SMT8-T5
Technical Manual V5
LetRipp II
Table of Contents: Page No:
INTRODUCTION.........................................................................................1
1.
2. HOW DOES IT WORK? ................................................................................1
3. CALIBRATION ...........................................................................................3
3.1
AMP CALIBRATION (Shift F4)................................................................3
3.2
ENGINE TEMPERATURE CALIBRATION (shift F5) .....................................4
3.3
RPM CALIBRATION ..............................................................................6
3.4
TPS CALIBRATION ..............................................................................7
3.5
DISPLAY OPTION ................................................................................8
4. TERMINOLOGY ..........................................................................................8
5. KNOW YOUR ENGINE .................................................................................9
6. SMT8T_5 PIN-OUT ...................................................................................10
7. COMMUNICATION WIRING and SEt-up .......................................................11
8. POWER WIRING ......................................................................................11
9. STARTING THE PC ...................................................................................11
10. PROFILES: PC SCREEN SETUPS..............................................................12
11. DYNO DISPLAY ....................................................................................13
11.1 INSTALLATION .................................................................................13
11.2 CALIBRATION ...................................................................................13
11.3 SETTING UP .....................................................................................13
11.4 PRACTICAL USE OF DYNO FEATURE ....................................................14
11.5 CALCULATING THE HORSEPOWER.......................................................14
11.6 PRACTICAL USE OF THE FUEL MONITOR ..............................................15
12. SMT8T_5 SIMULATION..........................................................................15
13. BASIC WIRING: FUEL MONITOR.............................................................18
14. BASIC WIRING: RPM ............................................................................19
15. BASIC WIRING: TPS .............................................................................21
16. IGNITION WIRING................................................................................21
17. DISPLAY WIRING .................................................................................22
18. SYSTEM SETUP ....................................................................................23
19. MINIMUM INSTALLATION AND WORK .....................................................23
20. ANALOG: AMP......................................................................................24
21. ANALOG: AFR ......................................................................................24
22. INJECTION ..........................................................................................25
23. BOOST CONTROL .................................................................................26
24. IGNITION CONTROL .............................................................................27
25. APPLICATIONS: LIMITING AN AMP SIGNAL..............................................28
26. APPLICATION: MODIFYING AN AMP SIGNAL ............................................28
27. APPLICATION: MODIFYING THE TPS SIGNAL ...........................................29
28. APPLICATION: PROVIDING FUEL AT BOOST VIA AN EXTRA INJECTOR ........ 29
29. APPLICATION: MODIFYING LAMBDA .......................................................30
30. APPLICATION: IGNITION MODIFICATION ................................................31
31. APPLICATION: BOOST CONTROL ............................................................32
32. AUXILARY OPERATIONS ........................................................................33
32.1 FREQUENCY MODIFICATION...............................................................35
32.2 PWM MODIFICATION .........................................................................35
32.3 BOOST CONTROL ..............................................................................35
32.4 DISPLAY OUTPUT ..............................................................................35
32.5 DYNO DISPLAY .................................................................................36
32.6 FUEL MONITOR.................................................................................36
32.7 PULLUP............................................................................................36
32.8 SUMMARY AUXILARY OPERATIONS .....................................................36
Table of Figures: Page no:
FIGURE 3. SMT8T5 pin out ..............................................................................10
FIGURE 4. SMT8T_5 DISPLAY ..........................................................................22
FIGURE 5. SMT8T_5 Switching.........................................................................34
1. INTRODUCTION
Congratulations on the purchase of the SMT8T_5. This piggyback unit is the result of
20 years experience in the automotive industry and is the latest design in the range
of SMT8 piggybacks.
The SMT8T_5 (SMT8T Version 5) is a further development from the very popular
SMT8T Version 3 and packs unsurpassed features in a very small size. The unit is
available through the dealer network as branded and public versions.
The SMT8T_5 is a tool for tuning and monitoring engine performance. This manual
will explain in a structured fashion each connection, the use and purpose of outputs,
and in general everything associated with the SMT8T_5. Once the unit is installed
you will need the LetRipp II Tuning software, and the LetRipp II Software User Guide
as well as a PC or laptop and a communication cable to get started.
If you are an experienced engine mechanic, then you will find some of the
terminology strange and can skip over familiar sections.
2. HOW DOES IT WORK?
The SMT8T_5 has two functions:
A) Monitor signals for display purposes
This function is a great tool during tuning, but is also great for collecting and
displaying data.
B) Modify signals for changing the engine performance
This is its traditional purpose!
The SMT8T_5 ‘modifies’ and measures engine signals. The signals are used by the
ECU to ‘drive’ your engine in a pre-determined fashion. By modifying the signals, we
can change the ECU’s response.
Example #1:
We all know that an engine runs richer when cold. So, if you want to run the engine
richer, you modify the temperature wire so that the ECU thinks that the engine is
cold. Then the ECU will enrich the fuel mixture.
Example #2:
Your engine has a Lambda loop. This means it controls the fuel mixture by a probe in
the exhaust. By modifying the probe output you can now ‘direct’ the ECU to change
the mixture to lean or rich.
