[FDTT]

yes a BOV on the stock motor and air intake system will hurt your performance, and may cause the car to not even run.

The car has a MAF that meters fuel to the engine, when you dump air to atmosphere that was suposto be metered into the a/f ratiopn in the engine you have a rich running situation. This will urt the performance.

I think the best way to do it is get a cone intake filter, aftermarket BOV with recirculation adapter and plub it back into the intak. That way the MAF is doing its job properly, car is performing well and you will still hear it, but it wont be as loud as an open dump.

I recomend the HKS SSQV BOV, ive had alot of good experance with them.