BOV vent 100% or recirculate ? HELP

**SOUTHPAW** · 11-28-2003 05:55 PM

I have had my TurboXS RFL on for the past 10,000 miles (since 5k) and I still like the sound. I do think its a little too loud though... Anyway, I have always noticed a ever-so-slight decrease in performance, like others, running rich, stumbling, shuddering at low rpm's.... I wish I could have the sound w/o all the bull$h!t but what am I gonna do? I wanna take it off but I'm so used to having it on for so long! It's kinda like removing that 15 pound tumor you've had on your face your whole life.....no wait, not really....

**YBNormal07** · 11-28-2003 06:17 PM

I've got a fully adjustable, spring perch worxtuning recirculating BOV which is absolutely gorgeous (wrinkle red or blue finish with polished aluminum/ss.). Never had a problem with it, no stuttering, rough idle, etc. Great thing about it is I can adjust it easily so reduce the noise by recircing more air back to the compressor.

It's distinct in sound, but not "look at me" loud. To me, it's the perfect balance between announcing to those that know...yep, it's a turbo" and to those that don't you won't be startling old ladies into dropping their shopping bags.

Check em out. I highly recommend their service!!!
www.worxtuning.com

**2003WRX** · 11-29-2003 12:28 AM

I am running a Worx BOV as well, its been great! They are in development of a new adjustment ring that will make it louder. This particular BOV is awesome because you just turn the adjustment ring and you can go from 100% recirc to various levels of sound/vent.

I tried the HKS once and it made my car run like crap. You'll find peoples experience with the HKS varies quite a bit. My car felt like I was towing about 500lbs after shifting gears... definite and noticable performance degradation. The guy I sold it to reported his car ran fine with the thing....

**kit99bar** · 11-29-2003 12:48 AM

HKS here zero problems at all

**veteq** · 11-29-2003 06:42 AM

Thank you for all the feedback.
Warranty is not a problem. Subaru will install it for me (this way ensuring the warranty remains). The wife wants the sound. My only concern was with loss of power...from what I read here, it's hit and miss. Making my decision that much more difficult.

Veteq

**Silverbane** · 11-30-2003 10:44 AM

Typically the "Hit and miss" nature of an aftermarket BOV is due to the factory MAF sensor.

On cars that use these sensors they are placed before the turbo, but the BOV vents into the intake after the sensor, so to make it easy to understand: If you have 10cfm of air going in, your MAF reads that and adds fuel for 10cfm, car works like normal, any air trapped before the TB when you shift is "recirculated" back into the intake stream and your stock car runs nice and fine

If you have an Aftermarket BOV, you suck in 10cfm of air like normal, when you shift 5cfm gets dumped to the atmosphere (that makes the psss sound) but your engine has already added fuel for 10cfm... so your running super rich, that is what causes the stutter stumble effects, especially while shifting. Aftermarker recirculating valves dont typically have this problem since they function like stock.

Ways around it, stand alone EMS, or things like an HKS VPC (Vein pressure converter) that measure air differently and later in the intake stream, instead of a "flapper" door style that measure air before the turbo(I believe that is what you have on your cars.) These measuring tools typically measure later in the intake stream (closer to the TB) and so it doesnt matter if you dump all but 1 cfm of air since it will only read 1cfm is going in the engine,

FYI the HKS BOV is a very good BOV especially if you vent it back into your intake stream since the pressure holds the BOV closed instead of pressing against a spring like most standard BOV's that, if you have a weak spring, can cause leaking... and since its operated by a vaccum it opens and closes VERY fast, which is why it typically does not cause a reaction as extreme as other aftermarket spring type BOV's when shifting since you dont run as rich for as long.

**20wrx02** · 11-30-2003 02:29 PM

hello peeps .. heres a dumb question you probably heard over and over.

i have a turbo xs BOV that vents 100% to the atmosphere.

im getting a greddy type s that can either vent 100% or the option of me attaching it so it circulates back into the intake.

what should i do ? vent 100% or recirculate.

whats the major difference besides noise ? ?

engine mods ..

injen intake
colder sparkplugs
borla headers
hks uppipe
hks downpipe
blitz exhaust
apexi avcr @15.5psi
turbo xs tmic
turbo xs unichip
turbo xs bov
CO2 intercooler chiller

**BoostedBoxer** · 11-30-2003 02:33 PM

If the bov isnt on recirculate, you will be running a little rich between shifts because the computer is expecting the recirculated air (that the 100% atmosphere bov vents to the atmosphere) back into the intake stream. You wont feel any difference in performance (i didn't between the 2 modes) or see it in gas milege.