WG connection, EM design

JShadzi at aol.com JShadzi at aol.com
Sat Dec 7 16:40:56 EST 2002

[ Picked text/plain from multipart/alternative ]

What is the advantage of having the wastegate exhaust source come directly
from the
individual cylinders, rather than after they are combined, in this pic:


This is assuming I am understanding what the plumbing is doing.>>

Ken, its tough to know exactly what the user was doing from this picture, but
that looks an awful alot like the Audi Sport anti-lag system, where intake
pressure is vented back through the turbine instead of going to atmoshpere to
keep the turbo spooled.  If so, bravo, that's a trick and very nice piece to
have on a turbo car, especially with a large turbo and high hp.

If in fact the above was simple for wastegate purposes, I'd say it was a big
waste of time and work, and I can't imagine that log manifold helps control
(or flow) exh. manifold pressures any better than a well placed runner in the
collector.  Frankly, there just isn't improving on the simple design, granted
whenever the transitions are smoother, there is better flow.  Here's what I
came up with, I have rock solid boost, simply spools up and the needle is
rock solid all the way to 7krpm, up to 20psi so far:

<A HREF="http://80tq.com/images/inside_flange.jpg">http://80tq.com/images/inside_flange.jpg</A>

Jim did a good job of this too:


> <<In the Maximum Boost book, typically wastegates are connected after the
> collector, and the more of a "Y" shaped fork between that turbo and
> wastegate, the better.>>

Yes, Corky's analysis is right on IME, no need to get any fancier than that.


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