Example #3:
The ignition point is derived from a crank sensor. By ‘delaying’ this signal you can
retard the ignition.
Note: The SMT8T_5 can also advance ignition, but we will not go into detail here.
In most cases the ‘modification’ involves the cutting of a wire (the signal wire) and
routing the engine side (source) to an SMT8T_5 input. Then the signal is modified
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inside the SMT8T_5 and presented as an output, which is then connected to ECU side
of the cut wire.
ECU
SMT8 T
Cut
CB1 + out
CB1 - out
CB1 + in
Pin 12 of 16
Pin 4 of 16
Pin 13 of 16
Cut
Engine
Magnetic Sensor
FIGURE 1. SMT8T_5 SIGNALS
The process by which the SMT8T5 ‘modifies’ the signal is called MAPPING. The
mapping involves looking up a number from a table, adding it to the looked up
number from another table, adding it to the input value, and output the result.
MAIN MAP
Signal input = A
-5
RPM
-
SIDE MAP (S)
+1+
Signal output
= A ± (-5+1)
= A - 4
The numbers, which are ‘picked’ from the tables, are selected by a TPS and RPM
scale, and in case of the ‘side table’ (the table on the side) from AMP or Engine
temperature scales.
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TPS
FIGURE 2. MAPPING
2
The above shows a typical ANALOG MODIFICATION map, which does NOTHING.
Of course the user can set the scales applied to the tables. The process is called
CALIBRATION.
3. CALIBRATION
It is a necessary evil requirement. For starters you can ignore it, but eventually you
will need to calibrate the SMT8T_5 for optimum results.
3.1 AMP CALIBRATION (SHIFT F4)
Calibration principle:
Let’s assume a linear sensor, such as the AMP. You need to know 4 values to
calibrate it.
A LOW voltage and the associated LOW pressure
A HIGH voltage and the associated HIGH pressure
A standard 1.15 bar AMP sensor has the following points:
LOW: 0.25V at 0.25bar
HIGH: 4.8V at 1.15bar
You can try and get the datasheet specification for the sensor, or you can do it as
follows:
Use the LOW setting: 0.25V at 0.25bar at position 1
Then use as the high setting the value obtained at ATMOSPHERIC pressure, which is
1.0 bar at sea level. Therefore:
HIGH: Input reading (V) at sea level=1.00bar
Of course the LOW/HIGH points don’t have to be at the end of the scales.
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3.2 ENGINE TEMPERATURE CALIBRATION (SHIFT F5)
The engine temperature is a little different, because the SMT8T_5 first LINEARIZES
the input voltage. Here is what you do:
Let the engine cool down over night, and measure its temperature. Let’s assume it is
18°C. Then use the displayed input reading (V) at point #6.
LOW: Input reading (3.5V) at 18°C, at point #6
Then warm up the engine until it has reached operating temperature. Let’s assume it
is 85°C.
HIGH: Input reading (1.25V) at 85°C, at point #18
You can shift the points up or down to cover the expected operating range.
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3.3 RPM CALIBRATION
The RPM calibration is different. You can only specify the LOW/HIGH end points.
Let’s assume we use 600 to 6000 RPM.
The UNLINEAR RPM scale looks crazy. BUT: Each RPM step is by the SAME
PERCENTAGE higher than the next one. Why? In this way the change in engine
parameters are constant.
Then there is the CUSTOMIZE option: You can type in the complete scale.
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The result of some customization may look like the following:
3.4 TPS CALIBRATION
Each car has a different TPS sensor. The calibration is needed to adapt the SMT8T_5
range to the mechanical range of your sensor.
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The UNLINEAR function is chosen. This is the preferred one, because the airflow
changes dramatically with very small butterfly openings. But, the other LINEAR and
CUSTOMIZE options are available.
3.5 DISPLAY OPTION
The SMT8T5 has an external display option installed. This option allows the use of
the AUXOUT pin 11 as a display output. For wiring check the BASIC DISPLAY wiring.
The AUXOUT output has 4 possible drives as indicated in the drawing below:
The AUXOUT pin can drive up to 8 displays, each display can display one engine
measurement from the DISPLAY list in the PC.
The choosing of an item (from the list) for display does not switch the AUXOUT pin to
the required configuration. This must be performed with the SYSTEM DEF. Finally the
Display can be switched off, which frees the AUX pin to a 2k2 pull-up resistor for
other purposes.
Applicable items from the SYSTEM DEFINITION:
Freq. Mod Tick for Frequency modification, otherwise PWM mod.
Boost Output Tick for Boost output, otherwise Freq. or PWM operation.
Enables DYNO or FUEL MONITOR
AUXIN to DYNO Enables AUXIN for DYNO operation, otherwise Fuel Monitor
Display on AUX Tick for display output, otherwise any of the above is output.
Display off Tick to switch display off
4. TERMINOLOGY
ECU: Your stock standard electronic control unit.
MODIFICATION: A means of changing a signal.
ANALOG: A voltage. The information is contained in the voltage level.
DIGITAL: A frequency. The information is contained in the transitions.
