Turbo/wastegate questions - K24, WG Spring etc.

[<isham-research.freeserve.co.uk@pop.pol.net.uk>]

> Since I've never actually cracked the wastegate open, are there any diagrams
> of a wastegate blowup.  did not find any in Bently or SJM great site.  How
> difficult is it really to replace a spring or install a shim?  I'm willing
> to try new things, but not if they are likely to cause irreversable harm.
> Javads adjustable cap seems to be a pretty good idea, but I can't even tell
> how it would work without seeing a full diagram of a wastgate assembly  Got
> pictures in my head from what everyone's saying, but..any diagrams?

No, fiddling with the top of a wastegate is easy and utterly risk-free.
Just unscrew the six nuts and the wastegate cap will slide up under
moderate force - easily controlled by an adult hand.  Shimming should be
done in 1mm or 0.5mm steps - a stock ECU boost cut-off is quite sensitive.
I've seen several cars where 2mm was too much for the stock ECU.

> Regarding Phils last comments though.  Have I lost some of my low end boost
> by Bypassing WGFV with pressure regulator which I understand is a popular
> and inexpensive mod.  Would it benefit to tee the original line back in
> using a one way valves so you get the vacuem lift on the low end,  and the
> needed bypass on the high end(trying to explain what I think againg without
> actually knowing what one of these looks like taken apart).

No, don't mess with it.  Under WoT the ECU is very active in managing
boost - any non-linearity you introduce will defeat its efforts.

> My apologies to those who sell the mod kits by the way, as I'm sure they are
> worth it.  Some of us just can't afford or justify expensive chips, new
> turbos and the like.  I'm not a racer, don't have the money or time - maybe
> some day.  Just want to get the best performance available without spending
> more than the car is actually worth.   I learn from the expert advice on
> this list and other sources, and then I'll apply what I've learned if
> prudent as a home mechanic/hobbyist.

I don't think the ECU/spring modifications, as produced and sold by
various parties in the USA, are 'expensive'.  For one thing, they're
100% reversible - not the case with, e.g., hybrid turbos and ported
heads.  In my experience, most buyers want stock cars - highly modified
ones are very hard to sell.  Secondly, these modifications retain the
best attributes of the car - especially its driveability.  I've just
bought Scott Mockry's MAC14 kit (despite being quite capable of burning
chips myself) for this reason - I will be able to sit in High Street
traffic and not stand out, but I'll still be able to burn off BMW M3s.

As regular readers will know, I _love_ stealth.  Enquiries at VAG UK
have revealed that my MC-2 MAC14 Type 44 quattro Avant is one of _FIVE_
imported to the UK in 1989/90.  I've taken the badges off the back and
replaced them with:

           "Audi 100 CC         oooo           Avant"

Which is the badging for the base non-turbo non-quattro model - they
sold several thousand of _those_.

--
 Phil Payne
 UK Audi quattro Owners Club
 Phone +44 7785 302803  Fax +44 870 0883933