ImageX

Hey guys, I'm pretty new to Subarus and the many mods you can put on them. I got an '04 WRX and it had a Turbo XS BOV when I bought it. Sometimes when it is warmed up, the idle drops when I put it in neutral at stop signs/stop lights almost to the point where the engine sounds like the rpms are so low that it will stall. I've done some searching around here and found that the BOV could be a part of the problem if not the whole problem. I was wondering if anyone could tell me how I know if my BOV is at least recirculating some air to the engine when it pops. It does have a small tube going from the end of it back to the middle of the inlet manifold below the throttle body. I've also noticed that my BOV is non-adjustable but it does have a rather stiff spring to hold the mechanism forward and not release pressure so I don't see how it could be leaking pressure to cause the idle to drop. If anyone has thoughts on this please pass them on to me or if you think I should get a stock BPV I will do that because I don't need the PPSSSHHHH sound really. I'd rather have my engine running rock solid. Also, if I do get a stock BPV will it pop onto the FMIC pipe where the BOV is right now just before the throttle body? Or does it mount somewhere else and I'll need to plug the spot where the BOV is? I don't know how it mounts because I haven't had one haha. I appreciate any help I get and I guess I'll talk to ya later.

- ImageX

P.S. - Any cheapest method for fixing this is a must. My work is slow right now and I don't have much money. So if I can make this BOV recirc if it is not I will do that for now or if I can get a stock BPV for free/cheap I will do that also.

Dnayukns

iTrader: (5)

Well theres mainly 3 kinds of bov/bpvs. The pure air one, where it just vents to outside the car and u get the loud PSSSHHHHH. The 50/50 one where 50% of the air goes back into the engine(not too sure where) and 50 is the PShh sound. The last one is where air is 100% directed back to the engine and you don't hear anything. BPVs are bypass valve, the air basically goes somewhere else i think lols.

Because of ur BOV, ur air/fuel ratio will be off - making it too lean/rich and that's probably one of the causes of ur issues. That and you should probably get ur car tuned.

Get a stock BPV, you don't need BOV's until ur running like 400+ hp and the pressure gets kinda crazy not to vent it into the atmosphere. I hope that helps, and hopefully someone with more technical info can back me up =D

ImageX

Thanks for the response. As for your recommendation of me getting the car tuned, yes I think it needs to be but no I don't have the $400 to have it dyno-tuned. One thing I've noticed is that the boost doesn't have a controller on it so my boost will go all the way up to 2.0 BAR (29 psi.) if I give it enough throttle. So I think that's what the previous owner put it on for was for when you don't watch the gauge and let the boost get up that high. I think when I put a stock BPV on I need to get a boost controller. If anyone has other tips like I was wondering where the stock BPV mounts to and where it passes the air to that would be great so that I can get this thing running a bit smoother and have more peace of mind. Thanks.

- ImageX

WRX409

1.Bov's are a waste of perfectly good pressurized and cooled intake air.
2.Yes they will cause you to run rich.
3.Yes they can hurt performance.
4.Yes your stock BPV can handle more pressure than factory settings up to 18-20 psi.
5.Most "50/50" valves are just as bad if not worse than traditional Bov's.
You don't need and you shouldn't want a blow off valve unless you are
running a big turbo with big boost.