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911st 911st is offline
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Join Date: Jan 2004
Location: Sacramento
Posts: 7,269
As to BOV's the stock plastic BOV from Bosch as used on the 91-4 C2 Turbo is sufficient. They cost about $45 each I would guess and are about 1". You could put two on if you wanted.

However, I would consider a Synapse Engineering BOV. Them make a 1.5" and it is in a class of its own as to function. It can improve your turbo spool time.

The best place for a BOV is as close to the throttle plate as possible so that would be after the intercooler and before the throttle plate. However, there is no reason to not put it between the turbo and intercooler and many find this easer to accomplish.

The other side of the BOV is if you run a MAP style injection it can just vent to atmosphere.

If you do something like a MAF that meters the air quantity before it enters the turbo, you would want to have the BOV deliver its blow by back to a point after the MAF sensor and before the turbo.

Tial makes great BOV's to.

Get comfortable with the search function here. There is a couple of threads on intercoolers or intercooler cores that show great pictures of plumbing a Carrera intake EFI motor.

One suggestion. If you keep you cams, and I think the stock cam is a good TQ cam, you would benifit from opening up the intake ports.
Old 06-21-2010, 04:21 PM
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