignition during engine idling is calibrated using the parameters available in the RPM Control  RPM Control  Ignition RPM folder.

6.3 Calibrating Fuel

NIRA i7x controls the amount of injected fuel based on two tables; Volumetric Efficiency Table (VE) and Fm Lambda Target. In NIRA rk, you find these tables in the Mappings tab under All Parameters -> 1.Fuel -> 1.Basic

Calibrate these tables by following the steps below.

6.3.1 Engine Start Fuel

For the engine to start, the correct amount of fuel has to be injected. The settings for start fuel are adjusted in the tables found under Engine Start  Injection control. How much extra fuel that is needed depends on a number of parameters and varies from engine to engine. Start with the default values and iterate changes until you are happy with the result.

In the beginning of the start sequence, an additional fuel squirt is added. This additional fuel is injected from all injectors at the same time, as soon as NIRA i7x detects crankshaft rotation. The appropriate amount of fuel depends on the engine temperature and is programmed in Start Primer table. The amount of fuel is given in mg per cylinder and the Start Primer table is independent from the values in the Choke Enrichment table and the other tables in the Engine Start folder.

6.3.2 Volumetric Efficiency Comp Table

This table sets up the compensation table for VE as a function of MAT.

When the MAT increases, the intake air volume expands, which in turn means the engine requires less fuel. Using the ideal-gas equation, we get

k=273/(MAT+273)

where the MAT is given in degrees Kelvin (K). 273K = 0°C.

When the fuel is injected and vaporized in the intake manifold, it cools the intake air, which increases VE. In addition, the cooling effect increases with MAT.

Based on experiments, a good approximation, when using gasoline, is the square root of k, which gives the final formula for VE compensation as: