Re: [s-cars] Re: tubular exhaust manifold and turbo options

[CaptMagu at aol.com]

In a message dated 3/17/04 7:12:13 AM, mlped at qwest.net writes:


>  At 250 hp, 2.5" is fine. Going to 3" at this power level
> won't get you much, if anything, other than a louder exhaust note. 300
> hp and you're definitely suboptimal with 2.5". For 400-450 hp, even 3"
> is on the small side.”
> 
That's what our cars were screamin at us while they were on the dyno. The 
wild noise coming from our exhaust was our 3" systems protesting at their 
overwork. Your car and my car are the only Audis I've heard do that. You know, that 
green car that you haven't driven in a while

> SECOND, vis-à-vis Audi's 2.7L twin turbo EM design and implementation,
> (a) if you have ever looked at the motors two cast & cased EM's, while
> the exhaust ports in the heads are "regular" sized, the three in each
> manifold squeeze into an extraordinarily small common exit/feed into the
> KO3/O4 hot side scroll.  (b) I believe the EM is actually enclosed in a
> second, probably insulating clam shell.  Are these just a packaging
> design problem for the twin turbo engines or a performance design goals
> as well?
> 
That probably has a lot to do with TEC building my turbo with a number 6 
hotside. With the recent enhancements I'm down to a boost threshold of 3200rpm for 
full boost at altitude. When I took my car to Sears Point last year my then 
threshold of 3500rpm at altitude dropped to 3000rpm at sea level. I guess I 
would be well below 3000rpm in my current trim. Woohoo.

Hap, woohooin in Evahboost, Maguire