Re: Compressor bypass valve questions...

["Graydon D. Stuckey" <graydon@apollo.gmi.edu>]

On Sat, 18 Oct 1997, Jeffrey J. Goggin wrote:

> I installed one of the Bosch compressor bypass (aka "dump") valves on my
> 200q this morning and just returned from a brisk test-drive.  I must admit
> to being somewhat disappointed with the results: Yes, it works but it
> doesn't make *that* much of a difference, at least not on my only mildly
> modified car.  I think I understand now why Dave Head decided to sell his
> setup ... perhaps it'll make a bigger difference once I install the GS
> Racing 3" downpipe/exhaust system, extrude-honed exhaust mainfold and RS2
> turbo next weekend?

Jeff,

	I would admit that my 5KCSTQ's engine responds _alot_ quicker 
than a CIS-equipped engine, but I find that on my car, with the Redline 
in the transmission, and a well lubed shift linkage, I can shift pretty 
quickly, and my boost doesn't drop much at all between shifts.   Maybe a 
couple tenths of a second wait to get back up to full boost.   If that 
were cut in half, that would be barely noticeable on a quarter mile run I 
think.   This definitely falls into the "last tenth" category IMHO.   
Especially with the small bore bypass valve that is typically used.   If 
it were a 2" bore (or more) that flowed air _very_ smoothly, I would be 
more anxious to try it out.

Later,
Graydon D. Stuckey 
****Standard disclaimer.****
Nothing I have said should be construed to mean anything you think I 
might have said in any way whatsoever.