Re: bmw-digest V9 #594

[Bliq@xxxxxxx]

In a message dated 11/26/98 2:32:14 PM Pacific Standard Time, owner-bmw-
digest@domain.elided writes:

<< Isnt this covered by the  rev limiter that is engaged  when the revs go
 over the certain limit.   (fuel cut off will stop a over rev dead in its
 tracks.  No fuel, no more rev , it is that simple)
 
 Mark >>
Actually, this is not accurate.  If you are going 70 mph and you accidentaly
shift from 5th to 2nd instead of 4th, you will overrev.  The rev limiter will
save you when going up the rev ranges(engine turning the wheels against the
road) but if you misshift, the wheels turning against the road drives the
engine and the revs go up a lot and there is nothing the rev limiter cutting
off fuel can do.  Think of it this way, if you were going 90 mph and you
turned off the ignition and therefore fuel delivery but the car was still in
5th gear, your engine would still be spinning at say 4500 rpm.  Now shift into
2nd and watch the revs go up to 9000- over rev condition without any fuel
delivery.

Make sense?

Rob
89 M3- 7800 rpm rev limiter

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