Anyone know how to disable the rev limiter in a stock S4 ecu?

 

There's someone that advertises in the back of Sports Car. Other than that, no.

 

I've been looking for 3 months and still no luck. If you find out, please let me know.

 

The ECU in my car was reprogramed by Speed Source, but we were under the impression that there was a single component on the board that could be disabled to get around it. Looks like that is not the case

 

Here is the ad in the back of SportsCar verbatim:

RAISE THE REV LIMITER IN YOUR CAR'S COMPUTER FOR ONLY $100. Why pay more? RX7, Miata and most foreign cars. This is the most power that you can gain for only $100.00. Contact Keith (305) 232-0460.

 

Thanks, I had seen that ad a number of months ago and didn't think of trying them as I can't believe that the mod is that difficult and wanted to see if I could do it myself. I will call him a little later today and after I talk to him I will let everyone know.

 

???soo...

 

You cannot disable the rev limiter in the stock ECU without reprogramming it or replacing it with an stand-alone EMS.


-Ted

 

I suppose a good question would be "Why do you want to disable the rev limiter?"

Stock intake/exhaust sort of falls flat around 8k, if you go much above 8k you need a clutch/flywheel blanket or shield, and if you go much higher you'll start running into eshaft flex & such.

If you've done the intake/exhaust & fuel system work and are running a race vehicle, then yes, disabling it makes sense. By this point, most people have replaced the stock ECU though.

-=Russ=-

 

My ECU is on it's way back from getting reprogrammed. The explanation I received from several sources is that S4 and S5 ECU's start getting ignition break up about 7800 RPM (soft rev limit). I have been experiencing this phenomenom for quite some time. I have the dyno charts to prove it.

The other benefit of removing the rev limiter is for race applications. If you can rev to 8500 RPM, you may not make more power but if can save from having to shift up and then down at a particular part of the track. Best example would be between 10A/10B and 11 at Mid Ohio.

I am racing at Mid Ohio this weekend and I will let everyone know how it turns out.

 

Just a follow up on the ECU mod I had done. I raced this weekend at Mid Ohio, and the rev limit removal worked wonders for my shift points. The car does not stutter above 7800 anymore either. In fact it revs all the way to 9000 without hessitation. I highly recommend it for those who track teir cars.


Pauly D

 

Paul, can hitting the rev limiter induce the limp mode we were talking about?

 

I have not heard rev limit causing limp mode. I will look into it.

 

Chris,

Looking at the control system trouble shooting chart, the only inputs that would cause limp mode symptoms ("basic fuel injection amount and ignition timing fixed")is a failed oil metering pump or pump sensor, or a bad airflow meter. There are quite a few other fail safe modes for failed input devices, but the ones I mentioned are the likely causes. Keep in mind you might have a short or open int he wiring harness as well, especially since the fault is intermittent.

Pauly D

 

Well...I replaced the airflow meter with a new one last year, used two different OMPs, reshimmed the ones I have, tested the sensors, tried three different ECUs and two wiring harnesses. I'll keep flipping the switch I guess. Thanks!!!

 

Hey pauly...what did you do to remove the limiter? I don't see where you actually said what you did? I don't really need 9k but still it'd be nice to be able to go a LITTLE further than 7700.

Kiyo

P.S.
PM me I'll prolly see it faster .