dtec DYNertia3 User Manual
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DYNertia3 user manual
Manual version 8.1 (≥ V3.3.0)
DISCLAIMER: This software and hardware is provided "as is" without warranty of any kind, either express or implied, including, without limitation, any warranty of merchantability and fitness for a
particular purpose. In no event shall the creators of this software be liable for any direct, special, incidental or consequential damages arising out of the use or inability to use the software. The creators
and distributors of this software shall not be liable for any loss, damages or costs, arising out of, but not limited to, lost profits or revenue, loss of use of the software, loss of data or equipment, the costs
WARNING: This hardware and software is protected by law and international treaties. Unauthorized reproduction or distribution of DYNertia3, or any portion of it, may result in severe civil and criminal
of recovering software, data or equipment or claims by third parties, damage to equipment, or other similar costs.
For continuous product improvement and due to ongoing development, we reserve the right to alter specifications without notice.
penalties and will be prosecuted to the maximum extent possible under law.
DYNertia3 software is copyright- Ross Mclean 2017
DYNertia3 hardware & firmware is copyright- Darren Todd 2017
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DYNertia3 user manual
STOP !!!
Please read the appropriate ‘Quick Start’ guide for your dyno
type (Chassis or Engine & Inertia or Brake) first.
Actual testing is outlined there!!!
This ‘full’ manual contains much detail; by reading the ‘Quick Start’
guide first you will gain a basic understanding of the concepts and
key points required.
There are sample files installed along with DYNertia3 software so you can connect
the hardware and learn to use many of the features without needing to perform actual
tests. It is much easier to study without the noise of a screaming engine!
All examples in this manual use ‘Metric’ units such as kph/Kw/Nm etc. DYNertia3 can
be set in the software to ‘Imperial’ if you prefer mph/Hp/Ft Lb etc!
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DYNertia3 user manual
Table of Contents
Chapter 1: Introduction .............................................................................................................................. 10
Introduction .......................................................................................................................................................... 11
Features ................................................................................................................................................................ 12
Overview- ......................................................................................................................................................... 12
Analysing Test Results-.................................................................................................................................. 12
Data Acquisition- ............................................................................................................................................. 13
File Management- ............................................................................................................................................ 14
Printing- ............................................................................................................................................................ 14
Additional Functions- ..................................................................................................................................... 14
Load Control Options (EC and PC units)- ..................................................................................................... 15
Chapter 2: Hardware Installation ............................................................................................................... 16
Hardware Mounting .............................................................................................................................................. 17
Mounting the DYNertia3 Sensor and Magnet ............................................................................................... 17
Alternate Sensors to the supplied one ......................................................................................................... 18
Mounting the Electronic Control Unit ........................................................................................................... 19
Hardware Wiring ................................................................................................................................................... 20
Power supply connection ............................................................................................................................... 20
Example of typical wiring (additional devices shown) ................................................................................ 21
‘Linking’ Hardware to PC ..................................................................................................................................... 22
Chapter 3: ‘Brake’ Style Dyno Setup ......................................................................................................... 23
Brake (Absorber) Style Dyno Setup ................................................................................................................... 24
Basic concept .................................................................................................................................................. 24
Variations ......................................................................................................................................................... 25
Types of testing used with brake (retarder/absorber) style dyno’s ........................................................... 25
Load cell calibration and wiring for Brake type ........................................................................................... 25
Chapter 4: ‘Setup’ Menu Options .............................................................................................................. 26
Hardware- Setup Menu ........................................................................................................................................ 27
Brake / Inertia Button ................................................................................................................................ 27
Chassis / Engine Button ........................................................................................................................... 27
Inertia Mass Constants ............................................................................................................................. 27
Roller Circumference ................................................................................................................................ 27
Tire Circumference .................................................................................................................................... 27
Mass RPM Limit ......................................................................................................................................... 27
Sensor/Mass Ratio .................................................................................................................................... 28
Pulse Generator ......................................................................................................................................... 28
Tacho / Speedometer ................................................................................................................................ 28
OBDII Adapter input for Engine RPM and vehicle speed ...................................................................... 28
RPM Adapter input for Engine RPM ........................................................................................................ 28
Brake Inertia Correction (Only in ‘BRAKE’ mode) ................................................................................. 29
After Run Auto Braking/Vehicle Loading ................................................................................................ 29
Hardware Connections ............................................................................................................................. 30
Circumference Calculator ......................................................................................................................... 30
Moment Of Inertia Calculator ................................................................................................................... 30
Software- Setup Menu ......................................................................................................................................... 31
Graph Smoothness ......................................................................................................................................... 31
Point by Point (Open Loop Brake Mode) ................................................................................................ 31
Inertia Mode Graph Smoothness ............................................................................................................. 31
Passwords ....................................................................................................................................................... 31
Password (Program & Setup)................................................................................................................... 31
Lambda / AFR .................................................................................................................................................. 31
Preferred Lambda/AFR Channel .............................................................................................................. 31
Custom Fuel – Stoic/AFR and Name ....................................................................................................... 31
Graph ................................................................................................................................................................ 32
Auto Display of Last Run .......................................................................................................................... 32
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DYNertia3 user manual
Graph Torque Traces ................................................................................................................................ 32
Graph Trace ID’s ........................................................................................................................................ 32
Auto Shift Traces Right ............................................................................................................................ 32
RPM / Speed Scales .................................................................................................................................. 32
Power / Torque Scales .............................................................................................................................. 32
Run .................................................................................................................................................................... 32
Run Screens – Chart Reorders ................................................................................................................ 32
Run Duration .............................................................................................................................................. 32
Use Actual run Min RPM ........................................................................................................................... 32
Run Summary ............................................................................................................................................ 32
Live Slip Monitor ....................................................................................................................................... 32
Display .............................................................................................................................................................. 33
Multiple Monitor Support .......................................................................................................................... 33
Hide Windows Desktop ............................................................................................................................. 33
Data Window Transparency ..................................................................................................................... 33
Screensaver: .............................................................................................................................................. 33
About ................................................................................................................................................................ 33
Display of System Details ......................................................................................................................... 33
System .............................................................................................................................................................. 34
End of Each Run ........................................................................................................................................ 34
DYNO Correction Systems ....................................................................................................................... 34
Run D3 Snapshot ...................................................................................................................................... 34
Configuration Reset .................................................................................................................................. 34
General ............................................................................................................................................................. 35
Metric / Imperial ......................................................................................................................................... 35
Media (Audio) ............................................................................................................................................. 35
Remote ‘Page Turner’ Actions ................................................................................................................. 35
Data Consistency ...................................................................................................................................... 35
Point by Point (Brake Mode) .................................................................................................................... 36
Ratios................................................................................................................................................................ 37
Last Ratio Set ............................................................................................................................................ 37
Low Speed / RPM Operation .................................................................................................................... 37
Set Ratio- Change Increment ................................................................................................................... 37
Run Comments ................................................................................................................................................ 37
Comment Editing ....................................................................................................................................... 37
Comments added to each new Run ........................................................................................................ 37
Company Name ......................................................................................................................................... 37
Outputs ............................................................................................................................................................. 37
All Outputs (DYNertia3 and accessories) ............................................................................................... 37
Auxiliary Outputs (DYNertia3) .................................................................................................................. 37
File Storage Paths (Icon) ................................................................................................................................ 38
Set DYNertia3 base file storage path ...................................................................................................... 38
User Details (Icon) ........................................................................................................................................... 38
Set User Details ......................................................................................................................................... 38
Archive Storage Paths (Icon) ......................................................................................................................... 39
Set DYNertia3 archive storage path ........................................................................................................ 39
Load Control- Setup Menu .................................................................................................................................. 39
Communications- Setup Menu ........................................................................................................................... 40
Interface Port No. ...................................................................................................................................... 40
Link Button................................................................................................................................................. 40
Manual Set Button ..................................................................................................................................... 40
DYNertia3 ......................................................................................................................................................... 40
DYNertia Sensor Test ................................................................................................................................ 40
Weather Watch ................................................................................................................................................ 40
Update Interval .......................................................................................................................................... 40
Load Controller ................................................................................................................................................ 41
Torque Sensor ................................................................................................................................................. 41
OBDII................................................................................................................................................................. 41
Device Manager ............................................................................................................................................... 41
Open Windows Device Manager .............................................................................................................. 41
