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This groups of maps were adjusted individually depending on the which map was being used when tuning. The distance along the track determined by the HDFX maps picks which of the mapped pairs that are used to determine the ignition timing. It is also worth having the table for "Ignition Timing Source" use the logging parameter to confirms where the current timing value is coming from.
Parameter Display | Description |
|---|---|
Crank/Unspeed | Ignition timing from the cranking tables |
Base | Base map values being used |
Borderline | The borderline spark tables are being used |
Torque Control | Torque control strategies like idle, take off assistance and torque arbitration. |
Pre-ignition | Low speed or high speed pre ignition mitigation maps (LSPI and HSPI) |
Cylinder Pressure | Any of the cylinder pressure limit maps |
Stable Low Load | The combustion stability limit ignition timing maps (see limiters) |
Cold Low Load | Cold start emissions reduction (CSER) based ignition adjustments |
Idle FBS at Min Clip | Idle feedback based spark limits |
Idle FBS | Idle Feedback based spark control |
KOER | Engine running test mode for emissions reduction timing |
OSC | Output state control override of final spark advance |
Foregrnd B/L Clip | Rapidly updated borderline value further limited by throttle tip-in events |
C/T Decel | Fuel cut and decel timing |
The adjustments to this map have been made only in the high load and RPM regions and there are only minor changes in the mapped pairs that are used when in economy etc. Most of the time on the dyno it will be in optimum power mode and this map has been increased by up to 6 degrees in some regions.
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Airflow limit source logging parameter values
Paramater Display | Description |
|---|---|
NOCLIP | No Airflow limit |
INJDC | Injector duty or open time based airflow limit |
WGC | Waste Gate Control based airflow limit |
EXT | Exhaust Temperature based airflow limit |
MAF | Measured airflow limit |
POPCORN/LSPI | Low Speed ignition limit |
PART PEDAL | HDFX based airflow limits |
FSC | Fuel system pressure based airflow limit |
When the value is 6 "PART PEDAL" the load limit maps are the mapped pairs below found in the HDFX Load tree, these maps have been raised and profiled to allow the boost to torque to rest on this load limit map
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The OEM method for boost control is quite complex and to help in breaking down limits and targets many new logging parameters have been added. The logging parameters below will help you to spot any issues that come from using the example ROM.
Parameter Name | Description |
|---|---|
Boost Actual | Boost sensor output in kPa, should be in same units as the rest really! |
Boost Control PID Base | WG duty base component before PID correction (this may be for another unused strategy) |
Boost Control PID Derivative | D component of PID correction, usually only significant in spool |
Boost Control PID Derivative Error | Lookup used for the derivative map |
Boost Control PID Integral | This is very useful as it can highlight if integral is hitting limits which can be raised. |
Boost Control PID Integral Error | Lookup used for the integral map |
Boost Control PID Prop | Proportional error correction, difficult to link to a single map will update with more info on that later. |
Boost Error | Error in inHg which can be useful with current kPa/inHg mismatch |
Boost Target | Self explanatory, the desired TIP or Throttle Input Pressure |
Dig:Airflow Limit Source | This can sometimes be triggered by boost control strategy, which can be seen in your logs, typically turbo outlet temp, (estimated) turbo speed limits, mass flow limits etc. |
Manifold Absolute Pressure | Pressure in manifold, typicallly lower than boost |
Manifold Air Temperature | The RS has a combined MAP/MAT sensor that gives manifold temp |
MAP Desired | The desired manifold pressure as converted from load/torque used to give desired TIp (Boost Target). |
Mass Air Flow | Give in lb/min and use for a number of maps used in boost control |
Turbine Flow Fraction Desired | The relative proportion of exhaust flow requested to go through the turbine instead of via the waste-gate, can go higher than 1.0 meaning the ECU demands all the gas to go through the turbine, so will tend to fully shut WG, and it wants still more gas through the turbine to generate enough shaft power to drive the compressor to make the required airflow/boost |
Turbine Flow Fraction Estimated | Proportion of flow estimated to be going through the turbine, shouldn't go above 1.0 and most of the time outisde spoolup the estimated/desired values are almost identical. |
Turbocharger Bypass Valve | Output to the solenoid that controls the dump valve, which is drive by vacuum supplied by cam driven vacuum pump (also used for brake servo vac) |
Turbocharger Wastegate Duty | Exactly as described. |
WG Canister Pressure | The estimated pressure in the wg actuator used to open it, the higher this is, the more the WG will open and the lower the boost will be. |
WG Canister Pressure Des | The desired pressure in the wg actuator. Desired and estimated values appear to be the same almost all the time. |
WG Duty From Turbo Power | This is the WG duty as determined by the turbo (shaft) power control strategy, unsure if this is pre or post PID corrections. |
Anti Jerk control
The Factory Anti Jerk control can sometimes hamper initial performance, some fine tuning of the anti jerk control was adjusted as required to improve this.
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