DISPLAY: An optional external display to the SMT8T_5
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MAPPING: The process, which results in the signal modification.
MAPS: A bunch of numbers. Only one number will be used for mapping at any given
time.
SIDE-MAPS: The same as maps, just smaller.
PARAMETERS: Single entry values, which influence a process as a whole.
SYSTEM DEFINITION: Click on/off points, which influence a process.
STATUS: A display, which shows the state of the SMT8T5.
DYNO: A convenient way to measure performance.
FUEL MONITOR: Monitors the ECU fuel injection in percent utilization
5. KNOW YOUR ENGINE
Obtain a wiring diagram from your ECU. This will show you the various engine
components. Apart from this you need to make some decisions as to the suitability of
your engine for the intended modification.
Does the engine use an AMP (Absolute manifold pressure) sensor, or a Mass Air Flow
sensor (MAF)?
In general an AMP sensor is preferred, because an MAF sensor has other
items attached: it may measure air temperature, it may have damping, or it
may have overshoot. There are some MAF sensors with a digital output, which
is un-suited for the SMT8T5. The AMP sensor is clean!
Does the engine use an ETC (Electronic Throttle control)?
The ETC is used during traction control. A little motor drives the butterfly. If
the engine uses an ETC, then the TPS input must be connected to the ETC
wires.
Does the engine use active ignition knock control?
This is difficult to determine. Use the ECU wiring diagram, or consult a brand
mechanic. If it has active knock control, then it is impossible to modify the
ignition point, because the ECU will ‘undo’ your modifications. Find out if your
engine uses knock control at wide-open throttle (WOT), or only during idle
and cruising. Whenever the active knock control is off, you can modify the
ignition point.
Does the engine use Lambda feedback?
Most engines do. There are TWO different exhaust probes: NARROW and
WIDE band probes. The SMT8T_5 has the ability to modify ONE Narrow BAND
PROBE.
If the answer to these questions is not obvious, then you need to consult a
knowledgeable mechanic or consult a friend. Of course, it all depends on the type of
modification you intend doing.
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6. SMT8T_5 PIN-OUT
13141516
78
FIGURE 3. SMT8T5 PIN OUT
PIN DESCRIPTION SIGNAL I/O
1 GROUND GND I
2 GROUND GBD I
3 BIPOLAR IGNITION OUTPUT BIPOUT O
4 NEG. CRANK OUTPUT -IGOUT O
5 AUX INPUT AUXIN I
6 AFR INPUT OXYIN I
7 ENGINE TEMPERATURE ENGTIN I
8 ANALOG INPUT ANIN I
9 INJECTOR/BOOST DRIVE INJECT O
10 PLUG BATTERY +13 I
11 AUX OUTPUT AUXOUT O
12 POS. CRANK OUTPUT +IGOUT O
13 POS. CRANK INPUT +IGIN I
14 ANALOG OUTPUT AOUT O
15 TPS (DEFLECTION) INPUT TPSIN I
16 AMP INPUT AMPIN I
5
6
4
101112
9
3
12
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7. COMMUNICATION WIRING AND SET-UP
The SMT8T_5 has a standard USB
interface. Once the PC is connected
to the USB port the unit will
function. Use the ‘SLOW 1.0’ USB
option on LETRIPP.
8. POWER WIRING
This wiring must be done for every application.
SMT8T_5
PIN 1 NEGATIVE, CHASSIS, of power source
PIN 13 POSITIVE, 6-12V, of power source
Once you apply power, the green LED will flash!
9. STARTING THE PC
Loading and configuring the PC is explained in the LETRIPP II Software User Guide.
This manual is located on your installation disk.
1. Start your LETRIPP II software. A screen must appear.
2. Click on TOOLS, Communication, and set: USB-1.0.
3. You should have communication within 3 seconds.
Once you have communication, you can ACCESS the SMT8T_5. The following is just
an exercise to familiarize your self with the LETRIPP II operation.
1. Click on COLUMN
2. F1 brings up the INJECTION map
3. Select a column, and type any number
4. Reset the unit via TOOLS
5. Click on UPLOAD, and observe that the entered number column is there
6. Load the DEFAULT values via TOOLS, Default
7. Click on UPLOAD and observe that all numbers are zero, except in the setup
screens.
Advanced task:
BLEND “G” numbers from one selected spot to the other extreme corner!
Blend numbers in a side table
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The following is a blend of the four corner values:
10 -10
-20 5
10. PROFILES: PC SCREEN SETUPS
The LetRipp II software can save your favorite screen ‘layout’. This is called a
PROFILE. That is to say which tables are open, and their position, and the display
points used. This is handy when you are coming back to an already performed task,
and are used to a certain layout.
The profiles are accessible through the Profile button. The Profiles do not change the
way the SMT8T_5 operates, but the way you monitor its behavior. You have to click
items on/off, and load a map from the hard drive to change the behavior of the
SMT8T_5. In Short: Profiles are a convenient way to put the things you want to see
on the screen.
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11. DYNO DISPLAY
The DYNO (Dynamometer) display itself can be seen on the PC screen or on the
EXTERNAL displays.