Printer .................................................................................................................................................................... 42
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DYNertia3 user manual
PRM/Speed Source .............................................................................................................................................. 42
Sensor Configuration .......................................................................................................................................... 42
Data Limits / Alarms ............................................................................................................................................. 42
Losses Systems ................................................................................................................................................... 42
Main Graph Trace Colour (Visible only from ‘Graph’ screen) ......................................................................... 42
Grid ........................................................................................................................................................................ 42
Operator ................................................................................................................................................................ 42
Chapter 5: RPM Input Options ................................................................................................................... 43
Engine RPM, Purpose and Options .................................................................................................................... 44
Why we may need engine RPM ...................................................................................................................... 44
Windows used for RPM setup (referred to in this chapter) ........................................................................ 44
RPM input Options (7 Available!) .................................................................................................................. 45
RPM Adapter input .......................................................................................................................................... 47
Summary of your RPM options ...................................................................................................................... 49
General RPM input information ..................................................................................................................... 49
Chapter 6: Overview- 2 Main Windows ..................................................................................................... 50
Two Main DYNertia3 Windows (DYNO / GRAPH) .............................................................................................. 51
DYNO Window ...................................................................................................................................................... 52
Record Settings ............................................................................................................................................... 52
Minimum Run RPM .................................................................................................................................... 52
Maximum Run RPM ................................................................................................................................... 52
Current Ratio.............................................................................................................................................. 52
Mode ........................................................................................................................................................... 53
Status .......................................................................................................................................................... 53
DYNertia3 Hardware Lamps (DYN) .......................................................................................................... 53
Run Control ...................................................................................................................................................... 54
Start Run Button ........................................................................................................................................ 54
Correction Factors .......................................................................................................................................... 55
User Comments Field ..................................................................................................................................... 55
Output controls and Status ............................................................................................................................ 55
Dial Gauge Displays ........................................................................................................................................ 56
Power & Torque dials ................................................................................................................................ 56
RPM/Speed dial ......................................................................................................................................... 56
Gauges Mode ................................................................................................................................................... 56
Data Gauges ON Button ........................................................................................................................... 56
Speed to RPM (ratio setting) .......................................................................................................................... 56
Strip Charts ................................................................................................................................................ 56
Data Dial Gauges ....................................................................................................................................... 56
GRAPH Window.................................................................................................................................................... 57
Tool Bar Button Functions ............................................................................................................................. 57
Exit .............................................................................................................................................................. 57
Print ............................................................................................................................................................ 57
RPM/Speed Mode ...................................................................................................................................... 57
GRAPH/DYNO ............................................................................................................................................ 57
Selecting Trace to Analyze ............................................................................................................................. 57
Selecting Trace to Display.............................................................................................................................. 57
Graph controls ................................................................................................................................................. 58
Data displays ................................................................................................................................................... 59
Run Time Gauges/Charts (Visible only from ‘DYNO’ Window) ....................................................................... 60
RPM and Speed Scales ................................................................................................................................... 60
Chapter 7: Weather Corrections ................................................................................................................ 61
Correction Factors .......................................................................................................................................... 62
Viewing Weather Data ..................................................................................................................................... 63
Chapter 8: Loading/Viewing Files.............................................................................................................. 64
Loading of files into ‘GRAPH’ Window .............................................................................................................. 65
Previewing (DYNertia3 File Explorer) and Selecting Files .......................................................................... 65
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DYNertia3 user manual
DYNertia3 file Explorer ................................................................................................................................... 66
Creating / Deleting folders for tests .............................................................................................................. 68
Reviewing Audio Files .................................................................................................................................... 69
Secondary GRAPH Window ................................................................................................................................ 70
Viewing Files (‘GRAPH’ Window) ....................................................................................................................... 71
Adjusting Graph appearance ......................................................................................................................... 71
Zooming ........................................................................................................................................................... 71
Clear Graph Trims ........................................................................................................................................... 71
Clear Graph ...................................................................................................................................................... 71
Trace Visibility ................................................................................................................................................. 71
Grid ................................................................................................................................................................... 71
Chapter 9: Trim, Merge & Join Runs ......................................................................................................... 72
Trim a Run ............................................................................................................................................................. 73
Merge Runs ........................................................................................................................................................... 74
Join Runs .............................................................................................................................................................. 75
Chapter 10: Test Notes- Add/Save ............................................................................................................ 76
Adding Test Notes................................................................................................................................................ 77
‘User’ comments field ..................................................................................................................................... 77
Accessing User Comments ...................................................................................................................... 77
Templates .............................................................................................................................................................. 78
Saving notes and applying to other tests ..................................................................................................... 78
Chapter 11: Printing & Exporting .............................................................................................................. 79
Printing .................................................................................................................................................................. 80
General Printing .............................................................................................................................................. 80
Print ............................................................................................................................................................ 80
Setup Printer .............................................................................................................................................. 80
Offset Correction ....................................................................................................................................... 80
Printing main Graph screens ......................................................................................................................... 81
Dyno Operator ........................................................................................................................................... 81
Information for Printed Output................................................................................................................. 81
Print ............................................................................................................................................................ 81
Select Page ................................................................................................................................................ 81
Customising your printout ............................................................................................................................. 82
User Details and Company Logo ............................................................................................................. 82
Customer Disclaimer ................................................................................................................................ 82
Notes to print ........................................................................................................................................................ 83
General comments for printing ...................................................................................................................... 83
Produce comments on the main graph for printing .................................................................................... 83
Exporting data ...................................................................................................................................................... 84
Select a Trace to export ............................................................................................................................ 84
Chapter 12: Live Data Viewing ................................................................................................................... 85
Gauge Screens ..................................................................................................................................................... 86
Observing the engine data ............................................................................................................................. 86
Observing the Data Channels ............................................................................................................................. 88
Display Current AFR/Lambda ............................................................................................................................. 89
Chapter 13: Analysing Data (‘View’ Menu) ................................................................................................ 90
Trace Info .............................................................................................................................................................. 91
Secondary Graph ................................................................................................................................................. 91
Individual Trace Set ............................................................................................................................................. 92
Compare ................................................................................................................................................................ 93
Torque Analysis ................................................................................................................................................... 94
Losses ................................................................................................................................................................... 95
Lambda / AFR Deviation ...................................................................................................................................... 96
Distance / Speed / Time / RPM Analysis ............................................................................................................ 97
Slip / Tyre Growth................................................................................................................................................. 98
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DYNertia3 user manual
Run Duration Info ................................................................................................................................................. 99
Point to Point Times .......................................................................................................................................... 100
XY Graph ............................................................................................................................................................. 101
Run Data vs Time ............................................................................................................................................... 102
Chapter 14: Inputs- Using ........................................................................................................................ 103
Pin Allocations ................................................................................................................................................... 104
General Input Notes ........................................................................................................................................... 105
Important general information ..................................................................................................................... 105
Wiring inputs for best results ...................................................................................................................... 105
Connecting Sensors .......................................................................................................................................... 106
General sensor connection (0-5V input shown) ........................................................................................ 106
Resistive sensor connection ....................................................................................................................... 107
Connection of DTec’s ‘Thermo-Amp’ thermocouple amplifier (for K-type sensors) ............................. 107
