[V8] Re: '93 5-speed writeup

[DasWolfen at aol.com]

In a message dated 3/25/04 8:50:33 AM Eastern Standard Time, 
David.Coleman at blackrock.com writes:

> This morning I was gazing coffee-less at my tach and thinking about that 
> 5800rpm rev limiter thing -- I think I must have been misreading your tach the 
> other night.  The third-gear limiter still seemed to come on early, but 
> probably closer to 6100-6200.   And even though I took it past 6300, it didn't hit 
> the limiter in 1st or 2nd.  So the killjoy still seems to be there.
> 
> In the interest of science, I set out in search of the limiter on my car, 
> and reached 7300 in 1st thru 3rd before chickening out and upshifting.  No 
> limiter so far... and that's pretty deep into the red, which is why I've never 
> been there before.
> 
> Maybe this is part of the PT/ABZ ecu difference -- or to be pragmatic, maybe 
> VAG thought it was in the best interests of the 4.2 to limit it where it 
> does.   I wonder if Ned's 4.2 chip nixes the limiter?

  I'm gonna go out on a limb and say what you were seeing was probably a tach 
issue. There's no way for a V8's ECU to have any idea what gear the car is 
in. Even in the automatic cars the info all flows in one direction...Motronic to 
Trans ECU.

 The only other possibility I see is the Motronic anticipating the 
approaching redline, in the two lower gears things could be happening faster than the 
computer is programmed to respond with the limiter and in the two higher gears 
the rate of RPM increase isnt fast enough to cause it to respond early.....that 
4.2 does pull pretty hard in 3rd huh! =0)

 The IA chip didn't seem to change the limiter in my old 1990...it was 
consistant at around 6700. Not that I think its a good idea to be watching the tach 
that closely when my foot is buried to the floor. 

Keith