Rev Limit for Turbo E36 Drift Car

[nicfabb]

Looking for some insight on rev limit settings.

I currently am running a fuel cut limiter setup, however the rev limit seems to make the car fall on its face in Drift and makes it lose wheel speed which can be problematic in certain scenarios such as drifting on a bank. 

I have a friends limiter settings that is consistent, does not impact wheel speed and seems a lot better suited for what i would like for a rev limit though it is an ignition cut versus fuel. 

Can I switch to his settings without issue or will it not be a good idea if mine is fuel cut or does the rev limit not really matter to the overall tune or safety of the engine? Both engines are the same in Max RPM limit as well as the same valve train, his is just more constant and not like mine that feels like it hits limiter then falls off then recovers back to limiter and falls off again like it is cutting out for far too long.

below I have attached my settings which is the fuel cut limiter and my friends is the ignition cut as well as my current tune

Ive heard Fuel cut is not good for a drift car but Ive also heard the same with ignition cut 

New Dyno Tune.pclx

[David Ferguson]

The critical difference between those two limiter settings, is the "Limit Ctrl Range" and "Hard Limit Activation".   Consider trying 300/100 instead of 50/0 and see how that feels.    You might also find the "Start Cut (TPS 100)" will affect the feel as well.

[nicfabb]

I’ll try it out! But would it be a bad idea to just run his limiter if I were to switch to his settings or do you think it would have a negative impact to switch from fuel cut to ignition cut? 

[K4Tuning]

10 hours ago, nicfabb said:

I’ll try it out! But would it be a bad idea to just run his limiter if I were to switch to his settings or do you think it would have a negative impact to switch from fuel cut to ignition cut? 

Just a little note on this, Its almost always more beneficial/safer to use an ignition cut vs fuel cut. The reason is if fuel cut is used, its doing just that, cutting fuel. So this leaves the possibility of a lean condition. Using ignition cut is safer because when the ignition is cut, the fuel is still present. Hope that helps.

[koracing]

Be careful there though as ignition cut can be much harsher on vehicles drive train/valve train (like SR20 rockers).  A fuel cut isn't an enleanment - it drops fuel cycles completely so it's not that there is *some* fuel in there causing a lean condition per-se, the injector actually doesn't inject on a cycle or some percentage of cycles so no fuel in the combustion process at all when it's cutting a particular injector.  At least this is my understanding and why I usually use fuel cut instead of ignition myself.

[nicfabb]

@koracingi agree, so my question is since my friend has an identical engine to mine with ignition cut and mine is fuel cut I should be able to just switch to ignition cut without issue since it is only controlling the rev limit and not messing with any other parameters for the tune itself that was something I was curious about before 

[koracing]

@nicfabb In a drift scenario I can see wanting to use ignition instead as it does tend to keep the motor going and on boost - but I would try to make it as soft of a cut as possible that effectively accomplishes the task of holding rpm.  I can't give you specific recommendations for that personally, however.

If your friend's car is also drifting and it's working well for him, I don't see a reason why you couldn't start there.

[Adamw]

The cut decay time is the main issue.  With it at 400ms and the start cut at 60% it means any time you even just kiss the limiter it is going to be cutting at least 60% power for nearly half a second, this is the reason it is "falling on its face".