BOV MOD [Archive] - CT Subaru Community

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C-Rex

11-25-2006, 10:53 AM

Anyone ever thought of this?

I was unpacking some stuff from the move and I found the OEM recirc valve from my old WRX. I was looking at it and had a thought: why buy a aftermarket BOV when you can just make one out of your stocker?

Pull the BOV off the car. remove the two screws that hold the piece that connects to the hose. use a dremel or whatever to grind the fit-key (the little notch that makes it line up a certain way) off. Don't mess up the spot where it seals. Screw the piece back on upside down. Get something to plug the intake recirc hose, and re-install the valve. Tada!! now you have a BOV.

I know that some people get aftermarket stuff because it holds boost better once you start upping the psi, but most do it just for the sound. If you're one of these, this is a good way to save $200-300.

Personally, I think the atmospheric thing gets annoying after a while, but I'm gonna try this on my old BOV just to see if it works.

fireball_jones

11-25-2006, 01:28 PM

It works, I'm pretty sure there's a write-up on scoobymods about it.

brent

11-25-2006, 02:47 PM

bad idea, and search ;) if it can be done the n00b has done it...and no its NOT pretty haha

aftermarket bovs DO NOT hold boost better than the stocker and most leak unless u buy the expensive race versions (i believe hks has one NOT THE SSQV THO) the stock bov seems to stay open a little on idle which is bad news.

C-Rex

11-25-2006, 03:02 PM

iwanbo

11-25-2006, 04:07 PM

Listen to Brent, he's the local BOV master.

brent

11-25-2006, 05:11 PM

I noticed that the valve has a small gap in it when it's closed. and yes, a good aftermarket bov does hold boost better because the tension is usually adjustable. My stock BOV leaked alot when pushing 20+ psi but a TurboXS type H with a few shims held it just fine.

wrong again, most aftermarkets leak below STOCK boost even, and if u DO adjust them tight enough to NOT LEAK then you get TOO MUCH COMPRESSOR SURGE...u want cool sounds or a turbo that works properly? stock bpv is good for 17-18 psi, BUT u can mod them to hold >20psi easily and besides that the only better bpv is a jdm sti bpv. bovs are TEH RICE and u may THINK ur turboxs type h held fine but how do u know? did u log to see that it wasnt leaking? because even if it IS LEAKING ur computer will compensate and you will STILL HIT TARGET BOOST BUT UR TURBO WILL HAVE TO WORK MUCH MUCH HARDER TO GET THERE! recirc it theres no way ull win this one ;)

not trying to be a jackass, but i think ive done more reading on this than most people haha...reason being was i wanted one so bad...i had them too (3 of them, 3 different ones damn what a waste) and none were good. i came to realize that its just not meant to be and WHY they are so bad. do what u wnat, but when i beat you dont cry :D haha jk!!!

C-Rex

11-25-2006, 06:37 PM

First, lets get something strait. I don't want a BOV. I know that a recirc is much better performance wise, and besides that BOV's are annoying. I'm not planning to change mine until it's necessary, and even then, i'll go recirc.

You are right that BOV's are no better than stock BPV's but that doesn't make the stocker good. Even if it's a recirc, the stock BPV is the same design as most BOV's. it's a spring piston that's lifted by vacuum when it vents. it just vents to the intake instead of the air. if it leaks, the air will go into the intake, but you will still lose pressure and the turbo will still work harder to reach target boost. if you mod it to handle more, you will still get compressor surge. It's just a flaw in the design.

The SSQV uses the boost pressure to hold the valve closed, so it can't leak. Although I hate the way it sounds.

brent

11-25-2006, 11:55 PM