11.1 INSTALLATION
The DYNO feature utilizes the AUXIN input to measure road speed. The signal can
come from the:
Prop-shaft
Wheel
Speedometer
In the absence of any electrical road speed signal a magnetic transducer must be
installed and connected to the SMT8T_5 AUXIN, pin 5.
11.2 CALIBRATION
Open the DYNO SETUP screen (Config). The first field
Millimeter per AUXIN pulse
Must be set to an exact distance, if you work in the IMPERIAL system (See: Display
units) then you must still enter the distance in MILLIMETER. There are 25.4Millimeter
to an INCH! This completes the calibration!
11.3 SETTING UP
The SMT8T_5 Measures:
Time in seconds
Distance in Meters or Yards
Speed in Km/H or Miles/H
The unit of measure is chosen in the TOOLS, Display units!
A performance run (a DYNO measurement) is performed between two points:
A) The Trigger point, the starting condition
B) The end point
The following trigger points are available:
RPM trigger
TPS trigger
Speed Trigger
Enter a value in any of the above fields and the trigger point becomes active. Of
course, you can use more then one field, but then a LOGICAL ‘AND’ is performed.
The following END points are available:
Speed
Time
Distance
RPM
Set one END point ONLY! If more then one end point is set, then the first point is
serviced.
Finally, you need to assign the AUXIN pin to the dyno function by:
System Definition: Auxin to DYNO.
Click on it, and the ‘Dyno Ready’ status must show.
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11.4 PRACTICAL USE OF DYNO FEATURE
The SMT8T_5 displays three DYNO variables on the PC or external display. They are:
Dyno time in sec
Dyno Distance
Dyno Speed (Speed at end)
These items are updated at the end of a dyno run, and remain there until replaced
by the next run. If a run is aborted, then the values are not affected.
Depending on your preferences, you may display the applicable item or all.
Example #1: Measure time from 50 to 80 Miles
Set Tools: Display unit: Imperial
Enter 50 in Trigger Speed
Enter 80 in End Speed
Make sure other end and trigger points are zero!
Check that the status indicates: Dyno Ready
Find a level road without any speed restrictions
Hit the Gas!
At 50 miles the Status,’ DYNO Active’ comes on
At 80 miles the Status goes off, and the result is displayed!
Example #2: Measure time and distance for 100 meter standing start
Set Tools: Display unit: Metric
Chose RPM or TPS as a trigger, or a very low speed.
Enter 100 in to End Distance
Make sure other end and trigger points are zero
Check that the Status indicates: Dyno Ready
Find a level road without any restrictions
Hit the gas!
After 100 meters the results (Time and distance) is displayed.
Here are some practical hints:
If you repeat a run on the same road in opposite direction then you eliminate the
slope.
Do not underestimate the effect of wind or a slight breeze.
Check out the effect of fuel quality.
The Air temperature has an influence on the results.
Check out the effects of the side mirrors on high-speed runs.
Obvious reason to do a dyno run is performance tuning. The SMT8T_5 gives you a
very accurate tool to measure the effects of any changes you do to the engine.
11.5 CALCULATING THE HORSEPOWER
The unit has the ability to calculate the horsepower of the engine in Kilo Watt (KW) if
you perform a ¼ mile (=402 meters) run. You need to set the ‘End distance=402’
meters and perform a calibration as outlined above. This entitles:
Setting the ‘Millimeter per AUXIN’
Choosing a trigger point
Set the vehicle (including driver) weight in Kg
Setting the END DISTANCE=402
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Then perform a ¼ mile run from a standing start, and the unit will calculate two
different KW readings. Sorry, the real horsepower is not available, but here is the
conversion factor:
1 Kilo Watt (KW) = 1.36 HP Horse Power
KW calculated from the end speed (Trap speed method)
The speed at the end of the ¼ mile run is used to calculate the engine power.
KW calculated from the Time method
The Time it takes from start to the end (Dyno Time) is used to calculate the engine
power.
The formula is available from:
www.ajdesigner.com/phphorsepower/horsepower_equation_trap_speed
Both calculation methods yield surprisingly good results. If both differ too much,
then you can form a mental average, or ignore the higher reading. Practical tests
have shown that the numbers are fairly accurate, considering that the timing is only
performed with a 0.01 second resolution.
As outlined before, perform a run twice in the opposite direction to eliminate slope
and wind conditions. This is a great tool for tuning!
Of course you can shorten the distance. The KW readings are wrong because they
are based on ¼ mile, but you can get good comparative numbers out and see the
effect of your tuning efforts.
11.6 PRACTICAL USE OF THE FUEL MONITOR
The SMT8T_5 has a fuel monitor build in. All that is required is to connect the power
and the AUXIN, pin 5 to any injector.
NOTE: If one wire does not show any indication, take the other wire!
There are two display options available:
Fuel Utilization
Fuel Average
The Utilization is a ‘spot’ measuring and will show instantaneous reading. It displays
the duty cycle in percent. Typical readings are 0.5-1.5% at idle, and 50-85% at full
throttle.
