Thread: BOV orientation
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JFairman JFairman is offline
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Join Date: Jul 2006
Location: S. Florida
Posts: 7,274
I remounted my BOV sideways, but I did a couple other things that improve drivability at the same time so it's hard to say if it made a difference.
Seems to work about the same, but my 25mm TurboXS "bosch replacement" BOV doesn't have a real light spring.
It does have some spring tension adjustment and it's easy to screw the top off to try lighter springs.

A BOV that has more surface area on the back side or vacuum line side of the piston would work better this way with a light spring because when boost comes on there would be more boost pressure pushing the piston shut from the back side.
The brass piston in the one I have has the same surface area on the both sides so mine needs a fairly strong spring to hold it shut while accelerating with boost.
There are so many aftermarket blow off valves to choose from these days... who knows which one would work best.

Seems the Synapse BOV is well liked by those that have tried it.
Old 12-08-2009, 09:14 AM
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