High RPM between gears

[Huw Powell]

here's some more thoughts on this.  I re-experimented with it last night
to remember.  If you lift off gently as you're abou to shift, ie stop
accelerating but maintain speed, *then* press the clutch, no rpm rise. 
This has an odd effect, like much of what the 90Q is like to drive, of a
sort of "traffic calming" - you learn to drive the car in a smooth,
mellow fashion.

I think it is the dashpot.  it stops the throttle from closing the last
few degrees quickly.  So if you are accelerating and in one fast move
lift right/push left, the butterflies are still open a bit and the
unloaded, spinning engine can get some extra revs for a moment since the
airplate drops a bit slower than necessary and you don't get to the idle
switch (which kills the gas) in time.  The gentle lift technique gets
you out of this "fiery" zone, lets the airplate drop a bit, so during
the "dashpot phase" the engine can't grab more air than is appropriate. 
That's my *theory* anyway, it is not tested, by, say, removing the
dashpot...

Other factors may be involved, like the high compression or turbo
engines having something else in common here.

> 
> >my 90Q does it too, I've been trying to observe it carefully... i
> >suspect something lets air that is not needed in for a moment after the
> >pedal is lifted.
> 
> Huw hits the nail on the head.
> This is done to reduce some "nasty" emission or another on gear changes.
> There is a damper connected just below the throttle that keeps it open
> slightly for a second or so.
> I have yet to remove mine so cannot say 100% that this will work but I think
> it will.
> 
> Kevin Phillips AIM "quattrohead"
> Western Massachusetts
> 1990 200q
> 1995 900 SET
> Cell 413 519 9034

-- 
Huw Powell

http://www.humanspeakers.com/audi/

http://www.humanthoughts.org/