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Hitting rev limiter...

Posted: Sun Apr 26, 2009 5:11 pm
by mbelle
...interesting what Martin Brundle said about F1 engines hitting their rev limiter - does hitting ours cause any(/similar) damage to our engines???

Re: Hitting rev limiter...

Posted: Sun Apr 26, 2009 5:55 pm
by Nige_RS4
mbelle wrote:...interesting what Martin Brundle said about F1 engines hitting their rev limiter - does hitting ours cause any(/similar) damage to our engines???
That's the whole point of the rev limiter ... to prevent damage!

Mind you, it isn't foolproof, as if you were to change down a gear by accident instead of changing up then the engine would rev beyond the limiter and the ECU would log something along the lines of "warranty void" (I'm not kidding, I saw it on an S4 I was looking for a friend a couple of years ago).

RE: Re: Hitting rev limiter...

Posted: Sun Apr 26, 2009 6:08 pm
by Contigo
That's a tad wqrrying! :D

RE: Re: Hitting rev limiter...

Posted: Sun Apr 26, 2009 9:07 pm
by TopBear
Porsche are notoriously strict on this.

They say that hitting or bouncing off the revlimiter on acceleration is fine, and these are logged as 'Level 1 over-revs', and the ECU logs each of these, every time its done, however if you commit a single 'Level 2 over-rev', which can only be done by e.g. 'accidently' going into 3rd instead of 5th whilst accelerating, or forcing a downshift when the revs are too high.....then your warranty is voided instantly. No matter if your car is 5 mins or 5 years old

Re: RE: Re: Hitting rev limiter...

Posted: Sun Apr 26, 2009 9:40 pm
by Rs4Fan
TopBear wrote:Porsche are notoriously strict on this.

They say that hitting or bouncing off the revlimiter on acceleration is fine, and these are logged as 'Level 1 over-revs', and the ECU logs each of these, every time its done, however if you commit a single 'Level 2 over-rev', which can only be done by e.g. 'accidently' going into 3rd instead of 5th whilst accelerating, or forcing a downshift when the revs are too high.....then your warranty is voided instantly. No matter if your car is 5 mins or 5 years old
They call it the "money shift". :D

RE: Re: RE: Re: Hitting rev limiter...

Posted: Sun Apr 26, 2009 10:58 pm
by no_RS
Over-revving on the downshift can cause a lot more problems than just the engine, an ex-colleague of mine downshifted a rental car on the motorway 6th to 2nd (haven't got a clue how he managed that), the electrics were never the same again..

RE: Re: RE: Re: Hitting rev limiter...

Posted: Sun Apr 26, 2009 11:03 pm
by rikrose
What Martin Brundle said was that the engine run lean up at the top. They do this to try and keep more of the power available when going at 18,000 rpm. since our cars don't get anywhere near that, they don't need to.

Re: RE: Re: RE: Re: Hitting rev limiter...

Posted: Tue Apr 28, 2009 12:22 am
by MilkybarKid
[quote="no_RS"]Over-revving on the downshift can cause a lot more problems than just the engine[quote]

What do you mean???!! They do this in Fast and Furious type films all the time! :P

RE: Re: RE: Re: RE: Re: Hitting rev limiter...

Posted: Tue Apr 28, 2009 8:42 pm
by no_RS
The alternator also gets over-rev'd, as this generates the power for all the electronic stuff in the car, may produce a power spike/surge/transient which could damage all the electronic bits.

As for the movies, so long as the cars worked whilst they were filming who cares :D