PROBLEM: What controls the rev limiter

[FF_Mark]

My mates S2 RST rev limit seems to move around, some days its 6,000 and some say its as low as 5,000.

Any ideas guys ?

[Scott_R]

I fairly sure that its done by resisters on the ECU board. Are you sure ts deffinately the rev limit he is hitting and not over boost??

[FF_Mark]

He said it stops like hitting a brick wall, but just randomly http://www.turbosport.co.uk/images/smilies/blush.gif

[Scott_R]

Randomly when he is driving it hard or just anytime???

As if you accelerate slowly and build the revs up gradually you will get higher up the rev range than if you just floor it.

It could be the rev limit changing but i have never come across this happening, its normally something else.

[FF_Mark]

When he ragging it, don't think its been lower than 5,000, but it makes it hard to drive when the limiter comes in early at 5,000 when your not ready for it.

[Scott_R]

Is it chipped then, and what boost is he running??

Have you tried swapping your ECU with his??

[FF_Mark]

Its standard at the momemnt, although he wants to chip it once he can get it running cooler (another problem)

I will check what ECU he has and which one mine is and swap them if they are the same type.

[Threedoorboy]

is it making any boost? Mine had this problem and it was down to the fact that is wasnt making enough and would not rev above 5500

[Adam_Ash]

If its just like hitting a brick wall, it is probably one of the capacitors in the fueling ECU, mine does this and really fugged me up for TOTB2 Qualifying http://www.turbosport.co.uk/images/smilies/mad.gif Meant I couldn't launch it or even do Qtr miles properly!!

Should be that m8.

Oh, just remembered, mine also used to do something similar a while back. The Turbo to metering head boost hose used to suck in anywhere between 4500 and 6000 rpm. Was just like hitting a wall too. Used to collapse completely, but as you cant really see it when your driving, was very hard to diagnose.

could be one of these probs m8

[FF_Mark]

He's just told me that the car also sometimes cuts out whilts he's driving, the rev counter goes down to 0 and the engine cuts at the same time, then a few seconds later it starts back up if hes still rolling in gear. !!