OFT spark cut for LC to shoot flames and at rev limiter to not lose power drifting

[Hybrid707]

Hello, as the title says I was wondering if there was any way to change the rev limiters to spark cuts instead of fuel cuts so I can A. Possibly shoot a flame with launch control and B. Not feel like I hit a brick wall when hitting rev limiter while drifting?

[steve99]

Originally Posted by Hybrid707

Hello, as the title says I was wondering if there was any way to change the rev limiters to spark cuts instead of fuel cuts so I can A. Possibly shoot a flame with launch control and B. Not feel like I hit a brick wall when hitting rev limiter while drifting?

Fuel cut rev limiting is coeded into ecu, even with ecutek is not changeavle to spark cut.


Most modern ecu use fuel cut as its vetter for emmissiobs than fuel cut.


You can however use ignition retard to limit rpm to achieve a soft rev limiter prior to the fuel cut. Its also possible to lift the fuel cut to a higher rpm. Neither will acgive flames at rev limit though


But you can achive a limiter that you can jist drive at without harsh fuel cut

[Kodename47]

Originally Posted by steve99

FYou can however use ignition retard to limit rpm to achieve a soft rev limiter prior to the fuel cut. Its also possible to lift the fuel cut to a higher rpm.

I'm fairly sure you could mimic an ignition cut by running a very sudden ignition retard at the limit rather than the gradual soft ignition retard limiter you're on about.

Just set it to 25-50 RPM from full advance to full retard and see what happens Probably worth cutting some fuel out at the same time mind.

[ls1ac]

Wait a moment, you want to turn off the engine (either by fuel or ignition ) and not loose power??

[steve99]

Originally Posted by Kodename47

I'm fairly sure you could mimic an ignition cut by running a very sudden ignition retard at the limit rather than the gradual soft ignition retard limiter you're on about.

Just set it to 25-50 RPM from full advance to full retard and see what happens Probably worth cutting some fuel out at the same time mind.

My current ignition retard limiter goes from full advance to -30 in 100 rpm, limits powe\rpmr but zero pops or bangs or flanes.

[tomm.brz]

Mine is more extreme like kodename said, - 35 of retard with a hysteresis of 30rpm
It just bounce back and fourth very quickly while at limiter but no appreciable pops
But i also have the fuel cut... What happens if we do not apply the fuel cut but only the ignition cut?

[erebuswarrior]

From my testing nothing happens. I've tried leaving fuel cut rev limit at 7600 and hitting max retard just before it at 7500 and even as early as 7000, nothing. It skips right past it to the fuel cut rev limit. I think there's more then just the base map influence top end timing. I believe when I logged, it would hit -20 total timing before the fuel cut rev limit, and still pass up the full retard at 7k and start rev limiting at 7600. I haven't played around with it in awhile, but turning off fuel cut is risking engine damage unless we can get retarded timing to actually rev limit. Actually, I wonder if setting hysteresis to 0 or 1 and -20 (or more) retard, this should make fuel resume immediately as rev limit hysteresis is how many RPM's it must drop before resuming fuel injection. I wonder if that would risk engine damage though, because it could cause over revving maybe? Although it looks like rev limit fuel cut resume is managed by manifold pressure, I don't see a rev limit hysteresis for the main rev limiter. LC and FFS have hysteresis though. Gonna set that to 1 and see what happens.

[Kodename47]

@erebuswarrior are you editing the correct ignition timing table?

[erebuswarrior]

Originally Posted by Kodename47

@erebuswarrior are you editing the correct ignition timing table?

Ignition Base Map VVT On? Here's my results from trying the below. It actually starts basically rev limiting and wouldn't go past 7k, but no pops. Looks like -30 isn't enough.

https://datazap.me/u/naroean/log-157...g=0&data=14-20

[gt7877]

+1

[solidsnake11]

Originally Posted by erebuswarrior

Ignition Base Map VVT On? Here's my results from trying the below. It actually starts basically rev limiting and wouldn't go past 7k, but no pops. Looks like -30 isn't enough.

https://datazap.me/u/naroean/log-157...g=0&data=14-20

That should make your header a bright orange in a short period of time.