bsuby36

After reading many forums about Greddy BOV's, I am a bit confused. Let me get the straight, if I get a 100% atmosphereic, then my BOV will be loud, but the car will run lean, which will cause problems. If I get 100% recirculated, then it will not be noticable and I may as well kept stock in. My question is, have i interpreted this right, and if so where can i get a 50/50? I do not want to spend more than 200 on the BOV. I appreciate any advice or info!!

I was looking at the greddy type rs to buy, any suggestions or feedback??

depdivr

No, thats not correct. So here is a post of mine from another BOV thread that may help explane why the car runs RITCH with a VTA... hope it helps all to understand how a BOV works in our Subys.

Actually, if the BOV is a VTA (vent to atmosphere) - it absolutely should cause the car to back fire. Unless modified, the BOV is positioned after the MAF (mass air flow sensor). As your turbo pressurizes air, it pulls more air through the intake past your MAF, this air travels from your turbo (now pressurized), to your IC, past the BOV and into your intake manifold. More air = more fuel = more power. Fuel calculations are made by your ECU using the input data from your MAF sensor.

Under WOT (wide open throttle) and running with boost, you are pumping a serious amount of air and fuel into the cylinders to give you the power you need. You rev up and shift, at the point that you shift - your BOV vents to atmosphere but you are still drawing a huge amount of air through the MAF, for a split second your ECU gives an proportionate amount of fuel but you just blew off all the air that would have leaned out your mixture to the correct point. End result is a super rich mixture for a split second at shifts. The unburnt fuel travels out of the block into with your exhaust gas, hits the oxygen rich atmosphere (end of the tail pipe) and ignites... tada! Backfire.

Anyway - its not a bad thing. Lots of seriously high performance cars run this way but if you don't like flames shooting out of your ars and big booms as you pass the HWY Patrol, recirculating is helpful. Personally, I have the best photos of my car with a VTA BOV - nothing says power like fire out of your tailpipe. Anyone see the December Issue of Sport Compact Car? The Skyline on the cover... I think it says "BOSS" is demonstrating the photo power of a VTA BOV.

A recirculation type will prevent the ritch condition which occurs with a VTA.

You don't need an aftermarket BOV until you are running 20 or more psi of boost. There are alot of guys around here who do run a aftermarket BOV on their stock cars, some say that it sacrifices drivability - I think it makes them look like a poser. Anyway, a decent aftermarket BOV is going to be $200.00 or more. Spend the cash on suspension, you will get way more out of it than a poser whoosh of air.

rustokman

don't get either... you don't need it... buy something else if the money is burning a hole in your pocket...

XS WRX

once i get the money together ill be buying the Greddy T518Z turbo kit and running 20 psi. is a VTA BOV better than a 50/50 at this point? or can it still have negative effects on the car? (richness) - ill be running 1, 3" high-flow cat with this setup so im not worried about flames, just running rich/lean. thanks for the help.
-Chris

pablo_her

iTrader: (2)

i have a greddy type rs that i took off my car. i only used it for about 1 week and a half. its up for trade of sale if you want it i have the full kit so if you want to run vta or you can add the pipe that comes with it and reciculate it. the only thing missing in this kit is a gasket and a couple of zip ties

Me&05WRX

iTrader: (2)

BOV's are for nothing, but hissing sound at every shift; unless, boosting 20+ psi.

Depdiver hit the spot for explaining as to how it works. Very good explanation... props to you!

DEMENTEDWRX

get one... you know you want to no matter what we say. it works for people... and it doesnt work for people. buy it... if you dont like it, sell it.

Donkey

I suggest the Forge recerculating divertor valve for higher boost.It has a spring kit so you can adjust the tension for your boost pressure.A plus side to a recirculating valve is it will vcause a "pin wheel" effect when it opens and goes back across the compressor wheel which keeps the rpms up on the turbo and by doing so it also keeps the charge pipes/intercooler pressurized as well.If you vent to atmosphere you have to re-pressurize the charge pipes/intewrcooler before you start building positive pressure again in the manifold.This makes more of a difference on big turbo/big fmic cars.
http://www.forgemotorsport.com/conte...duct=FMDVSUB02

XS WRX

it says it keeps external noise to a minimum, but it sounds good in the sound clip - not silent.
-Chris

Donkey

Ya if you run it with the snorkus/silencer removed on the airbox you will hear it even more.Or if you decide to go to an intake or something it will be more noticable.

megaben300

Poser or not, I bought one just for the sound, and the look under the hood. I got a Forge VTA and I love it. It has a nice rally type whoosh sound instead of the chirping whistling sound of most other valves on the market.

As far as running rich, backfiring, and decreased drivability, I haven't experienced any of these. But I also run a straight pipe exhaust (no mufflers or silencers) and have had popping and rumbling backfires between shifts for a while. It's not like ghetto KABOOM everytime I push in the clutch or anything, just random popping when decelerating in gear. Very Rally-esque.

Anyways, if you want one (and you konw you do) then go get one! You spent the money on a turbo car. Nobody can call that rice or poser when there's people with NA cars with fake electronic blowoff valve sounds or flamethrowers in their cars. If your car has the nuts to shoot fireballs and rumble like a rally bred beast, then make it that way!

hulksmash

[QUOTE=Me&05WRX]BOV's are for nothing, but hissing sound at every shift; unless, boosting 20+ psi.

prove it.
my factory bov leaks at 18psi.

sleeze227

I just pulled mine off my car yesterday, and I noticed that the whole system seems to be happier. I don't have much done to the car; intercooler piping, CAI (which also is coming off and back to stock), stock turbo and intercooler. When I took my Forge Atmospheric BOV off it was a little cranky for 5/10 minutes idling, but after that no problem. It's nice to not have people hear your car coming from 1/4 to 1/2 mile (at night).

KronikInsomniaK

iTrader: (1)

i have an hks bov, with helix uppipe/turboback, car idles fine, occasionally backfires but the car runs great.

*edit* i caved in and bought it for the sound, my opinion is if yoru already craving that psssh sound now your gonna end up getting one sooner or later might as well be sooner. as for engine problems from running rich, people's experiences vary and that can partly be attributed to the brand of bov your running. after i got mine i think the problems described are sometimes overrated. just get one used for cheap and if you don't like it sell it at a slight loss. my 2 cents

roadkillSTI

i cant belive people still ask this question
S E A R C H