SM4 Manual
by
MRM-Racing
V3.0
99
Used to control how aggressively the boost valve is controlled to try and achieve the set
point value. Lower value will give slower response but more stable boost with less
spiking.
•
Do not worry if the boost is above or below the set point. Use this setting to get a
smooth boost line with minimum spiking, then use the boost offset tables to correct
the pressure and get a flat boost line.
Boost offset
Used to correct actual decreases or increases in boost that occur above or below the
desired boost levels set in boost set point tables. Setup this table after the boost
controller is tuned and stable using the control range and dynamic comp settings.
Correction values of –128 Kpa to 127 Kpa can be used.
Y axis for table can be setup under "Table axis setup".
Default Y axis=Boost setpoint
•
Tune this parameter last.
Boost modifier
Boost modification.
Used to reduce boost pressure in relation to other variables.
Example:-
Boost can be reduced on high inlet air temperatures or made throttle position
dependent.
X and Y axis can be setup under M5 Table axis setup
ECU limits setup
ECU limits setup
•
Rev limiter
Hard cut(H)=all injector or all ignition outputs are cut.
Softcut(S)=one injector or one ignition output are cut at a time. Increasing the
number of injectors or ignition outputs that are cut until the engine RPM is
controlled.
You can select between combinations of soft and hard. Turbocharged engines
should use injector soft or hard cut or ignition hard cut. Soft ignition cut can cause
backfiring in the exhaust which can damage a
turbocharger.
Tip:
When using a internal wastegate the size of the restrictor has a big effect on
all the settings. Adjust restrictor size, control range and dynamic comp to
achieve a smooth (10kpa or less movement) boost line. If you find you cannot
stop the spiking or over boost, try a bigger hole in the restrictor. Also if the boost
is too low a smaller hole should be used.
When adjusting these settings do not worry if the boost is too high or low or not
flat. The boost offset table are used to correct this.
