<VV> Re: turbo mufflers, was are turbos worth having?

[Bill Brafford]

you are correct eric in that GM put forth a great deal of effort to get the 
exhaust system to match up to the turbo. It was found during testing that 
the tailpipe must be 9 in long to be "reasonably tuned"  There is a critical 
balance between backpressure and acoustics. Any changes from stock will most 
likely effect performance, for the worse.
The above along with other developmental topics on the spyder was written in 
an SAE paper dated June 11, 1962 titled "The corvair turbosupercharged 
engine" this was presented by Jim Brafford, my uncle.

Bill Brafford
63 spyder vert



To: "Rick Loving" <ral1963@earthlink.net
  "'Louis DeRobertis'"
  <louis@suffolknet.org>, <virtualvairs@corvair.org>
From: "Eric S. Eberhard" <flash@vicspdi.com>
Subject: RE: <VV> Are Turbo Vairs worth having?

Mufflers were restrictive on purpose ... imagine trying to build pressure
in a chamber ... the more flow out of the chamber, the harder to build
boost.  The mufflers were set to be the "correct" restriction given the
input (carb).  If you change to a less restrictive muffler and that is all
you do, you will certainly not have good boost.  If you also increase input
(such as Weber, etc) then you need a free flowing muffler ... but you are
in the experiment zone.