GenBoard/UnderDevelopment/FirmWare/PowerRelated (2005-05-14 19:06:51)

Power regulation related subpage of GenBoard/UnderDevelopment/FirmWare

A proposed power-target sublayer that consolidates

all are some way of controlling power, with a combination of


Unified fuelcut - minimalistic

overrun can be used to help race-start: Setting overrun fuelcut and fuelresume RPM to 3700 / 3400 RPM and applying a switchbutton that grounds the TPS signal. This way during race-start the rev is ideal for fast starting. (otherwise it is almost impossible to manually maintain the desired RPM with throttle and no load: the throttle is usually very touchy). The idle-air valve will close but who cares the throttle is opened anyway. Don't let the idle controller retard the ignition too much (a few degrees are OK).

After starting, switchbutton released, TPS signal back to normal, so rev-limit is raised to redline.

It would make sense to use a separate digital input channel (GenBoard/UnderDevelopment/DigitalInputs) instead of grounding the TPS signal: so 3 rev limits are possible.

Conditionfuelcut RPMfuelresume RPM
if TPS < tps_threshoverrun_fuelcutoverrun_fuelresume
else if the racestart switch is ONracestart_fuelcutracestart_fuelcut - (overrun_fuelcut - overrun_fuelresume))
in any case, if they are higher, they lowered torev_limit rev_limit - (overrun_fuelcut - overrun_fuelresume)
We have launch control implemented on a Peugeot NA racecar (that is actually at position 1 in the Hungarian rallycross series, though budget is only 1/4 of several competitors) using overrun fuelcut. TPS is fed from TPS5V (the main point is the 270 Ohm limiting resistor) and the "launch activation" button grounds TPS signal so the GenBoard applies overrun fuelcut (set at appr. 4000 RPM) though the TPS is mechanically pressed (butterfly opened). Plans are to change this a bit, because operating button on dash and handbrake simultaneously is hard (moving button to handbrake would work, but there is a better way, read on):