Rev Limit Parameters
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Note: All rev limiters operate via fuel cut.
Overall Rev Limiter
This is the main engine speed limiter value.
Do not increase the rev limiter unless you are sure all the components of the engine will withstand the greater stress.
Launch Control and Full Throttle Shift
Launch control works by limiting the engine speed to a pre-determined rpm in order to give more consistent launches. Full throttle shift limits the engine speed while shifting so that the throttle does not need to be released.
Both launch control and full throttle shift use a shared clutch input, with Launch Control being active when the vehicle is stationary and Full Throttle Shift activating when the vehicle is moving.
It is possible to retard timing and add fuel in order to spool a turbo when launching, and to keep the turbo spooled when shifting.
Note that both Launch Control and Full Throttle Shift uses stock rev limiter behaviour, and thus may not be suitable for certain engine combinations and launch rpms.
The clutch switch is used to trigger both launch control and full throttle shift. It is important to use a clutch switch which triggers close to the clutch engagement point. For this reason, the starter disable switch and cruise control switch are not suitable for use as a clutch switch. The best solution is to add a micro switch which triggers close to the clutch engagement point.
Fuel & Ignition retard activation RPM - determines when the fuel and ignition should be adjusted while using the launch limiter. Normally this should be below the launch rpm limiter, otherwise the fuel and ignition changes will not take affect.
Launch RPM limiter - sets the launch rpm limit.
Maximum Speed - is the vehicle speed where the launch control is switched off and full throttle shift operates. Normally this is 3-5 mph.
Fuel Enrichment - is the amount of fuel to add or remove. Note that this setting is shared with Full Throttle Shift.
Ignition Retard - is the change in ignition timing. Note that this setting is shared with Full Throttle Shift.
To spool a turbo and built boost it is recommended to retard the ignition as much as possible. Note that the actual ignition advance is limited to 10 degrees after top dead center.
Retarding the ignition and adding fuel in order to spool a turbo will result in a rapid increase in cylinder head, manifold, turbo and exhaust temperature.
Full Throttle Shift
Fuel & Ignition retard activation RPM - determines when the fuel and ignition should be adjusted during a shift. Normally this should be below the shift rpm limiter, otherwise the fuel and ignition changes will not take affect.
Launch RPM limiter - sets the shift rpm limit. Normally this is the average rpm for the next gear after a shift - approximately 20% less than the shift point, around 6000-7000 rpm.
Burnout Rev Limiter
The burnout rev limiter acts as the normal rev limiter would. Unlike the launch limiter, the burnout limiter does not depend on the speed of the vehicle. The burnout limiter uses a separate clutch switch from the launch control/full throttle switch so that both controls can be enabled or disabled without having to reflash the ECU. Note that the burnout limiter will override all limiters until it is switched off.