catback exhaust heat retention?

[JShadzi at aol.com]

Come on, you want to wrap your whole exh?  I'd like to see the dyno results
of that  =)  Wrapping the downpipe is reasonable, but the whole exh. seems
like overkill, esoteric as you say.

Granted, one aspect of exh. dynamics was presented yesterday, bottom line,
its still about flow, its still about back pressure, and if a turbo has 4 or
5 psi of back pressure at its outlet, then that reduces the pressure
differential with the exh. manifold, and thus less boost and flow.  IME, in
any performance turbo application, you can't go wrong with 3", the difference
in even a 5kt is dramatic, and those have 65mm tubing, about 2 3/8".  Corky
provides a very general guide line with his graphs, they are simplyfied, I
wouldn't take them for gospel.

In turbo cars, the turbo is the equilizer in terms of response, etc.  You can
take a gutless, NA multivalve motor (ala 7A), bolt a small turbo on it, and
have a torque horse, despite all the suttle exh. tuning variations.  For me,
if I'm going to spend the money on an exh. system, I want to make sure I
never outgrow it, I'm shooting for 400+hp, so that is a concern.

Javad
80tq.com


<< If we don't want our exhuast gas to lose heat and slow down in the pipe,
would it be
 beneficial to use some header wrap on the exhaust to keep the heat in?

 Or, if that will cause a fire or something, maybe some type of coating to
help retain
 heat?

 Granted these are esoteric options, but I'm just curious if they will help
anything.
 Maybe Eastwood Company or someplace like that has some type of treatment that
 can be applied at home.

 I believe the "quick rev" 2B downpipes are ceramic coated.

 I have another question:  I know you can get mandrel bend sections from
various
 suppliers.  Can you get a tapered section, like for the downpipe "at" the
turbo?

 Graydon's downpipes are like the 2B ones in that regard, I believe.  I'm
wondering
 how they are made.  Split, squished at one end, and welded?

 Thanks,

 Ken

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