No subject

by stepping in to regulate the WGFV. Increasing the
duty cycle of the WGFV increases boost by reducing the
pressure in the lower chamber of the WG. The spring is
still holding the WG closed but is assisted now by the
WGFV restricting flow to the lower chamber. In this
throttle range, 2 boost maps are used. The lower map
gives the pressure at which the threshold at which the
WGFV starts to regulate and the upper map is the
target boost the ECU is aiming for.

If we are all on the same page about the basics, I
think the problems get easier to understand. I see 3
cases.

A) baseline pressure is above the boost target  map =
baaaad. The ECU is not in control of boost anywhere.

B) baseline pressure is between the lower and upper
limits. If the spring is set too hard, you probably
won't see smooth boost regulation = poor driveability.


C) Spring set lower than the boost regulation
threshold = safe but sub-optimal performance.

I think what I am looking for is a spring setting in
B, just a little above the lower threshold. This way I
get a high baseline boost, minimal WG creep and still
get good ECU regulation.

My $0.03
Rich


--- Mark Strangways <strangconst at rogers.com> wrote:
> If you can see the Allen head of the screw that
> adjusts the spring seat thru
> the un plugged hole at the top of the waste gate,
> then the screw has likely
> been adjusted. No for sure, but my S4 had a thin
> steel plug covering the
> hole.
>
> Due to my software, and waste gate spring combo I
> was advised to back mine
> out to 2 turns after it contacted the spring seat
> (done thru feel). But I
> counted 13 turns to fully seated as a factory
> setting.
>
> So what that means is, screw the Allen screw in till
> it bottoms then unscrew
> it 13 complete turns.
> I have no idea if this same setting applies to all
> year model combinations,
> but it may be a start point for you.
>
> As to if it's bad for the car !!! If the ECU cannot
> modulate the boost /
> overboost of the turbo then I would say it's bad
> chipped or not. Anytime you
> increase boost you increase power, provided you
> haven't superheated the air
> and retarded the ignition timing due to the
> increased boost.
>
> regards
> Mark
> ----- Original Message -----
> From: "Sean Douglas" <quattro20v at telus.net>
> To: <s-car-list at audifans.com>
> Sent: Friday, May 23, 2003 10:33 PM
> Subject: [s-cars] Wastegate Spring
>
>
> > I've heard that modifying or tightening the
> wastegate spring increases
> > boost but does this actually do anything for
> power? I read somewhere
> > that modifying the spring without software is bad.
> >
> > Since I'm the 3rd owner of my car, is there anyway
> to tell if the spring
> > has been replaced or modified?
> >
> > Thanks,
> >
> > Sean
> >
> > Sean Douglas
> > 1997 Audi S6
> > 1990 Audi 90Q20V
> > Surrey, BC
> > Canada
> >
> > _______________________________________________
> > S-CAR-List mailing list
> > S-CAR-List at audifans.com
> >
> http://www.audifans.com/mailman/listinfo/s-car-list
>
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