ECU Tuning April2010

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The following section section is a review of the basic setup procedure for for the ECU.

































The program can can be started from the ‘Start’ menu, or from a desktop shortcut. Both are added automatically during the installation. installation. If the ECU is connected, connected, the left side of the status bar will show the firmware version in green. Next to this are Diagnostic Errors in red. The screen above shows ECU Manager prior to opening the ECU file. The serial number of the ECU is displayed on the top left side of the screen. Below that is the list of options that have been enabled in this ECU. From either the ‘Adjust’ or ‘File’ menu choose ‘Open ECU’.

































When you connect to an ECU, the software checks to see if the current file in the ECU matches a file on the computer. If the file does not exist then a new file is created on the computer. If the file already exists then you have a choice of using the current file or creating a new file. It is good practice to create a new file if any major changes are to be made, this allows the original file to be at hand if anything goes wrong.

































The EMP software has a built in help system. When an item is highlighted, a help screen is displayed on the right hand side of the screen. You can also press the “ F1 “ key to get additional information where available. four. For two stroke or rotary engines a negative negative Number Of Cylinders: In this case four. number is used.

































Efficiency Efficiency selection sets the input sensor that is used for the “Y ” axis of the main Fu el screen. Typically set to Throttle Position for naturally aspirated engines and MAP for turbo engines.



































Load selection sets the input sensor that is used for the Y-axis of the main Ignition screen. Load and Efficiency do not necessarily have to be set the s ame.

































Injector scaling is the maximum injector opening time expected for the engine that is being tuned. This scaling value may need to be changed during the tuning process. Start with a recommended recommended scaling value.

































As explained earlier different injector types will need a different different control method. The Injector Current setting tells the ECU how to control the output to suit the injector. Injector current setting setting is based on the resistance measured across the pins of the injector. Care must be taken as some cars like Nissans and Mitsubishis can have extra resistors in series with the injector so it is also recommended recommended that the resistance be measured across the injector output and 12 V ECU supply s upply with the ECU unplugged. Press F1 for a list of popular injector settings.

































The ECU can add extra pulse width to account for changes in Battery Voltage. The table is 3D and would normally also be referenced referenced to Fuel Pressure. If no Fuel Pressure sensor is fitted a 2D table is all that is needed. Standard calibrations calibrations for popular injectors can be directly loaded from the “ Tools” menu. New or uncommon injectors may need to be tested by MoTeC. MoTeC.

































The Ignition outputs, like the injector outputs can control different types of ignition systems. Ignition Type Type specifies how the ignition outputs should be controlled. Some ignition modules need to be switched to power for the coil charging time (Dwell Time) and some are switched to ground. Care must be taken as an incorrect setting WILL damage the ignition system components.



































The coil dwell time is generally between 1.8 to 3 milliseconds. The dwell time is very small when compared to the time between spark firings, 20 milliseconds at 6000 RPM. At 6000 RPM if the wrong edge is chosen the coil will be dwelled for the 17 millesecond instead of 3 milliseconds, millisecond s, more than six times what is T

































The ECU will assign an ignition output for each individual coil.

































It is recommended that the Ignition Trim Percent or Degrees parameter be set as degrees.

































The Dwell table will need to be set for the particular coil/module in relation to battery voltage. It must be noted that too much dwell time can destroy modules the same way as choosing the incorrect ignition type so care must be taken. Too little dwell time and the spark will be weak.

































The ECU uses the mode number to understand the ref and sync signals that are being sent from the sensors. The ECU will base its ref/sync error checking on this number also.



















































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































Recheck all sensor readings with the engine running.

































































The Narrowband sensors were designed for one simple purpose, to be able to tell if an engine was running richer OR leaner than Lambda 1.00 (e.g. 14.7:1 for petrol) . A Narrowband sensor cannot be used for tuning where an exact mixture reading is needed. Narrowband functions in factory, and MoTeC ECUs, use narrowband sensors to quickly alter an engine’s fuelling from rich to lean so that the mixtures average at Lambda 1.00. Narrowband control control is usually only used for emissions and economy. economy.

