Air/fuel ratio meter connection (DTec ‘WB2’ unit as example)................................................................. 108
Connection of load cell for brake (absorber) style dyno’s ....................................................................... 108
RPM Adapter Input ............................................................................................................................................. 109
General notes on wiring the RPM adapter input (secondary way of measuring RPM) .......................... 109
Using a DTec ‘RPM adapter’ for the RPM adapter input ........................................................................... 109
Basic connections for a DTec ‘RPM adapter’ to DYNertia3’s RPM Adapter input ................................. 110
Connections for a DTec ‘RPM adapter’ to suit spark plug wire sensing ................................................. 110
Connections for a DTec ‘RPM adapter’ to suit coil ‘switching’ signals .................................................. 110
Connections for a DTec ‘RPM adapter’ to suit coil ‘drive’ signals .......................................................... 111
Connections for a DTec ‘RPM adapter’ to suit ‘VR’ (inductive) sensors ................................................. 111
Sensor Configuration ........................................................................................................................................ 112
Configuring an input channel using pre-settings ...................................................................................... 112
Creating your own linear (2 points, straight line) sensor calibrations .................................................... 113
Naming and calibrating of Lambda / AFR meter inputs ............................................................................ 114
Creating your own non-linear sensor calibrations .................................................................................... 114
Testing sensor configurations ..................................................................................................................... 116
Getting the best data ..................................................................................................................................... 117
Channel Filtering ..................................................................................................................................... 117
Reference Voltage Correction ................................................................................................................ 117
Sensor Alarm Points .......................................................................................................................................... 118
Sensor On / Off (Recording) .............................................................................................................................. 118
Data Consistency ............................................................................................................................................... 119
Chapter 15: Outputs- Using ..................................................................................................................... 120
Auxiliary Connections ....................................................................................................................................... 121
Connecting outputs if required .................................................................................................................... 121
Output functions ........................................................................................................................................... 121
‘Run’ Output ............................................................................................................................................. 121
‘User’ Output ............................................................................................................................................ 121
‘Brake’ Output .......................................................................................................................................... 122
Chapter 16: Load Controllers .................................................................................................................. 123
Hardware Mounting & Basic Wiring ................................................................................................................. 124
Mounting the speed sensor................................................................................. Error! Bookmark not defined.
Mounting electrical components ........................................................................ Error! Bookmark not defined.
Eddy Current Load Controller Wiring .............................................................................................................. 125
Eddy controller wiring (basic- no accessories) ......................................................................................... 125
Eddy current controller wiring harness connections ................................................................................ 126
PWM Current Load Controller Wiring .............................................................................................................. 127
Wiring PWM controller wiring (basic- no accessories) ............................................................................. 127
PWM current controller wiring harness connections ................................................................................ 128
Load Cell Connection ........................................................................................................................................ 129
Wiring of the load cell (including pressure sensor style) ......................................................................... 129
Load Cell Setup & Calibration ........................................................................................................................... 130
Sensor Calibration ........................................................................................................................................ 130
Manual Sensor Calibration ........................................................................................................................... 132
Automatic Sensor Drift Cancellation ........................................................................................................... 132
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DYNertia3 user manual
Brake ‘Closed Loop’ PID Tuning ...................................................................................................................... 133
Load control system commissioning .......................................................................................................... 133
Load Unit- Current Limitation ................................................................................................................ 133
Load Control Output ............................................................................................................................... 133
Throttle Servo Speed .............................................................................................................................. 133
Sudden RPM/Speed Drop Warning ....................................................................................................... 134
PID Test Settings ..................................................................................................................................... 134
Setup procedure ...................................................................................................................................... 135
Proportional value ................................................................................................................................... 135
Integral value ........................................................................................................................................... 135
Derivative value ....................................................................................................................................... 135
Upload Settings ....................................................................................................................................... 136
Saving and Loading Configurations ..................................................................................................... 136
Last Runs PID Power .............................................................................................................................. 136
PID Settings History ................................................................................................................................ 136
Over Temperature Load Thermostat ..................................................................................................... 136
‘Closed Loop’ Windows ..................................................................................................................................... 137
Load control window .................................................................................................................................... 137
Manual testing load control.......................................................................................................................... 137
Manual Load Control ............................................................................................................................... 137
Manual Target Fast Setting .................................................................................................................... 137
Ramp testing load control ............................................................................................................................ 138
Ramp Load Control ................................................................................................................................. 138
Ramp Mode Editor ................................................................................................................................... 138
Saving and Loading Timelines............................................................................................................... 138
Step testing load control .............................................................................................................................. 139
Step Load Control ................................................................................................................................... 139
Step Mode Editor ..................................................................................................................................... 139
Saving and Loading Timelines............................................................................................................... 139
User testing load control .............................................................................................................................. 140
User Load Control ................................................................................................................................... 140
User Mode Editor ..................................................................................................................................... 140
Saving and Loading Timelines............................................................................................................... 140
Run Options, Files and Information ............................................................................................................ 141
Timeline Preview and Selection ............................................................................................................. 141
Throttle Trims .......................................................................................................................................... 141
Manual Min RPM ...................................................................................................................................... 141
Manual Mode Load Response ................................................................................................................ 142
Load Control Keyboard Steps................................................................................................................ 142
Run Min/Max ............................................................................................................................................ 142
Auxiliary Outputs .................................................................................................................................... 142
Run Throttle ............................................................................................................................................. 142
Record Run .............................................................................................................................................. 142
Load Controller Auxiliary Options.................................................................................................................... 143
Expansion port overview .............................................................................................................................. 143
Expansion port connection details ............................................................................................................. 143
Expansion port functions ............................................................................................................................. 144
Throttle Output ........................................................................................................................................ 144
Throttle Input ........................................................................................................................................... 144
Auxiliary Outputs 1 and 2 ....................................................................................................................... 145
Over Temperature Alarm Input .............................................................................................................. 145
Chapter 17: Losses Correction ................................................................................................................ 146
’Losses’ System ................................................................................................................................................. 147
What are the effects of Mechanical Losses?.............................................................................................. 147
What does Measured Mechanical Loss Correction do? ........................................................................... 147
Are these “Losses” worth worrying about? ............................................................................................... 147
Configuration Window .................................................................................................................................. 148
USER ESTIMATED Mechanical Loss Correction ....................................................................................... 150
MEASURED Mechanical Loss Correction ................................................................................................... 151
General setup for DYNO Loss testing ......................................................................................................... 152
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How often should I run DYNO losses correction? ..................................................................................... 152
Observing effect of Losses Correction ....................................................................................................... 153
Chapter 18: Maths Channels .................................................................................................................... 154
Concept .......................................................................................................................................................... 155
Sample expressions, simple ........................................................................................................................ 157
Testing an expression .................................................................................................................................. 157
Variables in detail .......................................................................................................................................... 157
Creating and saving a math’s expression .................................................................................................. 158
Applying an expression to a dyno file ........................................................................................................ 158
‘Exception’ notifications ............................................................................................................................... 159
Chapter 19: ‘Utilities’ Menu ...................................................................................................................... 160
Send an email ................................................................................................................................................ 161
Lambda AFR Converter ....................................................................................................................... 161
RPM / Torque / Power Calculator ................................................................................................................. 162
Metric / Imperial convertor for Torque / Power .......................................................................................... 162
Display current Weather Data ...................................................................................................................... 162
Display Current AFR/Lambda ...................................................................................................................... 163
RPM/Speed Stability ...................................................................................................................................... 163
Data Diagnostics ........................................................................................................................................... 164
Chapter 20: Trouble Shooting & FAQ’s................................................................................................... 165
Trouble Shooting- Common Issues ................................................................................................................. 166
Frequently Asked Questions (FAQ’s) .............................................................................................................. 169
Chapter 21: Specifications ....................................................................................................................... 170
Specifications ..................................................................................................................................................... 171
Notes ................................................................................................................................................................... 172
Chapter 22: Additions & Changes ........................................................................................................... 173
Software V3.4.x Changes & Errata ................................................................................................................... 174
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Chapter 1: Introduction
Chapter 1: Introduction
Overview and features!
