A lot of members here, and myself (have), use one way check valves on the end of the bov to keep it closed on idle. This is the same premise, but designed for a bov, not water.

Is it necessary to use something like that to prevent leaking at idle with any bov or does the Bosch unit not have any leaking problems?
-Ryan

The Bosch unit leaks at idle, but, because it recirculates, it's not a matter of any concern.

My Turbo XS Type S doesn't leak at idle

Not a matter of any concern as in, because it recirculates it doesn't cause idle problems? Does the leaking cause any performance losses? It seems like if its leaking it can't be good...

-Ryan

Not a cause for concern because it recirculates, so, yes, no idle problems. When you're under boost, it's held shut by the pressure on the signal line. While you're idling or in partial vacuum or light boost, it can leak a little bit, which is fine. That's what it's meant to do.

Edit for spelling.

This has to be the longest thread about BOV ever... thats even comapring it to M.net. You girly men!

I think I'll add more riviting multimedia to the discussion. I made two quick videos of my recirculating bov as heard while driving with the top up.

http://www.rev2red.com/images/cars/CIMG0108.AVI

http://www.rev2red.com/images/cars/CIMG0109.AVI

Sounds about as loud as my VTA with filter, not very loud at all, just enough to hear if you're listening.

It's noticeable but not as apparently loud like some other bov's. It cant be heard from the street as well as other cars on the road. But it is significantly quieter than when I ran it vta.

Im hoping roman posts what his FM, VTA sounds like.. Its loud..

When recirculating, the Bosch doesn't leak, it is held open by Vac, allowing the air to recirculate. and as Brian has mentioned absence of Vac closes it.

One of my Subaru owning neighbors has one of those short ram air filter systems on his WRX STi. It's pretty loud, I heard him coming down the street with it. My BOV is VTA, but it has a dust filter around it, it just whispers when it lets off.

Try running a bigger vacuum line to it.

My recirculating bypass is cast into the compressor housing, and it's fairly loud when just driving around town at part throttle. Between shifts, though, it's about like Braineack's.

ThePass

If you read the text a little closer on the link that you supplied you will see that it says
"The piston is actually fitted with a piston ring for a perfect seal. Combined with a well-chosen spring, this means the valve can be used on a car that uses a MAF or AFM to measure airflow."
The most important part of that statement is "with a well chosen spring", a perfect seal can be detrimental in a VTA BOV on a MAF car if the spring rate isn't correct. There are piston type valves on the market that work because the tollerances are so loose that the vacuum will not lift the piston at idle. If the valve is designed with an airtight seal, such as ours and the GFB that you listed, the spring tension needs to be chosen for the application. That being said, I never recommend a VTA valve on a MAF car. Which leads me to the following...

firedog25

Do you know the color of the spring in your valve? I can send you the next stiffer spring to see if that cures the problem. Or we can go another route and get you the right valve for your application. If you prefer to have VTA you would need to use our 004:
http://www.forgemotorsport.com/conte...roduct=FMDV004
Or if you wish to recirculate go with the 007:
http://www.forgemotorsport.com/conte...oduct=FMCL007P
Just ship us the 003 and I will send you your choice of these two valves with no additional charge.

Pat

When they say it can be used with a MAF/AFM car because of the well-chosen spring and seal, they just mean it won't leak at idle. If it's a vent-to-atmosphere, it'll always run rich between shifts in addition to possibly leaking at idle, unless that well chosen spring happens to be on so stiff it renders the piston useless...at which point you no longer have a functioning bypass valve :)

Well I figured I might as well contribute my experience w/ VTA and recircs as well as the BOV of choice for me.

First of all let me say I ran a eclipse GSX @ 17 psi running several different BOVs. First I had a turbo XS RFL (really ...loud). I blew off about 5 feet from some lady and she banged her head on her roof cause it made her jump (she was bent over gettin something out of the seat). As great as that moment of my life was, the rest sucked. My car ran rich and dumped fuel between shifts and also had a very crappy idle due to the MAF trying to compensate for the air.

Next I tried the 1g DSM metal BOV. Let me tell you, if your looking for a SOLID (17-20psi uncrushed) bov.. this is it. Its SUPER quiet and you can get it ALREADY flanged onto the 1g DSM pipe section for roughly 40 shipped off dsmtuners. com.

I however, upgraded my pipes and transitioned to the Greddy Type-S (no longer made I guess). This BOV held boost awesome and possessed I would describe as a "middle" loudness sound. It sounded like a "Ka-Chink" between shifts. I ran it at 14 PSI and it held fast. If I could find one again I DEFINITELY will use this on my turbo miata.

Hope this helps w/ your selection.

It's what I'm using suckers.

Really? COOL. Could you e-mail me information about this at firedog25@iafflocalf-53.org? Thank you.