Most setups I see place it after the intercooler , just before the throttle body.

You want it as close to the TB as possible to minimize the risk of compressor surge. If the air flowing through the pipes has to reverse direction to get back to the BOV, it could lose some effectiveness, and even increase lag. But in practice, you probably wouldnt even notice either.

i've had it in both places. never noticed a difference...



i just put it where it fits. but like mazdaspeed 7 said, reversing the air can be problematic in thoery. so if you got room, as close the the TB as possible.

Re: IS anything wrong in putting the bov before ith intercooler
 

sorry to jump in ur thread here what do most people run air to air intercooler or air to water? does size of the intercooler help effiency?