The average reading has the same scale, but is averaged over 32 readings. This
gives a more stable display, but does not show any short-term fluctuations.
Both reading allows the driver to choose a speed (power), which is economical. With
experience this number can be matched to the actual fuel consumption.
12. SMT8T_5 SIMULATION
The purpose of the simulation is to experience the features and operation of the unit
on the desk before installation. Of course, if you have experience with piggybacks
then you can skip this section.
The following items can be simulated:
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RPM Simulation: Entry in RPM
It produces no ignition output signal, but the map deflection is affected.
TPS Simulation: Entry in Volt
It affects the map deflection, and if selected as an analog mapping input, the AOUT
signal is active.
AMP Simulation: Entry in Volt
It affects all AMP readings and maps. If it is selected for analog mapping then the
AOUT signal is active.
AFR Simulation: Entry in Volt
The AFR/Lambda readings are affected. If it is used for analog mapping then the
AOUT signal is active.
ANA Simulation: Entry in Volt
The Analog input and output readings are affected. If it is used for mapping then the
AOUT is active.
Engine Temperature Simulation: Entry in Degree
The display reading is affected.
Frequency Simulation: Entry in Hz
The display and the AUXOUT is affected
Simulation Exercise
Use the Simulation profile
Make the simulation field visible by clicking: CONFIG, SIMULATION.
Then Set RPM simulation: 2500
Then Set TPS simulation: 2.5V
Then Set AMP simulation: 2.5V
Then Set AFR simulation: 0.45V
Make the Status field visible: CONFIG, STATUS
Confirm that the Simulation is active.
Load any map: e.g. F3, Analog
After the above simulation settings your screen looks like:
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Simulation
Observe that the field indication somewhere in the middle of the tables is set. The
exact points depend on your scale calibration. The number in this field is used in the
mapping process.
Change the Set Simulation RPM to 3500RPM and observe that the point changes.
The following demonstrates an analog signal modification:
• Use the ANALOG SIMULATION profile
• Select in System definition: Analog Output.
• Display Analog input, Analog modification and Analog outputs
• Enter in Set Analog Simulation: 2.22V
• Observe that it shows as an input
• Enter a value in the Analog map at the field indication
• Observe that the modification display shows the field number
• Observe that the Analog output display shows the input PLUS the
modification.
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13. BASIC WIRING: FUEL MONITOR
Perform Power Wiring: Pin 10 = 12V
Pin 1 = Ground, chassis
Connect AUXIN to any fuel injector wire and check the display. If it doesn’t show a
result while the engine idles, then connect to the other injector wire.
In order to get a display:
System definition setup: Tick “Aux Boost”
Un-tick “Auxin Dyno”
Select display: Inject Utilization
Inject Average
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14. BASIC WIRING: RPM
The Rpm wiring can be done in two ways:
A) For RPM only
B) For RPM and ignition modification
This section assumes A) For RPM purpose only. For section B) See: Ignition wiring. It
is recommended to do this BASIC WIRING RPM first, and in any event.
Step1: Connect the +IGIN, pin 13 to any crank signal.
NOTE: Do not connect it to any injector or coil wire!
The crank sensor can be located on the crank, (on the CAM), or in the distributor.
Consult the wiring diagram of the ECU to locate the correct wire. If the crank sensor
has TWO live signal wires: use any ONE. Tee the +IGIN wire to the ECU signal wire.
Start the engine and observe that the STATUS, CRANK ACTIVE is indicated. Open the
Shift F1 PARAMETERS map and set: EDGES PER TURN to a number, which makes the
RPM indication correct.
Note: The amount of physical edges (Teeth) per crank turn must be entered.
For 60 teeth and two gaps, enter: 58
For 36 teeth and one gap, enter: 35
For 12 teeth, no gap: 12
You may want to change the SYSTEM DEFINITION: Neg. Crank Edge
High Crank level
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The above screen shows the effect of WRONG settings of EDGES PER TURN.
All the graph sections without the ‘spikes’ are good settings.
Note: Wrong setting produce an unstable and wrong RPM display!
This is a good point to calibrate the RPM scale. In the RPM calibration screen enter
the bottom and top RPM, and use the choice of linear/un-linear application. For detail
see: RPM CALIBRATION.
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15. BASIC WIRING: TPS
If your engine has an ETC (Electronic Throttle Control) then one of the wiper signals
must be used. Otherwise the TPS wiper signal must be used. In the absence of a TPS
signal, the AMP signal can be used. If neither of these options are available then you
have to be content with NO-MAP DEFLECTION. We strongly advise against it because
it reduces the two dimensional maps to a single dimension.
The TPS signal expresses the ENGINE LOAD or POWER.
Tee-in pin 15, TPSIN, to the available ECU signal
Use the TPS test profile.
Observe that the voltage is INCREASING when pressing the throttle.
If not, open SYSTEM DEFINITION, and click “INVERSE TPS”.
This is a good point to calibrate the TPS.
Use the TPS CALIBRATION profile or open the TPS calibration
At closed throttle: read the TPS INPUT % (of 5Volts)
Enter the calculated percentage as a LOW entry.
