quattro digest, Vol 1 #3540 - 15 msgs

[Dave Eaton]

finally, you agree....

have to say i chuckle at the comments about the lack of "optimisation" of
the rs2 turbo in the rs2, or that the "case" showing that the rs2 is very
poor below 3,000rpm vs the k24 isn't proven yet.

last time i checked under the hood, there was a name cast into the inlet
manifold.  wasn't "audi", iirc, it was "porsche".  and they sure as hell did
a lot more to the car than just plumb a bigger turbo in.  fact is that they
wanted more than 300hp, and in order to get it, without modifying
displacement, they went for a bigger turbo.  that comes at a penalty of
(comparatively) lethargic low-end response.  this is despite the changes
over the s2 (with aby) which comprised the map, the boost, the exhaust, the
inlet & exhaust manifolds, the exhaust cam and fuelling, the airbox and
intercooler.  ipso facto.

the result is a very strong 315hp, a great top-end and a lot of smiles, and
all cars quickly sold.  happy punters.

interestingly there is always someone (funnily, most often someone with
something to sell) thinking (or stating) that they can do a better job.
claims are easy, and cheap.  happy to see a product, and get some experience
of it.  any offers for an "optimised" rs2 turbo out there? ;-)

i'm happy with my rs2, happier with my k24 ur_quattro.  just don't tell me
that lag doesn't spoil the rs2, because it does.

i stick with my stopwatch in the meantime.  there is no fooling that...

dave
'95 rs2
'90 ur-q
-----Original Message-----
From: QSHIPQ at aol.com
Subject: RE: RS2 turbocharger

Certainly there are better out there, but pick and choose wisely folks, the
sacrifices big turbos have are in low end response.  Porsche did some great
homework that is dirt cheap in comparo to some of the better homework MTM
did.

I'd also encourage anyone to ADD DISPLACEMENT.  Displacement rocks turbo
maps.  At 2.6 liters, the RS2 becomes the k24 of turbos.

[snip]

Sounds like many could benefit from spending some money on a turbo dyno (yup
they have those).  Maps easily indicate how far "off" you are in sizing.  In
the world of choices, opening up too much top end almost always COMES at the
expense of low end.  I say if you don't ever need or will never need the
800+cfm, go smaller and get back the low end.

The basic recommendations for matching turbos is in several publications,
including Corky Bell's.  If you haven't taken a gander at a turbo MAP and
understand how it works, going BIG is a sell, not necessarily a wise
decision.  I've seen many a post here wrt "bigger=better" where the turbo
never gets to it's peak turbo CE.  Better ways to skin that cat IMO/E.