Rev limiters
Rev limiters can be found under Base Engine > Limits and fallbacks.
Hard cuts
Hard cuts apply when an engine reaches the RPM hard limit. In most cases, it is recommended to use fuel cut instead of spark cut.
Fuel cut
If Cut fuel on RPM limit is set to yes, FOME will stop injecting fuel once the engine reaches the RPM hard limit. The engine speed must drop below the RPM hard limit by the number of RPM specified in Hard limit hysteresis before fuel injection is resumed.
Spark cut
If Cut spark on RPM limit is set to yes, FOME will stop firing the ignition coil(s) once the engine reaches the RPM hard limit. The engine speed must drop below the RPM hard limit by the number of RPM specified in Hard limit hysteresis before ignition is resumed.
If Cut fuel on RPM limit is set to no then fuel will continue to be injected during the spark cut. This can cause a build-up of unburned fuel in the exhaust system which may ignite when ignition resumes and can cause damage to the engine and exhaust system.
Cutting spark can lead to engine valvetrain damage due to the immediate reduction in torque. It is recommended to use fuel cut instead of spark cut in most cases.
Both cut
Both fuel cut and spark cut can be used together. This reduces the risk of unburned fuel in the exhaust when using spark cut, but the risk of valvetrain damage still applies.
Soft limiting
Electronic Throttle Limiting
Engines equipped with an Electronic Throttle Body (ETB) can utilize Electronic Throttle Limiting. This will smoothly close the throttle starting at the Soft limiter start engine speed and fully close it once the engine speed has increased by the number of RPM defined in Soft limiter range.
For example, if Soft limiter start is 6000 RPM and Soft limiter range is 200 RPM, the maximum ETB position possible at 6100 RPM is 50%, and at 6200 RPM the electronic throttle will be fully closed even if the accelerator pedal is commanding a larger opening.