To expand on that, BPV = by pass valve - recirculates air back into the intake BOV = blow off valve - dumps air into atmosphere
I just put my Forge BOV on and it works wonders. No more rise in rpm between shifts and it works perfect at idle. Nice sound too, but not too loud.
I'm thinking about just getting an intake afterall. I mean I love the stock look and stuff but.... ah, I don't know.
Do I need to be refreshed on Suby performance knowledge? I've always heard that CAI are about the last intake you would want on a WRX. It cools the air down, just to get warmed back up by the turbo. I've always read that stock airbox (w/ snorkus mod) is all anyone would ever need to do unless you have a front mount, and in that case you do a short ram, ONLY because the stock airbox won't fit. Am I correct on this info? I just always thought of intake as in the same department as BOVs. They both sound cool but can actually kind of hinder your performance unless tuned for. I know a lot of you have intakes on your cars and I'm not trying to bash or anything (I'd like a sweet sounding BOV at some point). I just want to know if this is indeed correct.
A proper cold air intake will probably be as good as or possible a tiny bit better than the stock airbox. A short ram (where the filter's in the engine bay) will decrease performance. As to the 'air gets warmed up anyway' thing: it's not like the air comes out the turbo at X degrees no matter what the inlet temp was. Cooler air in = cooler air out.
also remember the stock airbox can accept a large amount of hp ive heard of as much as 400hp on stock airbox.