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Chapter 1: Introduction
Introduction
The DYNertia3 Dynamometer package allows for simple and inexpensive "Do It Yourself" construction / upgrade of an
Inertia or Brake Dyno.
Perfect for any one interested in engine / vehicle tuning, testing and modification whether it be car, bike or even model
sized engines.
For those requiring ‘Closed Loop’ Brake control, please refer to our chapter on the optional ‘Load Controller’ systems,
this is an additional unit that interfaces to the DYNertia3 box.
An Inertia type Dyno operates on the principle of calculating the Power required to accelerate a known mass, which is
simply an additional 'flywheel' coupled to the engine or vehicle. The controller senses the velocity of the rotating mass
and outputs this and other data to the DYNertia3 software. No expensive Load Cell is required and repeatability is
excellent.
Brake type Dyno’s use an absorber system (Hydraulic, Friction, Eddy Current etc) to load the engine and the resultant
Torque is measured by a ‘Load Cell’. In ‘Brake’ mode DYNertia3 uses this Torque input and RPM to calculate Power.
The DYNertia3 software package handles all of the functions required for Dyno control: configuration, saving Runs,
correcting for atmospheric conditions, filtering, displaying data, printing, overlaying and analyzing multiple Runs.
A rotation sensor is included with the DYNertia3 Controller; you simply attach a magnet (supplied) to the Inertial Mass /
Brake or drive system. Optionally, we can supply a Hall sensor designed to sense a metal ‘target’ rather than a
magnet, allowing a metal protrusion or tooth to be used as the Sensor "target".
The closed loop Load Controller systems use an alternative sensor system (sensor is still provided by us) as it is
triggered by a target wheel with multiple teeth.
For Engine or Chassis Inertia Dyno's we also provide a comprehensive guide to assist in the design and construction of
the Inertia Assembly. All you need in addition to this is the DYNerta3 package and a PC with a USB port.
Five analogue data channels and one digital input (secondary RPM input) are available for displayed and recording these are completely flexible and can be used for sensors such as Air Fuel ratio, Exhaust Temperature, Pressure, Load
Cell, secondary RPM etc. Two ‘Math’s’ channels can be created from any of the existing data (create your own
formulas), just think of the tuning possibilities!
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Chapter 1: Introduction
Features
Overview-
Suitable for chassis and engine dyno designs, either direct or indirect drive to the inertia flywheel. Power measurement
can also be taken from a ‘load cell’ for use on brake style dynos (e.g. water, eddy current, hydraulic, friction). DYNertia3
does not control the actual load on a brake style dyno, the load must be controlled manually (i.e. it’s not closed loop).
For closed loop control of a load please see our optional ‘Load controller’ unit and related chapter.
Software provided handles all data management, analyzing and graphing required for your dyno project with powerful
features yet a ‘clean’ interface. Both Metric and Imperial modes are provided, Power, Torque and setup parameters are
changed from kph/Kw/Nm/ºC to mph/Hp/Ft Lb/ ºF etc.
Comprehensive Manual provided, also design & construction information is available for the mechanical dyno system,
including an Excel spread sheet to assist with choosing and calculating the moment of inertia for your requirements.
Included magnetic sensor (hall effect) has an indicator for diagnostics. Integrated ‘optical isolation’ circuitry in the data
acquisition systems helps limit ignition interference and provides PC protection.
As an inertia dyno, accuracy is only limited by mechanical system variation, internally each rotation is timed to 1μs (1
millionth of a second). Dual microprocessors share the data acquisition and precision timing tasks.
Ideal for portable applications (track days & exhibitions). Power supply can be from a simple 12VDC battery, 7 to18VDC
is required, e.g. a cordless drill or bike battery is ideal! We recommend a battery as resistance to interference and data
acquisition signals is far better than with a ‘plug pack’!
Compact, approximately 110L x 83W x 45H (mm) with a small remote sensor for easy adaptation to your design.
No ignition system adapters are needed for RPM sensing. It can determine engine RPM from shaft RPM by ‘learning’
their relationship (ratio). Up to 8 gears can be learnt and later selected for quick testing in any gear; the ratio can also be
manually entered if no tachometer, simply based on number of sprocket teeth (e.g. for chain drive kart engine dynos).
If an engine RPM input (not otherwise required) from the engine is available, then this can not only be used as engine
RPM but also means the difference between engine and shaft/flywheel RPM can be plotted to show clutch engagement
RPM or reveal wheel slip on a chassis dyno.
Inertia value for up to 3 Inertia mass flywheels can be stored and easily selected for designs with adjustable Inertia mass
to tailor to engine characteristics.
Compensation for Dyno Inertia during ‘brake’ testing is easily applied. Great if you have an inertia dyno, but wish to add
an additional load (brake/retarder) for ‘running in’ engines or ‘steady state’ testing.
Analysing Test Results-
Supports multiple monitors, if a second monitor is available then key Windows can be viewed separately to allow clear
analysis, even if viewing and comparing many test results.
Overlay up to 10 Power and Torque graphs simultaneously, including the ‘Last Run’ which automatically appears after
your Run is completed. Run trace color sets are user selectable, however ‘Last Run’ always graphed in red for quick
identification.
Analyse and compare test results by easily ‘hiding’ any particular Run trace or quickly replacing with other saved Runs
for comparison.
A reference Run trace can be locked so that it always stays on the screen for comparisons against other tests.
Up to 4 sets of Runs can be merged to create a brand new 'averaged' Run. Perfect for getting the most from
analysis. The new generated file appears just like any other in DYNertia3. Comments are automatically attached that
reveal the individual runs that it was generated from for future reference.
All 5 analogue channels are recorded with each Run for analysis and their value at the cursor are shown in a floating
'data box' (which can also be saved to ‘clipboard’). DYNertia3 can overlay 2 chosen data channels with the existing
Power and Torque traces for display or all of the data for any trace can be shown in a separate single Window for
detailed analysis.
Select a graph trace; an onscreen cursor makes the dials (power, torque and RPM/speed) display exactly what was
happening at that point in the test Run.
Advanced torque analysis is provided to graphically display ‘area under the curve’ and related statistics for comparing
multiple traces.
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Chapter 1: Introduction
Analysing Test Results (cont.)-
The percentage difference between a reference trace and the remaining traces can be shown graphically, for all data.
Instantly see where each modification either improves or degrades performance compared to other runs. Great tool!
Lambda / AFR deviation is shown in a special Window that allows you to set a target value, it shows you where and by
how much the real test results varied (essential for quick mixture tuning). Obviously an AFR meter must be connected!
Select any RPM/speed points and the time between them is shown for all Runs (up to 10), clearly reveals ‘real world’
acceleration improvements after modifications. Best performing Runs between all points are highlighted.
Full data table display of ‘point by point’ Power, Torque, RPM and Speed are produced for detailed study and can be
exported directly into Microsoft Excel (with field headings included) or a text file (comma delimited ASCII, CSV.) can be
generated, even the main graph view can be exported as a bitmap image (‘.bmp’) for further analysis and file sharing.