Open throttle completely and read TPS INPUT %
NOTE: Don’t do it with the engine running!
Enter the calculated percentage as a HIGH entry.
The above procedure works well with a TPS, but not well with an ETC signal. Here is
the solution: All ETC have two opposing ‘wiper’ signals. Calibrate the low entry on
the one you are going to use, and then temporarily connect the TPS input wire to the
other ETC wiper signal to calibrate the high (wide open) point.
16. IGNITION WIRING
This wiring is only recommended if ignition modification is required. It is not
recommended when:
A) The ECU performs knock control
B) The ECU crank trigger pattern is highly irregular
Warning: Your engine may stop with the wrong modifications.
Cut the Crank sensor(s) wire.
Connect the Engine side to pin13
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Connect the ECU side to pin12 (or pin 3 BIPOUT)
Start your engine and observe that it idles
If it does not idle, then:
The wiring is wrong
The System definition: Neg. Crank Edge must change
The System definition: High Crank Lvl must change
The Ignition error display shows the errors in 0.15 crank degrees per turn. If it is
<10 then it is ok. Otherwise change System definition: Neg. Crank edge. The System
setup: Teeth per turn may be wrong. If the car is not idling, despite all attempts,
then the ECU REJECTS the SMT8T_5. There are engines with high security ECU
inputs, which test the wires on startup and stop all operations if any irregularity is
detected. In these cases you cannot modify the ignition.
17. DISPLAY WIRING
If you are not using an EXTERNAL display, then skip this section!
The SMT8T_5 can drive up to 8 external optional displays. The AUX (pin 11) has a
multi function purpose, which must be selected with the SYSTEM DEFINITION. See
3.5 for details.
The displays are wired as follows:
Display
+12 volts
Display
off
Frequency
Frequency
Mod
Process
PWM
Process
Aux
Display
Boost
Boost Output
Process
FIGURE 4. SMT8T_5 DISPLAY
SMT8T_5 Display Wiring:
Display Signal SMT8T5
RED +13 Pin 10
BLACK GND Pin 1, 2
WHITE SIGNAL Pin 11
BLUE ADDRESS Do not connect
Pullup
2k2
Aux
pin 11
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The display wiring is not easy and requires a soldering iron. It is best that you enlist
the help of the local radio technician who can help you. The problem you encounter
is the result of the very thin wiring cord, which is nice to look at, but difficult to work
with.
The address wire (Blue) must be left open. It is used to assign an address to the
display if you have more than one display. A maximum of 8 displays can be used
with one SMT8T_5.
Address assignment
1) The unit displays the address 1-8 for the first 3 seconds after power up.
2) Put the address wire to +12 within 30 seconds after power up. The unit will
display the INCREMENTED address again for 3 seconds.
3) Proceed until the unit has the desired address and then tuck the wire away.
4) The assigned address is now PERMANENT.
18. SYSTEM SETUP
The System Setup is required if you like to detect correct RPM or want to do ignition.
Two parameter items are important:
Teeth per turn:
This is a little misleading. It should say: Theoretical teeth per crank turn.
For a 60 teeth wheel, with 2 missing teeth, you enter 60. This setting affects the
ignition (degrees) calculation.
Edges per turn:
This is the amount of ‘trigger’ edges per crank turn. The RPM is derived from it.
Teeth per Inject:
This is the amount of teeth between each injection pulse.
19. MINIMUM INSTALLATION AND WORK
I want to see results fast, and fix the details later. I hate reading (and writing)
manuals. Here is my approach:
Skip all calibrations
Wire power: Pin #1 to ground
Pin #10 to +12 battery
The green LED should flash
Choose your weapon: Analog modification: AMP, or AFR
Injection
Boost control
(Ignition control)
If you are new to this: don’t attempt ignition control as your first job!
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20. ANALOG: AMP
Locate the AMP signal wire and cut it
Wire the sensor side (from the engine) to pin 16
Wire pin 14 to the ECU side (to the ECU)
Set in SYSTEM DEFINITION: AMPIN to AOUT
Start the engine
Your engine should run as normal.
The GREEN cursor indicates where the engine runs.
Enter a number in this spot: let’s say 20, and observe that the engine tune changes
It works!
Now you can do calibration, mapping, limiting.
21. ANALOG: AFR
Locate the signal wire and cut it
Wire the sensor side (from the engine) to pin6
Wire the ECU sire (to the ECU) to pin 14
Set in SYSTEM DEFINITION: OXYIN to AOUT
Start the engine
Your engine should run as normal.
The GREEN cursor indicates where the engine runs
Enter a number in this spot: let’s say 20, and observe that the engine tune changes
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It works!
Now you can do calibration, mapping, limiting.
Note that the ECU will ‘undo’ your modification after a while.
22. INJECTION
This is a little tricky; you need RPM to trigger an injector output.
Connect pin 13 to the crank signal. Anything you can find.
While the engine runs check that the STATUS, CRANK ACTIVE comes up.
