[cann]

i got a blitz dual drive blow off valve, going to install it later, but i heard from different people
such as
1. it'll lose boost faster
2. it'll spool up faster
3. it'll help performance if tuned correctly, i.e. the nut in the right spot
4. it'll decrease performance since the pressured air will go to atmosphere and some sensor will messed up
5. only better - stock one will leak later one, better sound and lower chances of compressor surge later coz u can hear the sound.

anyone has a aftermarket bov on their WRX that can give me advice

 

[F-L-E-S-H]

I've never owned a BOV, and honestly I'm not too sure about what benefits it brings, but I LOVE the hissing sound it makes. I would be interested in getting one too but only, of course, if it actually improves performance/responsiveness. 8)

 

[CloNeGTS]

Unless you think you are experiencing bad performance with the stock bypass valve, I wouldn't mess with a BOV. Yes, venting to atmosphere is going to mess with your fuel settings big time. With a MAFS type system, the engine is counting on receiving x amount of air, to which it added y amount of fuel. If you go squirting air off into the atmosphere that it is counting on, you'll run very rich whenever you shift, blow off, etc.

If you vent back into the intake tract, that's a different story.....but then I don't know that you'll get any benefits. Doing this doesn't give the giant "Pssssh" people always go putting BOVs on for.

 

[Tb311]

yea people say that all the time. The thing I dont get is that the bypass vavle dumps the air back into the intake tract after the MAF so how does that work? can some one clear this up for me.

 

[CloNeGTS]

Yeah, it's exactly as you said. The engine is expecting X amount of air. As long as you keep that amount of air between the engine and the MAFS, you're fine.

We had a great discussion about this...oh......5 months ago. Not real sure where that post is though.

 

[YBnormal07]

We had a long discussion on this in the STi Powertrain Forum. I believe the thread was titled WRC BOV. Thanks again Rob for all the technical insight.
Scott