The relationship between distance traveled, time elapsed, Speed and RPM can be studied in a graphical analysis
screen.
XY graph, choose any data to plot against another and display values at the cursor.
Math’s ‘Expressions’ (formula) can be applied to any existing data to generate an additional 2 data channels. A powerful
tool is provided to easily write, test and apply your concepts.
Click on the Run of interest to show all the data that relates to it. The test conditions, max readings, set up details or any
of your personal notes that are saved along with each run can all be reviewed.
Full manual ‘zoom’ available on Power, Torque and RPM displays to display selected graph regions of interest.
Runs can be ‘trimmed’, the lower and upper speed section of graphs can removed if visually required (e.g. if tests start
and finish RPM were inappropriately set) and the Run re-saved.
User selectable ‘Trace Shift’, the last 10 trace sets are always displayed (each new test trace ‘shifts’ the oldest one out
of selection) - great when performing comparisons.
‘Auto Load’ your graph after a Run – can be selected to automatically switch to the graph display after each test Run or
you can opt to do as many Runs as you like in quick succession and analyse as a graph later. A brief test summary is
also immediately available after each test Run is completed.
Onscreen graph legend to rapidly identify Run trace set colors and filenames and a run summary is available to give the
key data for all the selected runs in one concise table.
Data corrected for weather conditions with world standards (SAEJ607, SAEJ1349, DIN70020 or uncorrected). The
environmental conditions and resultant correction factor are stored with each Run. Data can be manually entered or
‘Weather Watch’, automatic updating weather station is available as an option (USB to PC).
Data Acquisition-
Data acquisition of 5 analogue input voltages is incorporated (‘common’ ground). This allows the monitoring of variables
such as air fuel ratio, exhaust temperature etc.
Inputs can be 0-5V or 0-15V (each channel has a range selection switch)
Resistive sensors, such as standard automotive temperature sensors, can be easily connected as each channel has a
selection switch that enables an internal ‘pull up’ resistor (just connect the sensors 2 wires directly to DYNertia3!).
A data logging function is provided allowing the 5 input channels (plus the digital RPM input) to be logged to the PC. The
logging rate can be set and the data is saved (with field headings included) as a text file (.CSV) for later analysis in
Microsoft Excel etc.
Input data can be viewed separately (can even be displayed on separate screen if dual monitors used) or is available
whilst performing testing. Minimum and maximum alarms can be set to alert if sensors detect anything outside an
acceptable level (lean mixtures, engine temperature overheat or oil pressure loss as examples).
The input channels are fully scalable, even for non-linear sensors. Many sensor choices are already pre-calibrated and
DYNertia3 software doesn't just display the input voltage measured, a table for each input allows it to be calibrated and
displayed in any units you choose (eg Lambda, air/fuel ratio, degrees, PSI etc).
For configuring non-linear sensors, such as automotive style temperature sensors, there is a tool provided that just
requires 3 test points to be entered and it creates a full calibration table.
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Chapter 1: Introduction
Data Acquisition (cont.)-
Simple screw type terminals on a removable terminal plug allow for quick and easy sensor wiring. Both a 5 Volt and 12
Volt output to power auxiliary sensors is also present if required.
An additional digital channel is provided if you wish to have engine RPM directly measured (via a Hall sensor or DTec’s
‘RPM adapter’). This option can help reveal tyre slip/growth on a chassis dyno or centrifugal clutch engagement RPM.
There is a dedicated analysis screen to examine slip/tyre growth.
File Management-
Designed to perform testing quickly- common user settings are saved to reduce set up times and any personal notes
you’ve entered in the provided form (general, vehicle, owner details etc) can be saved as a ‘template’ and applied to
other runs to save re-entering the details, even copies the Run’s set up details. Files can also be set to ‘auto name’, the
file name simply increments with each test (and can carry over any personal notes), no need to even re-enter a name.
Advanced previewing function (‘DYNertia3 File Explorer’) shows graphs, summary details and the data table of all saved
runs, this allows quick selection for loading into the main graph screen or for file management purposes. A cursor is
even available to highlight points of interest on the graph and indicate that same location in the data table- no more
browsing through cryptic file names!
User configurable directories- have as many separate directories to store your runs in as required and file protection can
be applied to prevent individual files from being accidentally changed or overwritten if required.
Printing-
Color print outs of your chosen graph or overlaid graphs (up to 5 printed on same graph) is only a mouse click away,
complete with preview. A report page is also generated that has a summary of all the important test conditions, max
readings, date, time, company logo, graph notes etc.
Printouts includes Run trace sets legends, colors and filenames, the graphs ‘grid lines’ can even be turned off!
Comments can be placed on the graphs to appear on the printouts.
Printing of specific areas of interest can be performed using the manual ‘zoom’ function.
Additional Functions-
‘Point by Point’ testing mode for brake style dyno’s allows recording of individual data points at the press of a button.
These individual data sets are then combined to construct a conventional Run trace for easy analysis and comparisons.
For dyno competition entertainment, after a run maximum Power and Torque can be displayed in large format for crowds
to easily see (result in both imperial and metric units).
Graphs are fully auto-scaled, Power, Torque and RPM scales are automatically configured for optimal display.
Flexible options for performing a test; a Run can be from ‘start’ command to ‘stop’ command or from ‘start’ command to
zero power. A minimum speed can also be specified and data below this will be discarded, this eliminates any different
start points of tests due to operator error.
All dial gauges have digital displays incorporated.
Gauges display ‘real time’ data during monitoring or setup. Ideal for steady state tuning with a brake type dyno! (only
RPM is displayed 'real time' in Inertia mode)
Data ‘Smoothing’ that is applied to the Power traces is adjustable to ensure you don’t miss out any detail but still end up
with optimal appearing graphs.
There is a “Losses” function that can be used to measure and apply a correction to data for mechanical losses in your
dyno system like friction and windage (typically very small) even or/and for driveline losses due to friction.
DYNertia3 is fully isolated (optically) from the PC, this helps prevent any damage to the PC from incorrect connections
(power DYNertia3 from a battery source for this full isolation!). DYNertia3 is also protected from reversed polarity supply
connection.
A ‘system in motion’ (“Run”) output is available that is active as long as the flywheel is rotating, or a function is used that
may result in rotation. This can directly control a relay to operate safety control systems/warnings if required or for
automatic fan controls etc.
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Chapter 1: Introduction
Additional Functions (cont.)-
An ‘Auto Brake’ output is available that can directly operate a relay for an automatic brake for slowing the flywheel down
if you wish, or an automatic cooling fan for cooling friction style brakes. The time it’s active for after a test Run is
adjustable in the software. The output can alternatively be operated manually in the software and will be active for either
a short time or continuously.
A ‘user controlled’ output is available can directly operate a relay, it is manually turned on or off from the software and
can be used for any general purpose function e.g. remotely turning on a cooling fan, pumps wheel clamps etc.
Tools to work out the moment of inertia of your dyno system, calibrate non linear sensors, convert air:fuel ratios to
Lambda and for analysing relationships between Power / Torque / RPM are incorporated.
Keyboard ‘shortcuts’ assist with easy operation and an inexpensive and commercially available wireless keyboard or
even a remote ‘page turner’ (the device often seen used for PowerPoint presentations) can be used as a remote control
that can start/stop Runs, turn the gauges on/off and allow automatic file incrementing (no need to type in a new name).
Very convenient if operating both the vehicle and the dyno single handedly.
Load Control Options (EC and PC units)-
For controlling a brake type dyno in ‘closed loop’ mode we have available additional modules that connect into the
DYNertia3 unit.