You should see the following:
Note that the Inject Active is only bold when the extra injector is operating
The unit drives an injector from pin 9
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23. BOOST CONTROL
You need an AMP input from a sensor that is able to read boost, which is compared
to the target (but can do without it).
The boost output must be directed to an output. This is done in the ‘System
Definition’:
Boost on INJECT The boost signal is on pin 9, INJECT
Boost on AUX The boost signal is on pin 11, AUXOUT
The unit outputs a PWM signal to the specified pin (or both).
The PWM (On time, low) is calculated as follows:
Boost Out=Boost PWM+Boost Eng.Temp + (Amp input-Boost Target)*Boost Gain
Important: System definition: Boost on INJECT or Boost on AUX
Status: Boost Active
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24. IGNITION CONTROL
Perform the Ignition wiring:
Enter a NEGATIVE=RETARD number at the green cursor and observe that the engine
tune is changing.
Note: Despite wrong setting as follows, the unit defaults to RETARD ONLY and the
engine runs retarded.
Summary: it is possible that the ECU rejects the SMT8T5 all together and it is
possible that you can do RETARD only if the crank pattern is irregular, or very
coarsely spaced. Teeth per turn below 8 may have a problem in advancing.
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25. APPLICATIONS: LIMITING AN AMP SIGNAL
You have added a supercharger or turbo to the engine and the engine light comes on
as soon as you are boosting. The fuelling is done somewhere else.
Perform power wiring
Find and cut the AMP signal wire
Connect engine side to pin16
Connect ECU side to pin14
Tick System definition: AMP Output
Enter the LIMIT VALUE in Parameter: Ana Upper Lim V and Ana Lower Lim V
That’s it!
26. APPLICATION: MODIFYING AN AMP SIGNAL
You have changed the fuel pressure or the injectors to provide more fuel. As a result
your engine idles badly. You need to change the AMP signal down so that the ECU
injects less fuel.
Note: This may not be possible at idle, because you may exceed the lower
ECU voltage limit!
Perform power wiring
Locate and cut the AMP wire
Wire the engine side to pin16
Wire the ECU side to pin14
If the ECU complains about the low AMP voltage, then you can set the Parameter,
Ana Low Limit setting to prevent this.
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27. APPLICATION: MODIFYING THE TPS SIGNAL
You like to restrict the cars performance to a safe level. This can be helpful during
servicing.
Note: This mod does not work with ETC!
Perform power wiring
Locate and cut the TPS wire
Wire the engine side to pin15
Wire the ECU side to pion14
Perform the BASIC RPM wiring
Click System definition, TPS Output
With this mod there will be a big power loss after 3000RPM and after 65% TPS
position.
28. APPLICATION: PROVIDING FUEL AT BOOST VIA AN EXTRA INJECTOR
You have added a turbo, and need more fuel at boost. The extra injector is installed
before the butterfly. This is the only way to get more fuel in to the engine when the
injectors saturate, or when increasing the injector flow rate is not an option, or when
the increase in fuel pressure is not an option.
Perform Power wiring
Perform Basic RPM wiring
Connect EXTRA injector(s) to pin9
Connect an Addition AMP signal to pin16 ( most standard AMP sensors can only read
as high as atmospheric pressure)
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Note:
The System definition: Inject Fuel Extrap is set
The AMP gradient from 1.00 bar to 2.00 bar is arbitrary
The AMP side table multiplier set to zero will result in zero injection
The main map has a slight increase towards WOT
It can decrease towards 6000 RPM
29. APPLICATION: MODIFYING LAMBDA
You either want to save fuel or gain extra power.
Note: Lambda signal modifications make sense only when:
A) The engine uses a NARROW BAND sensor
B) The ECU has FULL or partial closed loop Lambda
Perform Power wiring
Perform Basic RPM wiring
Locate and cut the Lambda wire
Connect the engine side to pin6
Connect the ECU side to pin14
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Note: During cruising if the map entry is 10, the SMT8T5 adds 0.1 volt. This makes
the ECU input RICHER and subsequent the ECU will reduce the fuel, which results in
a LEANER operation. At full power the SMT8T5 subtracts 0.1V, which makes the
signal LEANER. The ECU will then add fuel, which results in a RICHER operation, and
more power.
30. APPLICATION: IGNITION MODIFICATION
You have added a turbo or supercharger and need to eliminate knocking. Or you are
using Ethanol and want to advance the ignition. Or you are using high-octane fuel for
racing.
Perform Power wiring
Perform Ignition wiring
Perform SYSTEM SETUP
Check that you display correct RPM and that the Ignition errors are <10.
Set the Parameters: Ign Adv Lim and Ign Ret Lim to suit your needs
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Negative
entry for
during Boost
Positive
entry
Note: POSITIVE entries ADVANCE
NEGATIVE entries RETARD
Entries are in crank degrees.
31. APPLICATION: BOOST CONTROL
You have added a turbo to an engine without de-compressing it and need to control
the boost. This requires a ‘turbo canister’ of the lowest SAFE boost pressure,
normally 0.2-0.35 bar. The SMT8T_5 can regulate up, but not down.
