RE: Macboom -Reply

[Dave Lawson <dlawson@digitalglobe.com>]

Mike,

>
>I will second that too...  Beyond 2.0PR, you better do things based on
>knowlege, not the addiction for more is better, cuz it ain't....  I can share
t>hat beyond 2.0 PR on a stock audi turbo, you are increasing the INefficiency
>of the turbo, and creating a huge back pressure wave on close throttle,
>decreasing the life of the turbo as well as the engine....

Doesn't the turbo bypass valve take care of this??By just dumping excess boost 
into the exhaust.
>

In closed throttle situations, the turbo bypass valve opens(based on intake
manifold  vacuum) and circulates boosted air, caught between the turbo 
compressor outlet and the closed throttle plate, to the inlet side of the turbo 
compressor. This re-rounted air helps keep the turbocharger spinning and
helps the on-off-on throttle transitions.

IMO, it is a good thing and I will be installing one on my ur-q this spring. Igor
had a great post a few months ago on how to plumb one into a 10V 5000/200 
TQ. And as QSHIPQ stated, the air should be re-circulated to the turbo inlet, 
not dumped.
-
Dave