mspiegle

reminds me of this time I was rolling down PCH and ran into a guy with a 500rwhp cobra. My eyes were completely lit up and excited. I followed him down an empty street and got up to around 5K rpms in first gear. We both nailed it at the same time and I wasn't even paying attention to my car, I was just watching as he left me like I was standing still. After a few seconds, I had realized that I forgot to shift because I couldn't hear my car over his crazy exhaust. We went at it again, and I still got creamed, but not as badly. I was probably hitting the rev limiter for a solid 4 seconds or so.

sublimate

I defer to John as the LH expert. My info came from the book "Bosch Fuel Injection & Engine Management" by Charles Probst, not from personal experience, so I can't vouch for it's accuracy. But given the risks I would certainly want to check for myself before running my boosted shark up against the rev limiter.

DFWX

The fuel starvation based rev limiter is hard on the motor if used routinely or often - and deadly if the car supercharged or turbocharged. The rev limiter does not tend to just cut off fuel, but cut it on - off - on - off rapidely - creating terrible over-lean situations and denotation potentials.
Like all manufacturers, Porsche sets its redline well below actual mechanical failure levels - and then puts the rev limiter 250 to 500 rpm beyond the artificial low limitations.
They have no choice or warranty claims would eat them alive.
Without excessively low redline and rev limiters, they'd have clams for the guy who starts his car in -zero weather with 40 weight oil in it, reving up and down to 7,000 rpm so it'd warm up faster (more likely, of course, it is his wife doing that - why do women do that?!!)
I'd like to know how to disable the rpm limiter completely.
Rather, I would like a "limiter" that shut the motor off if oil pressure feel too low or engine temperature when too high.
Mark

Vilhuer

This reminds of story I read once. In early seventies Ferrari tech gets a call from 365 GT 2+2 owner about cold start problem. Car sits outside and is driven all year round. Owner is having some difficulties geting it started in chilly winter mornings. This takes place in New York or some other part of USA where it get below freezing at winter. Mechanic gives owner advice to push gas to the floor few times keeping it there for couple of seconds.

Year after that workshop gets sued to court. Poor Ferrari could not take it anymore. Instead of first pushing the pedal to prime Webers and then starting owner had started the car and immediately pushed loud pedal to the floor rewing engine to about 8000 rpm to delight of the neighborhood. 4.4L V12 engine could take the abuse on every winter morning but finally other parts could not. Flywheel and clutch exploded throwing parts through bellhousing. This lead owner to sue workshop for bad advice.

This should be true story and there are court documents to prove it. And yes, owner was woman, not that it matters that much. I'm sure some men can do worse.