Bypass Valves
Jim Lill (jpl@vectorbd.com)
Fri, 14 Aug 1998 16:21:40 -0400 (Eastern Daylight Time)
After driving for a week with a vacuum/boost guage it becomes obvious why
a manual trans. car needs a bypass/dump valve. Scenario: wind up thru 1st
gear and while at max boost, shift into 2nd. What you see is the boost go
to max vacuum (unless you "board shift"). This means that the compressor
is blowing into a closed door, the closed throttle and starts spooling
down. Solution is to add a $43 bypass valve that vents the compressor
output while the throttle is closed and there's vacuum.
see: http://www.turbonetics.com/catalog/bypass.html
The quickest way to install this would be to tee into the aux air valve
hose and vent into the atmossphere (there may be oil mist so not the
airbox).
The correct way would be to enlarge the aux air port on the intake tract
to 1 inch and tee in there. The outlet should go into the inlet side of
the compressor, after the air flow meter. Correct also means more
difficult and more work!
-Jim Lill http://www.vectorbd.com/users/jpl