Re: Bypass valve effectiveness?

[QSHIPQ <QSHIPQ@aol.com>]

In a message dated 97-11-06 13:48:19 EST, you write:

<< 
 But that's exactly what I was talking about....  if I do not release the
 throttle all the way during shifting, the compressor keeps spinning and
 there is no pressure spike in the intercooler.  I mean is there any
 _other_ reason for the bypass valve? 
  >>
You don't need to go anything more than Manifold vacuum to get a spike,
graydon.  That doesn't mean closed throttle necessarily, you reduce it, you
don't eliminate it.  If you are spinning a turbo in the 2.0bar range, you have
put unecessary load on the turbo bearings and cold wheel when NOT using a
valve.  Just about every production turbo car uses them after 1989.  A simple
and effective weapon to extend turbocharger and turbo bearing life expectancy.

HTH

Scott