EGbeater

iTrader: (35)

I've searched both here on evom and on Google, and can't find a definitive answer. I'm asking about the OEM ECU's rev limit that engages when the car's moving, not the stationary one for the two-step function.

This thread says it DOES cut fuel:

https://www.evolutionm.net/forums/ev...v-limiter.html

The last poster in this thread says it cuts ignition:

http://30-130.com/showthread.php?p=1126354

And the availability of the Bee*R auxilary rev limiter implies that fuel cut rev limits aren't rare... plus, in the evom thread below, a representative of Gruppe-S claims the Evo DOES use a fuel-cut rev limiter:

https://www.evolutionm.net/forums/gr...v-limiter.html

This is not a launch control or 2 step! Its a rev limiter that will cut out the ignition when you hit your "set" rev limit. The stock ECU will cut fuel when you rev to 7600rpm but the ignition will still be on. With the Bee Rev limiter, the ignition will be shut off therefore causing a fireball when bouncing off the rev limit. However, "flame" isn't the idea...this unit is to protect your engine from a spun rod bearing.

Thanks,
Tom

In case it matters, I have a 2006 Evo 9, not an Evo 8.

RaNGVR-4

iTrader: (4)

Lets look at this empirically:

-A fuel cut, if anyone has experienced it, is like hitting a brick wall. It is exceptionally violent. Not good for a rev-limit

-A fuel cut would lead to a very lean condition. At high rev's, this would almost certainly blow an engine up.

-When the rev-limit is reached, black puffs of smoke can be seen from the exhaust-> Points to unburnt fuel or a rich mixture

-A 2-step limit (Launch Control) is just a dual limit. One is active when the clutch is depressed, the other when it is not depressed. The actual limiting itself operates int he same way. If it was a fuel cut, there would be no unburned fuel to be ignited through the exhaust turbine, therefore no boost would be made while free-revving. Logically, the normal rev limit would be exactly the same, it would just retard timing and/or cut spark just as the LC limit does.


So, purely logical thought points to a timing retard/cut rather than a fuel cut. It would be very unsafe for both engine/driver to have a fuel cut as a rev-limit.

Is that the actual case though? I don't know, but I'd like to.

EGbeater

iTrader: (35)

Nobody knows? Or cares?

tephra

iTrader: (6)

fuel cut

log your IPW's and watch them drop to 0 when you hit revlimit

EGbeater

iTrader: (35)

Thank you tephra. Sorry, I've never logged my Evo during an autocross run, or I wouldn't have needed to ask this question.

tomgsr

I think it uses the ignition cut as black smoke comes out of exhaust and it back fires. Feels as if it's just dumping fuel into the engine that isn't burning.
Just listen to my YouTube link. Does not sound like it's cutting the fuel
https://youtube.com/shorts/ZIYcxlMaI...LKUvpmQfm7CQen

RobbieOh

Hella necro..