Partial fuelcut
With partially open throttle (ALS racecar) idleing and driving slowly is a pain.
Ignitioncut based idle pours a lot of exhaust through the engine, which has several problems
- fuel consumption
- fuel can burn in exhaust (and exhaust can cause fire)
- sparkplugs can be fouled
- fuel can wash down into engine oil, degrading oil
- possibly other
Fuelcut (individuel fueling events are skipped, with a pseudo-random algorithm, according to fueling demand) based power-control eliminates a lot of these. But care is needed, as always.
Configuration:
overrun_fuelcut - overrun_fuelresume = 10 that is 1000 RPM. If you don't want partial fuelcut, configure differently (like difference can be 900 or 1100 RPM)
example:
- overrun_fuelcut=23 (3500 RPM)
- overrun_fuelresume=19 (2500 RPM)
Which means
- when TPS <= iac_tps_threshold, fuelcut grows from 0..100% while RPM grows 2500..3500 (above that full fuelcut, injpw=0)
- TPS >= iac_tps_threshold + 25% no fuelcut at all (the +25% might change according to experience)
- when TPS between these, partial fuelcut is still allowed accoring to TPS and RPM:
- TPS pushes the 1000 RPM partial fuelcut window up by +4000 RPM / 24% TPS
TODO: RPM, TPS drawing, with angled "lane" going to higher RPM as TPS goes up
This means one needs to press the throttle to accelerate (than it will hold a certain RPM according to TPS). It's not exactly intuitive feeling, but at least drivable.
When making suggestions, make sure there are no sudden changes in the function. Any sudden changes result in engine stumble / twitch / jerks.