There is an Eddy current power supply unit that provides the high voltage DC required by the eddy brake (retarder) and
also available is a unit with PWM output for alternative dyno types.
The load control option allows full closed loop control of the dyno. You can set a target RPM/speed to maintain it or
perform ramp and step testing.
Control of an electronic throttle servo is also possible with either load controller option. The ‘servo pulse’ output can be
used with conventional servo motors and allows integration of the throttle for either manual control or integrated into the
test procedure.
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Chapter 2: Hardware Installation
Chapter 2: Hardware Installation
Hardware mounting
Alternate sensor options
Basic power wiring (see ‘Inputs- Using’ chapter for full details)
‘Linking’ hardware to the software
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Chapter 2: Hardware Installation
Hardware Mounting
Mounting the DYNertia3 Sensor and Magnet
NOTE: When DYNertia3 is used with the optional ‘Load Controller’ (for ‘closed loop’ dyno) the sensor type and
mounting procedure shown below is not relevant, please see the ‘Load controller’ chapter for details.
DYNertia3 times the rotational period of a component by sensing its position magnetically. The included sensors ‘face’
contains a magnet sensing ‘Hall Effect’ switch. The sensor detects the position of the magnet attached to the rotating
dyno flywheel/load brake/shaft and processes to trigger the timing procedure.
NOTE: The rotation sensor system is the main RPM input used by DYNertia3 for Power calculation and therefore must
always be setup for operation. If you choose to also use the engine ignition system (or other source) as a secondary
RPM input then please read the chapter on ‘RPM Input Options’ in this manual regarding this optional input!
A small (9mm x 1.5mm with 3mm mounting hole) but very powerful ‘rare earth’ magnet is included with the kit. The
magnet is small as this reduces the forces involved when rotating so it is easier to secure safely.
Do not mount the magnet at the perimeter of the dyno flywheel/shaft/sprocket etc. as the centrifugal forces will be
highest; choose a location towards the centre area. The magnet is also very fragile and must be handled with care!
NOTE: The included sensor will only detect the ‘South’ Pole of a magnet, so the magnet must be have the South Pole
(marked with red paint) facing the sensor!!
Mounting by screwing/gluing flat to dyno flywheel-
Dyno flywheel is drilled and tapped for 3mm screw (2.5mm drill size is
usual for 3mm tapping). Short (min 6mm) screw inserted into magnet.
Do not over tighten or magnet may crack!
Magnet epoxy glued and screwed to dyno flywheel with South Pole outwards.
The sensor face must be positioned 1.5 - 2mm from the
magnets South Pole (or the head of the screw if one is used
to secure magnet).
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Chapter 2: Hardware Installation
Hardware Mounting (cont.)
A16mm diameter hole is required to mount the sensor. Do not over tighten the lock nuts or they will be damaged. A
small ‘blob’ of silicon sealant or similar is applied to the edge of the nuts to stop them loosening with vibration.
Tip- After the ‘Linking’ process (discussed
later) the sensor operation can be checked
via the button “DYNertia3 Sensor Test”. The
indicator and an audible noise can be used
to confirm sensor operation during rotation.
The indicator lamp/noise triggers for a short
time as the magnet approaches the sensor
(only on approach).
KEY POINTS- 1.5 – 2mm gap. Safe magnet mounting, South Pole (marked with red
paint) of magnet facing towards the sensor!
Alternate Sensors to the supplied one
DYNertia3 can accept other types of sensors if you prefer. The sensor input terminal is a digital input; it will not accept
voltage from an inductive sensor (VR). The ‘signal’ terminal of DYNertia3 needs to be ‘pulled’ to ground when a target
object is detected. Sensors that switch to ground like this are called ‘open collector’ style and include most industrial
proximity sensors (too slow generally) and also the majority of automotive camshaft sensors (‘Hall’ type).
NOTE: If you are unsure please just contact us for help; we are not responsible if you damage the unit from incorrect
connection!
Hall sensors- Hall sensors are ‘switching’ style sensors and are compatible, they are available to detect either magnet
or metal ‘target’ objects. This may be a good choice if you wish to detect a rotating metal object rather than a magnet
like the provided sensor does i.e. perhaps you have a protruding ‘key’ in a shafts key way. A common metal sensing
sensor example (shown below) is the ‘Honeywell 1GT101DC’ sensor or most automotive camshaft sensors are good.
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Chapter 2: Hardware Installation
Hardware Mounting (cont.)
Mounting the Electronic Control Unit
Strong vibration may also destroy the sensor and control unit (as with all electronics) so it is important to consider
mounting arrangements carefully.
NOTE: Engines with CDI ignitions, especially in conjunction with copper core spark plug leads and non-resistive spark
plugs can generate large electrical interference for all electronics including PC’s. It is very important to apply the
following mounting and cable routing suggestions to avoid any problems!
It is very important to keep the PC, DYNertia3 and it’s cabling well away from large sources such as ignition systems-
1) Mount the sensor unit at the furthest distance (‘every inch counts’!) from the engine as possible. Route all cables
as far as possible away from the engine (and any electric motors such as cooling fans) and keep the controller and PC
at a distance. Coil any spare cable up neatly at the PC. Keep the sensors lead away from the USB lead or any other
wiring.
It’s best to route cables inside a protective metal tubing or keep separated from the engine by mounting behind the
earthed metal of the dyno frame or shields. Secure at the DYNertia3 control unit to prevent movement of the cables.
DYNertia3 software can even be operated by remote control if required (wireless keyboard or a PC ‘page turner’ as one
option), tests can be started and stopped and new files even created (names incremented).
2) Always use resistive Spark plugs and suppressed Spark plug leads to prevent interference (at least during testing).
Tip- A suppressed spark plug lead from a car can be put in series with the existing spark plug to reduce interference.
This additional spark lead is essential on many go-kart engines as they have particularly ‘noisy’ ignition systems!
3) Follow the wiring advice in the “Inputs- Using” chapter on wiring if measuring from additional sensors.
Secure any leads close to the DYNertia3 control box. The aim is so that the leads are
completely prevented from movement, as this will place stress on the connectors and
wiring.
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Chapter 2: Hardware Installation
Hardware Wiring
Power supply connection
Please see chapter called ‘Inputs- Using’ of this manual for full wiring details on connection of data acquisition devices,
below we just cover the power supply connection required for basic operation.
Power supply can be from a simple 12VDC battery, 7 to 18VDC required. DYNertia3 typically draws less than 50mA so
very little demand is put on a battery e.g. a cordless drill or bike battery is ideal!.
A power pack connected to mains is NOT recommended, especially if data acquisition is being used. The resistance to
interference and stability of the data acquisition signals is generally much better with a battery! This is very dependant
on the dyno installation, PC used and engine types being tested (as to how much interference they produce). If using a
power supply it should be fully regulated (not just a battery charger!) and be trailed to ensure it is acceptable.
Full isolation protection (optical) for the PC is only provided when DYNertia3 is powered from a battery source.
NOTE: Very low battery voltage (less than 7VDC) will cause poor sensor operation and erratic results. Please monitor!
With power connected to DYNertia3 the status LED (next to the sensor connector) will blink twice at first to indicate
microprocessor is initialising. After this the LED will illuminate to indicate power, but don’t assume there is not a power
supply problem based solely on LED operation, it takes very little voltage to light an LED!
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Chapter 2: Hardware Installation
Hardware Wiring (cont.)
Example of typical wiring (additional devices shown)
Please see chapter called ‘Inputs- Using’ of this manual for full wiring details on connection of data acquisition devices.