Perform Power wiring
Perform Basic RPM wiring
Wire the Boost solenoid to pin9
Wire the AMP signal to pin16
Click System definition: Boost on AUXOUT
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The boost PWM output signal opens the ‘BLEED VALVE’ which reduces the canister
input pressure, and closes the bypass valve, thus INCREASING the boost:
MORE PWM = MORE BOOST
If the target pressure matches the boost pressure, then the BOOST PWM plus the
BOOST ENGT PWM are output. This is the base line PWM. It is modified with the
TARGET DIFFERENCE times the BOOST GAIN (Parameter (0 disables the Boost
Target)).
The BOOST GAIN is not critical. If it is too high the pressure will oscillate, if it is too
low then the pressure will ‘creep’ up.
32. AUXILARY OPERATIONS
The SMT8T_5 has an AUXILARY input, AUXIN, pin 5 and a auxiliary output, AUXOUT,
pin 11.
This channel can be used for a multitude of applications:
Frequency modifications:
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An input frequency is modified via the Freq/PWM map and output.
PWM (Pulse Width Modulation) modifications:
A PWM signal is modified via the Freq/PWM map and output.
Boost control:
A Boost control PWM signal is output
Display output:
The display signal is output on the AUXOUT, pin 11.
DYNO monitor:
The AUXIN signal on pin 5 is used for DYNO performance displays.
FUEL MONITOR:
The AUXIN, pin 5 signal is connected to a ECU injector for fuel consumption
measuring.
PULLUP Resistor:
The 2k2 pull up resistor can be used for other purposes when needed.
The following diagram shows the rather complicated switching arrangement:
Display
off
Display
Aux Out
pin 11
Frequency
Process
PWM
Process
AuxFreq
Mod
Aux
Display
Pullup
2k2
+12 volts
Aux in
Pin 5
Aux Boost
Boost
Process
Aux Dyno
Dyno
Fuel
Monitor
Fuel
Injection
Aux Boost
Boost Inj
Inject
Pin 9
FIGURE 5. SMT8T_5 SWITCHING
Note: Various functions can be run simultaneously!
Here is what needs to be done to activate the various functions:
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32.1 FREQUENCY MODIFICATION
Input: AUXIN, pin 5
Output: AUXOUT, pin 11
Setup: Aux. Freq. Mod tick
Boost on AUXOUT off
Display on AUX off
Display off off
Other functions:
Boost can be directed to the INJECT, pin 9
DYNO not available
FUEL MONITOR not available
32.2 PWM MODIFICATION
Input: AUXIN, pin 5
Output: AUXOUT, pin 11
Setup: Aux. Freq. Mod off
Boost on AUXOUT off
Display on AUX off
Display off off
Other functions:
Boost can be directed to the INJECT, pin 9
DYNO not available
FUEL MONITOR not available
32.3 BOOST CONTROL
Input: AUXIN, pin 5
Output: AUXOUT, pin 11
Setup: Aux. Freq. Mod off
Boost on AUXOUT tick
Display on AUX off
Display off off
Other functions:
Boost can be directed to the INJECT, pin 9
DYNO: Auxin to dyno tick
FUEL MONITOR: Auxin to Dyno off
32.4 DISPLAY OUTPUT
Input: not required
Output: AUXOUT, pin 11
Setup: Aux. Freq. Mod off
Boost on AUXOUT tick (input can be used by DYNO/FUEL)
Display on AUX tick
Display off off
Other functions:
Boost can be directed to the INJECT, pin 9
DYNO: Auxin to Dyno tick
FUEL MONITOR Auxin to Dyno off
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32.5 DYNO DISPLAY
Input: AUXIN, pin 5
Output: AUXOUT, not required, can be used by BOOST or DISPLAY
Setup: Aux. Freq. Mod off
Boost on AUXOUT tick
Display on AUX off (as required)
Display off off
Other functions:
Boost can be directed to the INJECT, pin 9 or AUXOUT, pin 11
DYNO: Auxin to Dyno tick
FUEL MONITOR Auxin to Dyno off
32.6 FUEL MONITOR
Input: AUXIN, pin 5
Output: AUXOUT, not required, can be used by BOOST or DISPLAY
Setup: Aux. Freq. Mod off
Boost on AUXOUT off
Display on AUX off
Display off off
Other functions:
Boost can be directed to the INJECT, pin 9 or AUXOUT, pin11
DYNO: Auxin to Dyno tick
FUEL MONITOR Auxin to Dyno off
32.7 PULLUP
Input: AUXIN, not required, can be used
Output: AUXOUT, 2K2 pullup
Setup: Aux. Freq. Mod off
Boost on AUXOUT tick
Display on AUX tick
Display off tick
Other functions:
Boost can be directed to the INJECT, pin 9
DYNO: Auxin to Dyno tick
FUEL MONITOR Auxin to Dyno off
32.8 SUMMARY AUXILARY OPERATIONS
It is a little complicated, but allows a multitude of functions to use the same input
and output pins. The above ‘switching diagram’ explains it the best. Further versions
of the SMT8T will see some changes in the auxiliary signal assignment.
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