bov question

so my co-worker purchased a 2005 WRX 5spd a few weeks ago. he already has an spt catback and spt short ram installed and he really wants a bov. i have heard two sides to the argument. one is that it could harm the turbo and the other is that it will neither help/hurt your car. so which is correct? he is pretty stubborn though and will probably buy it anyway but i figured i could try to save him the hassle/stress.

depends. If it's open atmosphere (most likely is) then he may run into problems stalling when coming down to idle. The air escaping the BOV is already compensated for via the MAF sensor, so the car runs slightly richer than normal since the ECU thinks X amount of air is going into the engine, when it's really going to the atmosphere for the sound.

I've heard ok things about the GFB blow off valve (the ones that some suby dealers sell), it's a 50/50 split. 50% of the air is recirvulated, and the other 50 gets vented. You get the noise and you also dont have to deal w/ stalling and other issues runnning rich off the gas.

As far as harming the turbo...that's a first for me lol. I'm sure someone installed a BOV and then did something stupid to hurt the turboa nd blamed the BOV for it instead of their own stupidity lol. I dunno.

It shouldn't hurt the turbo but if you go atmospheric you will have to have the engine remapped to accomodate it.

In truth, the bov Subaru have is more than sufficient for the boost levels the turbo generates, the only reason people want to replace them is to get a louder (read: atmospheric) one.

Comes down to this: unless you're getting an engine remap, there is no benefit to changing the bov.

thank you guys. i printed out this page with your responses but he still seems dead set on a BOV, haha. He was mentioning he liked the sound of the HKS and Forge bov are those atmospheric?

thank you guys. i printed out this page with your responses but he still seems dead set on a BOV, haha. He was mentioning he liked the sound of the HKS and Forge bov are those atmospheric?

I've never heard a forge bov. I've always used the HKS Super Sequential. It sounds like an Eagle on crack.

I've never heard a forge bov. I've always used the HKS Super Sequential. It sounds like an Eagle on crack.

i hadnt heard of forge either but i googled it :) they do exist