Wideband Lambda sensors are used during tuning when the exact mixture needs to be known. The Wideband Lambda sensors use more sophisticated devices to read them as the temperature change needs to be taken into account to be accurate.

































A few different different types of Wideband sensor can be wired directly to the ECU. The Wideband Lambda upgrade needs to be enabled to do this. Using the sensor input setup, set the Input Source and Calibration. The The Calibration is predefined for for the Bosch LSU 4.0, 4.2 and 4.9 sensors and the NTK UEGO.



































The actual Lambda sensor type needs to be specified as each sensor has its own specific way of being controlled. There is a “Fast Heat” and “Normal”. “Normal”. The fast heat setting brings the sensor online as soon as the ECU is powered, which is most suitable when doing cold start up tuning. The sensor in fast heat mode should s hould be online within 20 seconds of ECU power up. In Normal mode the sensor is off until there is engine RPM. Once the engine is started there is an extra delay time to let the exhaust system heat up. The delay time is dependent on engine temperature.

































The newer five wire Lambda sensors have a resistor in the connector that is used for calibration, calibration, the ECU does not use this resistor so its value must be manually entered. Sensors purchased from MoTeC will have the calibration number engraved on the sensor body. body. If the sensor is changed the calibration number must be changed to to suit.

































The five wire Lambda sensors have a Duty Cycle controlled heater. An Auxiliary Output must be set up a function “9”, “9”, the Duty Cycle of this output is used to maintain a steady sensor temperature. temperature. Note: Do not connect the sensor heater directly to an uncontrolled uncontrolled voltage source, this will damage the sensor.

































A MoTeC PLM is a stand alone Lambda meter. The PLM is able to transmit Lambda information information to other devices (ECU, SDL, ADL2) via an analogue voltage output or CAN communications. ECU upgrades are not required when connecting a PLM. All advanced Lambda functions are able to be used with PLM Lambda information, e.g. Wideband Lambda Control, Quick Lambda etc. The PLM has the facility to act as a “PLM Collect” unit which enables it to take Lambda information information from up to 11 other PLMs and transmit the information over CAN to another device.

































Firstly it is necessary to set up the ECU to receive the incoming PLM CAN message. In the CAN Setup we need to choose the first available CAN device and set “1” for PLM



































The Base Address tells the ECU which device on the CAN bus is sending the information.

































The ECU’s ECU’s Lambda input calibration calibration and input source need to be specified. Double click on the Lambda 1 input configuration.

































The Input Source is set as PLM 1 and the Calibration has a predefined setting for CAN Lambda. A default value and warning levels can be set.

































If using the PLM Collect function it is possible to assign twelve Lambda inputs to the ECU.



















































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































































On a dyno when tuning for maximum power it is possible that there can be large changes in ignition advance (and possibly fuel) between adjacent sites. These statically statically tuned values may produce the most power but can lead to light load drivability problems. It is often best to keep the changes of advance between sites to a minimum at light load. If a driver is “hovering” in an area of high change change the car can be difficult difficult to drive smoothly.

































When the throttle is opened rapidly there can be a large volume of air induced that may not be accurately catered for using the Main Fuel table alone. Acceleration Acceleration Enrichment is an extra amount of injector pulse width momentarily added to the current main table pulse width to compensate compensate for large, rapid changes in engine efficiency. Most Acceleration Enrichment is needed in the lower RPM range.

































The Acceleration Enrichment Clamp table sets the maximum amount of additional injector pulse width due to Acceleration Enrichment. The values values in this table are the same as the Main Fuel table, they are a percentage of the Injector Scaling. There is more need for Acceleration Acceleration Enrichment at lower RPM/Load. Note: At zero RPM there should generally be no Acceleration Acceleration Enrichment. Moving the throttle while starting the engine can cause flooding if there is any Clamp value.

































The Acceleration Enrichment Sensitivity table can be likened to the cam in a carburetor’s acceleratio acceleration n pump, the higher the cam ramp the more sensitive it is to rate of change of the throttle. The amount of extra fuel injected for Acceleration Acceleration is based on how quickly the throttle is moved. The sensitivity level is a multiplying factor factor of the throttle rate of change, the calculation calculation will give an injector pulse width which is added instantaneously instantaneously to the current injector pulse width.

































