Biggest advantage for installing an aftermarket BOV is that typically, aftermarket units have a stiffer spring to hold the valve tightly to prevent leakage at high boost level, secondly some aftermarket BOV are adjustable (via turning of a nob or swapping out the valve springs) so you can dial down the exact pressure when the BOV should vent. Depending on the types and manufacturer of BOV, installation is typically very straight forward.Originally posted by dj villain
what are the advantages and disadvantages of getting an aftermarket BOV? and if i get one...do i just put it on and go...or are there other things i need to do? i'm new to subarus...so please help. i need all the info i can get..thanks also..how hard are they to put on?
Disadvantage - see MawviN comment.
Stock CBV (compressor bypass valve) is actually a very decent unit and it only experiences minimal leakage at around 16 psi or so. I would not recommand BOV as your first mod since aftermarket BOV does not provide any real hp gain.