Stupid question time about BOV and BPV

[lewisb01]

What's the difference between the two?

It seems the forge BPV is the choice on these boards, I guess I'm trying to get a better understanding of the two. THanks in advance.

[ericrapp]

I am sure there are many who will speak up. I am new to boost, so this is opinion at best. A blow off valve allows boost to vent to the atmosphere when you get out of the throttle after boost is generated. The diverting valve, takes the excess pressure that the valve controls and when released recirculates it within the system. This affects sensors reading. I have read that our cars on the stock ECU need to recirculate that air. I use a forge valve with 100% recirc. Because I have not tuned the car yet. This is just opinion though

[jlocurto]

i am new to turbos as well
but from what i understand is that our cars run really rich already.. and when you have a BOV it makes the engine run even more rich. running a BPV recircs the air back into the intake to keep everything they way that it should be
i personally have the forge BPV and i like it...

also bov are really loud if you want that.. but the forge bpv does make some noise even with the stock intake. i hear that it is a lot louder with an aftermarket one

[ericrapp]

One of the reasons Forge is popular on the forum, is that Patty at Forge has been very accessible for all kinds of questions and answered them. As many vendors have been. Customer interface with a quality product makes an impression.

[UHATEIT]

here is a link to my thread with pics and videos of a bov/bpv and the different sounds when venting (BOV) and recirculating (BPV).

http://www.mazdas247.com/forum/showthread.php?t=123711199

MOST inits have a neck that sticks out, like the stock valve has the part that stocks into a black hose (recirculation). But you can unplug that hose and let the valve vent into the ait and thats what causes problems with the car but you get a nice loud sound.

BOV is when you let it vent out, BPV is when it is recirculated by plugging that tube onto the end of the valve so no air is lost.

But you can buy valves like the greddy, forge, turbo xs, hks, synapse, pretty much any of those and let them vent, or just plus the valve opening by putting that tueb back on it. Just look for the ones that have that piece sticking out on the side so that you have something to plug into, that way you can vent or recirculate at your own decision, here is a pic too of the bov so you can see the sticking out edge that can be elft alone of recirculated:
http://memimage.cardomain.com/member_images/3/web/3087000-3087999/3087711_23.jpg