For brake type dyno’s there will be a load cell and amplifier to be connected to channel 5, this is covered in more detail
in the Brake dyno ‘quick start guide’ and in the chapter ‘Load Controller’ in this manual..
NOTE: In this diagram if the AFR meter was reversed it would damage the DYNertia3 unit. Make sure the meter is not
accidently connected incorrectly to the battery or to the DYNertia3 unit !
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Chapter 2: Hardware Installation
‘Linking’ Hardware to PC
Do not run other programs when using DYNertia3, background processes could interfere.
1. When you first run DYNertia3 you will be shown this Window. Press the “Continue OFFLINE” button, this is
necessary as DYNertia3 software does not yet know what PC communication port your control units are connected
to, it must be first ‘Linked’.
Once ‘Linked’ DYNertia3 will automatically find the hardware in future when it is connected, powered and the software is
started. If you plug DYNertia3 or Load Controller hardware into another USB port you may need to re-link.
This Window will also appear whenever DYNertia3 is started and the control units are not connected, powered or
‘Linked’. Pressing the “Continue OFFLINE” button allows you to continue to use DYNertia3 to view and analyse data ‘offline’ (i.e. with no hardware connected to the PC).
2. Power your DYNertia3 and Load Control units and plug the USB in, start DYNertia3 software, select the menu option
“Setup” and then choose “Communication” and then press the “LINK” button to DYNertia3 to automatically configure
the port interface. Then repeat for ‘Load Controller’ or ‘Weather Watch’ if connected.
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Chapter 3: ‘Brake’ Style Dyno Setup
Chapter 3: ‘Brake’ Style Dyno Setup
Setting up a brake (absorber) style dyno, instead or in addition to an
Inertia style Dyno!
The following basic information regarding brake type dyno’s
is relevant for an ‘open loop’ or ‘closed loop’ dyno system.
You must also refer to the chapter ‘Load Controller’ for
specific details on brake dyno setup, regardless of type.
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Chapter 3: ‘Brake’ Style Dyno Setup
Brake (Absorber) Style Dyno Setup
Basic concept
Brake (or absorber) style dyno’s rely on a device to apply load to the engine. In a chassis dyno, this device absorbing
the power (we will use the term 'brake' or 'retarder') is generally mounted on the end of the rollers shaft so its case could
rotate as a load is applied if unrestrained. It is this rotational force that is measured to calculate the torque. Engine dyno
have the brake either directly mounted to the engine or via a reduction drive (Eddy retarders have a limited max RPM)
The case is attached to a load cell sensor via a ‘torque arm’ that transfers the rotary motion into the linear one applied to
the sensor.
The length of the arm acts as a lever, so this can be designed to suit the measuring range of your load cell and give
appropriate sensitivity (or even made with several load cell attachment points for variability).
Note: We use the term "load cell" here for our 'torque sensor', but this can be an alternative style such as a hydraulic
master cylinder and pressure sensor or even a mechanical spring and coil type 'potentiometer'.
Note: Please see the chapter on ‘Load Controller’ for the load cell wiring and calibration procedures.
If we know the force (in Nm allowing for the length of 'torque arm') applied to the load cell and the RPM of the shaft we
can calculate power by the metric formula Kw = (Nm x RPM) / 9549, this will be power at the wheels. By using a chassis
dyno we can have a very convenient and quick way of testing modifications, unfortunately the effect of drivetrain losses
and tire losses do have an impact, an engine dyno avoids many of these ‘losses’.
See www.DTec.net.au website ‘downloads’ for information (‘Brake Chassis Design Tool’ or ‘Brake Engine Design Tool’)
The DYNertia3 controller senses the speed of the brakes rotating shaft and outputs this data, along with the load cell
information to the PC for analysis and storage.
DYNertia3 software package handles all the functions required of dyno acquisition: setting up, saving runs, correcting for
atmospheric conditions, filtering, displaying data, printing, overlaying and analyzing multiple runs.
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Chapter 3: ‘Brake’ Style Dyno Setup
Brake (Absorber) Style Dyno Setup (cont.)
Open Loop systems- You control he load manually, DYNerta3 does not have control over the brake.
Closed Loop systems- You can enter an RPM/speed and have DYNertia3 vary the load to maintain that RPM
automatically i.e. the load controller unit directly controls the brake and observes the result to allow continual adjustment.
Note: Basic DYNertia3 system alone does not control the actual brake/retarder load, this must be manually controlled. It
has ‘open loop’ functionality i.e. you cannot enter an RPM and have DYNertia3 vary the load to maintain that RPM
automatically.
For ‘closed loop’ control you need the optional ‘Load Controller’ hardware unit. For closed loop control of your load
please see web site for information on the ‘Load controller’ unit (also see the ‘Load Controller’ chapter in this manual).
In Brake mode, DYNertia3 uses Torque data from the load cell and roller RPM calculate Power. The measured Torque
is corrected to engine RPM (calculated from the dyno’s included sensor and ratio information or measured directly from
the engine). If the ratios are set incorrect then the readings will be incorrect i.e. if you just use roller RPM on a chassis
dyno then Torque will be shown as it appears at the roller only and not related to engine RPM. This is called ‘Tractive
Torque’ (Torque at the tyre) and will be higher than engine Torque due to the gears multiplying effects. It is really the
Torque delivered to the road and can be used as an effective tunning tool due to the increase in Torque resolution!
Variations
As noted earlier, some brake style dyno use a hydraulic cylinder (like a vehicle ‘master cylinder’) as the ‘load cell’, by
fitting a pressure sensor into the cylinder this provides the torque output. Alternatively some very old systems use a
spring assembly to counter the brakes rotation and then measure the displacement of this with a linear potentiometer
(position sensor).
Both can be interfaced into DYNertia3!
Mechanical instability will cause poor quality data, some old friction style brake dyno’s even have shock absorbers to
dampen movement (those just mentioned with springs in their load measurement system).
It can be very difficult to allow steady rising of the RPM for a ‘run’ without a good control system for your load, friction
brake systems are particularly difficult to operate smoothly and are often best operated for brief ‘steady state’ tunning
(‘Point by Point‘ mode is ideal). Excessive Inertia in your system can also cause difficulties on low power engines i.e. the
inertia load can end up limiting the acceleration during a test and not the load absorber device.
Types of testing used with brake (retarder/absorber) style dyno’s
Two main tests can be performed with a brake style dyno, a ‘ramp run’ or a ‘steady state’ test-
A ‘steady state’ test is where the load is applied until the engine RPM reaches a desired set point (with a fixed throttle
opening) and data is then recorded and displayed at that speed.
A ‘ramp’ test is performed by adjusting the brake load to allow the engine to accelerate through the RPM range whilst
DYNertia3 graphs the Power using the load cell as a Torque input.
Load cell calibration and wiring for Brake type
Please see the chapter on ‘Load Controller’ as the wiring and calibration procedures are explained there. Open loop or
closed loop control still uses the same load cell configuration.
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Chapter 4: ‘Setup’ Menu Options
Chapter 4: ‘Setup’ Menu Options
Hardware setup
Software setup
Communications setup
Sensor setup
Losses setup
Main Graph Appearance setup
Configuration reset
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Chapter 4: ‘Setup’ Menu Options
Hardware- Setup Menu
Brake / Inertia Button: Determines if you are using a brake
(retarder/absorber) type dyno or an Inertia type dyno. If you select a brake
style dyno then DYNertia3 will expect to see a ‘load cell’ input into channel
5 of the data acquisition connector. This will be used as the primary torque
input for Power calculations rather than the inertia value.
Chassis / Engine Button: Determines if you are using a chassis or
engine type dyno.
Tip- Helpful Tools!
