joecitizennn

I dont do it very often, but every once in a while I dip into the redline and bounce off my rev limiter when shifting. Is this harmful to the engine? The rev limiter is to protect the engine, what kind of rpms are required to cause engine damage to a stock 2.5 944 engine? 8-9k rpm?

rgs944

I have had my car for 20 years and did not know it had a rev limiter. I am sure someone knows when they started putting these in P cars?. Depending on what people say on the follow up, I think I might test mine out sometime to see if it actually works.

john durdin

BOOOM #%&*#@

joecitizennn

Like I said I dont very often hit it, usually I watch my tach and shift before red, but when you are going over 100 you are trying to keep your eyes on the road. When the rpms hit 6500 its like the fuel and fire cut off till the needle drops back down to 6000 and then the engine kicks in again. Just wondering what the actual mechanical limits of a stock 2.5 are. Surely someone knows.

jsaindc

I have hit it a couple times autocrossing. I back off right away and so far no problems.

rgs944

Do all 944's have a rev limiter? What about the 924's?

Engenia

I've just re-built an '83 944 with custom pistons to take it up to 2.7 litres & a CR of just under 12:1 (it'll run on LPG). The standard exhaust valve to piston clearance is generally 0.080" - 0.100". Unless you've had your head shaved, that'll be about the clearance in the standard engine. When hot, that clearance shrinks. When spinning fast, the conrod stretches. So everything is conspiring against you.
My exhaust clearance came out at 0.074", which had me worried, until I talked to Rod, of Rod Smith Racing. He builds engines for the local 944 Challenge Cup, & has used as little as 0.040". The only problem these engines have, is when a lower gear is selected at too high revs. At about 10,000, the exhaust valves get bent.
So it turns out, my worries were unfounded, and so are yours. If Rod is to be believed, a standard 944 engine could spin towards 10,000, and the valves would survive it. Hitting the limiter isn't going to bother it in the least.

J Berk

I agree.

In my first DE season (now three years ago) I was hitting the limter often....found I was focusing on steering more than shifting.

It's there to stop you from over-revving under normal (proper gear) conditions.

Agree also that if you're near redline in 4th and downshift to 3rd you're F'd !