Bov

mkiii88supra

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Jan 15, 2006
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can someone tell me what the advantages and disadvantages of recirculating your aftermarket BOV? i have an HKS SSQV and im just wondering if i should or need to recirculate it. thanks
 

suprasport91

GO BRUINS!!!
Sep 27, 2005
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the air will get recirculated and accounted for as it is metered air that is escaping..running wihtout it recirculated will cause you to run a little bit richer than before
 

aye mate

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Mar 30, 2005
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Advantages of recirculating are that its quieter and inbetween shifts you won't go super rich which might cause stumbling.
 

Supra5MGTE

New Member
Nov 11, 2005
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Tampa, FL
I'm getting a recirculating type BOV for our car. I think i'm going with the H-34 turbo XS. think it's basically just a recirculating RFL from what i've seen of it.
 

Supra5MGTE

New Member
Nov 11, 2005
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don't think so. my buddy had a GST Eclipse and he ran a RFL and a AFC and it always stumbled after blowing off and not getting back on it. AFC alters the MAF/AFM if i'm not mistaken. only fix is run a MAP sensor set up, or just recirculate it.
 

solid400

New Member
Apr 8, 2005
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Atlanta GA
i really wouldn't worry about it, i've run open atmopshere off my HKS for a couple of years, the worst thing i get is the occasional backfire. And this usually results if i'm slow between shifts, if i'm quick it doesn't seem to do it.
 

robeats91t

237lbs. of Ballast
Jun 4, 2005
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Tampa, FL
After blowing the diaphragms on two different bosch recirculating valves, I upgraded to a blitz bov vented to atmosphere. Even after proper adjustment, it seems like there has been a slightly noticeable decrease in boost response between shifts.

Forgive my memory, someone here on this forum has a great quote in their profile, goes like--"power makes noise; noise does not make power"--and in this case I feel like that statement rings true. That cool "pssh" sound costs power. It's pressurized air escaping from the intake tract. Of course, you could look at it as a way of ensuring the turbo is better protected against compressor surge, given that the bov is properly adjusted. But to put a vented bov on a 7M with a stock ct-26 near stock boost levels for the sole purpose of added protection would seem to be overkill.

Also, as others have said, the way the stock air metering is set up on our cars can cause stumbling between shifts if you're driving easily. After I installed my Blitz, I seemed to stall it at the most inopportune times. Rush hour traffic especially sucked, but maybe it was just me. Eventually I adapted, and now I don't even think about it.

Based on my experience with my Blitz, I have two things to say:

I love how reliable it is--it's so quick to relieve pressure, even in it's stiffest setting. After killing my stocker and two bosch valves, I am pleased with the sturdiness and simplicity of this valve

I plan on making a recirculation adapter for it. Now that the novelty of the "pssh" has waned, I want to try reintroducing that "blown-off" air into the intake and see if I gain any boost response back.
 

jester1341

topless and blown
Mar 30, 2005
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i run a Greddy Type-S and get a backfire every now and again, more often since i did the 12V mod

when i "get on it" it never has time to 'stumble' :evil:

john

P.S. that Psssss-hooo is so intimidating tho if you ask me, other than that i agree recirculating it the hands down best way to do it
 

rakkasan

Currahee!!
Mar 31, 2005
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mkiii88supra said:
yeah but wouldnt tuning it with an S-AFC get rid of that richness?

Yes it's used to adjust your fuel, but you can't compensate for venting to atmosphere with a SAFC. When you vent to atmosphere, you're losing air that the ECU thinks is there, so your ECU is still going to add the fuel for the air that was lost.
 

diy guy

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Jan 25, 2006
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^ yeah you can, only not for karman type meters that use frequency vs voltage output.

maf sensors also meter air before the turbo but the rich stumble can be corrected via safc by telling it to clamp the maf output voltage to a non rich condition when "x" -deltaThrottle is applied.

map sensors eliminate the problem altogeher.
 

mkiii88supra

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Jan 15, 2006
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but im going to be running the upgraded AFM so i didnt know if that would change it. if i feel i do need to recirculate it, how would i do that with a HKS SSQV?
 

jkbmkiii

Supramania Contributor
Nov 24, 2005
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Castle Rock colorado
you can get A fitting for the hks ssqv so you can re-cir/ I dont re-cir ( PNTA)
on top of I can deal with the backfire thing every now and again!!!!!!
 

tubbie

Yes, powerful Jedi....
Apr 4, 2005
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rakkasan said:
Yes it's used to adjust your fuel, but you can't compensate for venting to atmosphere with a SAFC. When you vent to atmosphere, you're losing air that the ECU thinks is there, so your ECU is still going to add the fuel for the air that was lost.

Or... you can use the HKS SAFR and it has compensation for the bov venting. Great little tunning gadget. Just too darn ugly. :biglaugh:
 

rakkasan

Currahee!!
Mar 31, 2005
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diy guy said:
^ yeah you can, only not for karman type meters that use frequency vs voltage output.

maf sensors also meter air before the turbo but the rich stumble can be corrected via safc by telling it to clamp the maf output voltage to a non rich condition when "x" -deltaThrottle is applied.

map sensors eliminate the problem altogeher.


Sorry, but unless you have another device that meters how much air is released by the BOV (like a SAFR as Tubbie pointed out), the safc can not compensate. I think you're confusing draw thru vs blow thru maf.