Inertia Mass Constants: The dynos “Primary Mass” (the main dyno ‘flywheel’ and any significant rotating
components) inertial value is entered here (see “MOI” button for a tool to help calculate if not already known). If the dyno
design incorporates multiple selectable dyno flywheels then their values can be entered in “Second Mass” and “Third
Mass” to allow quick selection in main Dyno screen.
These extra masses are added to the primary inertia value when selected in the ‘Dyno’ screens “Record Settings” box.
The entry screen for roller circumference is only revealed when a chassis
dyno is selected.
The entry screen for tire circumference is only revealed when an engine
dyno is selected.
Roller Circumference: Used for chassis dyno’s to allow speed in kph/mph to be displayed if required (see “CIRC”
button for a tool to help calculate if not already known).
Tire Circumference: Optionally is used for engine dyno’s if you wish to display speed in kph/mph as oppose to just
RPM. The road speed can be simulated as the dyno will now know what distance would be travelled for every turn of the
drive shaft.
For an engine dyno, enter the distance in mm that the vehicle would travel per rotation of the shaft that the dyno speed
sensor is mounted to, not necessarily the actual ‘tire circumference’
Note: Units will be metric or imperial based on your choice in menu “Setup/Software”.
Mass RPM Limit: You can apply an RPM limit alarm to your system if you wish i.e. if there is a maximum safe limit you
wish for your mass/flywheel not to exceed. If DYNertia3 detects an over speed condition it will give very obvious alerts to
the danger and force an end to your test session.
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Chapter 4: ‘Setup’ Menu Options
Hardware- Setup Menu (cont.)
The entry screen for sensor/mass ratio is only revealed when an inertia dyno is
selected.
The entry screen for pulse generator is only revealed when a brake dyno is
selected AND the optional ‘Load Controller’ is configured (‘Linked’).
Sensor/Mass Ratio: On some special purpose dyno applications it may be that there is extremely low rotation speed
and therefore limited flywheel/roller timing data. This feature allows designs such as this to drive a sensor wheel via
gearing (or friction contact) at a higher RPM and thus can have the sensor trigger magnet speed applied rather than the
flywheel e.g. if the sensor magnet was spinning twice as fast as flywheel/roller then a value of 2 would be required.
It is also used where the sensor is not actually mounted on the flywheel/roller but on another shaft that rotates at a
different speed to the inertial mass.
Note: Trying to use this feature to allow triggering from multiple trigger targets on the flywheel/roller will result in poor
data quality; it will need excessive filtering to smooth out the ‘jitter’ from tolerances between your trigger targets.
Pulse Generator: The number of teeth on the trigger wheel is entered. See load controller chapter for details.
Tacho / Speedometer: The filtering speed determines the level of smoothing applied to the display. This has the effect
of displaying values that are not so wildly changing due to small cyclic variations in engine firing and dyno mechanical
tolerances.
Tip- Too large a ‘Smoothing’ numbers and disturbances that may be of interest can be hidden
OBDII Adapter input for Engine RPM and vehicle speed: If you have the optional OBDII interface (not available at
time of this manual) then you can choose to have this data used for various functions rather than just the calculated
RPM and speed (which is derived from the main flywheel/roller speed sensor).
RPM Adapter input for Engine RPM: If you have a suitable input adapter (such as DTec’s ‘RPM Adapter’) or sensor
connected to DYNertia3’s RPM Adapter input then you can choose to have this engine RPM value used for various
functions rather than just the calculated RPM (which is derived from the main flywheel/roller speed sensor).
NEVER connect ignition system directly to the RPM Adapter input!
RPM Adapter input is required if ‘slip’ analysis is to be performed. ‘Slip’ is dyno RPM compared to engine RPM, this is
handy for checking clutch engagement RPM or looking for loss of tyre traction on a chassis dyno.
It is important that if the RPM Adapter input is used then the number of pulses received that
represents a single engine rotation must be entered. It can be fractional e.g. 4 strokes only fire every
0.5 rev (which is once every 2 revolutions!) so “0.5” would be entered (2 stroke = “1”)
NOTE: Read the chapter “RPM Input Options” chapter for full setup details and “Inputs-
Using” chapter for connection!
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Chapter 4: ‘Setup’ Menu Options
Hardware- Setup Menu (cont.)
Brake Inertia Correction (Only in ‘BRAKE’ mode): If you have a brake style dyno and are performing ‘ramp’ runs
then the inertia of your dyno may be a considerable factor. If you select this option, and have the Inertia value correctly
entered, then DYNertia3 will basically operate as both Inertia and brake dyno simultaneously i.e. it will calculate the
power used to accelerate the mass as well as derive the power from the load cell.
Note: Excessive inertia built into a brake dyno (i.e. an inertia dyno with a brake added) will result in incorrect results as
high inertia will mean the load cell will not be reading as the brake will have no control of the ramp rate until power
overcomes the inertia effect, if at all!
After Run Auto Braking/Vehicle Loading:
Note: The use of the “Brake” output depends on the dyno type you
have setup. If you have a load controller connected then the settings
even alter to allow interaction with the operation of the eddy brake.
The ‘Brake’ output terminal may be used to operate an automatic brake for slowing the flywheel down if you wish,
operating a vehicle lift/jack to remove vehicle from rollers, an automatic cooling fan for friction style brakes or to control
the eddy retarder for vehicle removal if a load controller is fitted.
No load controller fitted- ‘Brake’ output terminal can go active from after a run is stopped and remain on for the time
set in ‘After Run Auto Brake’. It can also be manually activated for a pre-set time (‘Pulsed Brake Timeout’) or toggled
on/off at will.
load controller fitted- As above regarding the output terminal, however simultaneously in conjunction with the ‘Brake’
output terminal the actual eddy retarder is also powered with maximum power (to its set power limit). This function is for
locking the rollers to allow easier vehicle removal on a chassis dyno.
To allow this the ‘Retarder activated for vehicle loading/unloading’ should be enabled.
Besides the automatic function upon ending a test, the brake output
can alternatively be briefly operated (based on ‘Puled Brake Timeout’)
by manually selecting the icon (visible on both GRAPH and DYNO
screen) with a ‘Left’ click, this allows for setting up safely and also
applying brief braking pulses
Alternatively a ‘Right’ click on the icon will hold the output on
continuously until another ‘Right’ click is done again i.e. ‘Right’ click
toggles the output state. If not allocated to a brake; this output would be
perfect for remotely turning on a cooling fan etc.
Note: Further details for the complete output functions are outlined in the chapter “Outputs- Using”
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Chapter 4: ‘Setup’ Menu Options
Hardware- Setup Menu (cont.)
Hardware Connections: An overview of terminal designations on the
DYNertia3 hardware. Handy if your decals are not visible.
Circumference Calculator: Tool to help calculate your rollers
circumference if you do not already know it.
Units will be metric or imperial based on your choice in menu
“Setup/Software” (Imperial or Metric). Pressing the “Circ” button will
transfer the value into the “Roller Circumference” field in this ‘Hardware’ menu.
Moment Of Inertia Calculator: Tool to help you calculate the Moment of Inertia (MOI) of your dyno. If the
dyno design incorporates multiple selectable flywheels then their values can be saved separately as a
“Second Mass” and “Third Mass”.
Once the values of components have been entered into the rows they can be saved (or loaded) for later
use and reference.
Simply press one of the numbered buttons and the MOI value
will be directly transferred into the “Inertial Mass Constants”
field in this ‘Hardware’ menu.
‘Eraser’ button clears the filled in fields so new values can be entered.
From within the ‘MOI’ calculator you can press the icon of a weight to get a
reference of density of metals as shown here.
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