Once an extra amount of fuel pulse width has been calculated the ECU also needs to know how quickly that extra extra pulse width should be removed. The Acceleration Acceleration Enrichment Decay Decay table sets the percentage of the Acceleration Enrichment pulse width that should be removed with each revolution of the crank, e.g. if a pulse width has a decay rate of 10%/rev it will take ten crank revolutions before it is completely removed. Example: If 10 msec of fuel is added with a decay of 10% per rev, after one revolution of the crank the extra pulse width will be 9 msec, after the next revolution it will be 8 msec, etc. A higher decay decay number will remove the extra pulse width faster.



































When tuning the Acceleration Acceleration Enrichment the tuner will need to investigate what effect effect the throttle movement movement has on the Lambda reading. In the example above it can be seen that when the throttle is “floored” there is a short time where the mixtures go lean. It can be assumed that there is a need for roughly 8% extra fuel at this RPM. How much Decay is needed can be calculated from the time it takes for the Lambda reading to “recover”, e.g if the engine was doing 6000 RPM for 100 msec it would have done 10 revolutions, revolutions, divide 100% by 10 revs gives 10% per rev. Acceleration Acceleration Enrichment cannot be done accurately unless the main fuel map has been completely tuned.

































All MoTeC ECUs have the option to record data. The ECU has a menu system of various parameters parameters and channels which can be used to create a “Log Set”. Set”. Obviously it is impossible to have a laptop and tuner.

































The Data Logging Setup sets the logging rate for each parameter/channel parameter/channel that is to e rec recor e . zero va ue means e parame er s no o e ogg ogge e , a num er greater than zero zero means the parameter is to be logged and the number sets the number of times per second the parameter parameter will be logged. M400, M600 and M800 ECUs can log at rates up to 200 times a second (200 Hertz) Various parameters will need to be logged at different rates. RPM and Load (Throttle Position in the example) are logged at a high rate of 20 Hz because their values can change rapidly. Temperature channels like Air and Engine Temperature change fairly slowly and are generally only logged at 1 Hz, Exhaust Gas Temperatures for example will be logged at a higher rate. Pressing “N” will move to the next list of logging parameters, pressing “P” will move to the previous. There are 48 pages of up to 13 parameters so it is possible to record

































It is possible to set RPM points and delay times for logging. If the engine never goes above 2000 RPM while warming up the Start RPM parameter could be set to 2500 RPM, so no cold start fuelling is logged. A delay time of up to 20 seconds may also be desired. The logging in an ECU continually overwrites overwrites itself once it gets to the maximum logging time. This means that if the Logging Time is 30 minutes and the race is 50 minutes long the first 20 minutes will have been overwritten and only the last 30 minutes recorded. Knowing the limitations limitations of the logging overwrite and the final logging time it may be necessary to make sure the logging is stopped at the start of a cool down lap and the

































Open the MoTeC i2 software and choose the relevant Project.



































The i2 software will open at the last worksheet worksheet to be used previously. previously. Click on “File” and “Open Log File”, choose the log file to be analysed and double click.

































On a blank worksheet add a mixture map. The i2 worksheets work the same way as the screens in the ECU Manager software, software, right clicking in the blank area will produce an “Add” feature. Left click on Mixture Map.

































Choosing a Mixture Map will open a Mixture Map Properties dialogue box. The Channel should be set as Lambda 1 by default. Right clicking on the “Lambda 1” label will allow the scale to be changed if need be.

































On the “Load Channel” tab the Load channel needs to be set according to the Load sensor the engine tune was based on, e.g. Throttle Position, Position, Manifold Pressure etc. It is again possible to manually set set the scale maximum and minimum The band

































Using a Mixture Map display the Load and RPM range you wish to tune. Take Take note of the Lambda reading at each RPM and Load point that needs to be retuned. In the above example example take 100% throttle (in red) and 6000 RPM, the Lambda reading r eading is 0.91 La.



































































































































ECU Tuning April2010

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