ROTORHP

Does the stock BOV always bypass air at idle? Mine quits of course as soon as you blip the gas, dropping the vacuum to the BOV but why it bypasses at idle strikes my curiosity. ???

twinturborx7pete

iTrader: (3)

yeah, most stock bov's blow air at idle... its just a weak valve unlike an aftermarket spring valve. I take it you have them vented.. its nothing to worry about. But you just might want to get an aftermarket one if it bothers you.

duboisr

ON a stock 3rd gen only one is a bov the other is venting the prespool air from the second turbo .

ROTORHP

Ya the BOV is the one I'm talking about.... I am planning on venting it so I popped it out of the box when it was running and found it was bypassing. So not a big deal then huh? And stick a filter on it as well? Some do and some don't.... Do I need to filter the BOV?

duboisr

A filter may stop some oil from blowing all over the place, the turbo will pass some oil into the air stream.

Mahjik

iTrader: (1)

You might want to take a look at this thread:

https://www.rx7club.com/forum/showth...hreadid=136125

ROTORHP

Read that thread Mahjik. The BOV seems to vent outward, not sucking in. It constantly blows air out, back into the airbox. When I rev up the engine, the vacuum drops, slaps the BOV shut from what i felt, until it overboosts( like you didn't know) then it goes POOF and continues to leak right until and while it idles. That is why it is bugging me... I didn't think it should keep leaking...

Snook

iTrader: (12)

when I blew an apex seal my bov was letting out so much air at idle that it was like another exhaust

Normally while idling though my bov never lets out any air

Your valve may be releasing at a lower pressure than it should

how much boost are you building with it?

venting it is no big deal at all just do it

Mahjik

iTrader: (1)

No problem. After reading that thread (and others about the stock BOV), I wouldn't vent it without a filter. However I installed the Apexi instead of messing with it.

ROTORHP

My engine runs soo smooth it couldn't be a apex seal. I don't know what boost I have....no gauge yet. Getting one however but need clutch first. Your BOV doesn't leak at idle Snook? Hmm I think I will stick a filter on it(K&N PCV filter) until I can get a pipe kit and a aftermarket BOV.

Snook

iTrader: (12)

Mahjik isn't that other thread so much BS though? Lots of other people have argued the other way about this and were 100% possitive that the bov is just a one way valve and I agree. The BOVs draw in air when at vacuum? Go outside while your car is at idle and plug up the bov with your hand. Nothing should be happening at all. I'm pretty sure this was the same when I was running sequential and I'm positive with non sequential. I think the only reason for a filter would be so nothing gets into the bov while your car is turned off such as bugs pretty much. The point of venting the bov was to get it louder I thought...by adding a filter it will be quieter than when it went through the air box so don't even vent it if you do that.


ROTORHP if you cracked or totally threw out an apex seal you would know it. Cracking one is a little harder to detect but you will have very little power down low. Like if your idle is 750 and you go to drive off from a stop light it will be very hard without stalling. Once you get to about 1100 rpms it's fine though and it revs just like a new motor througout the rest of the rpm range.

Mahjik

iTrader: (1)

I don't see how venting it into a small filter would be quieter than venting it into the air box with a larger filter. The BOV is still on the filter side when it's attached to the air box, so it's a similar principle, just with the air going through a filter and into the open instead of ultimately into the air box. So I don't see how that would be quieter.

Apparently Tri-Point gave a similar response. I trust the pros a little more than what I "think" it should be doing.

IMO, I wouldn't risk it for such a small pay off (just a louder sound), and I didn't. I'm using the Apexi if you didn't see my sig above.

I'm not saying you should or shouldn't vent it with or without a filter. I'm providing other opinions to let people make their own informed decision.

ROTORHP

My car has no engine problem. It has fine power and response low in the rpm with no stalling. Mahjik, I agree that a filter shouldn't make a difference changing the sound either. I still would like to know if other peoples BOV does the same as mine......