Bov Faq
- Thread starter AAMguy
- Start date
I have one question that didnt look to be covered. I will be ordering the Forge soon, I have heard that the blue spring is the best for our application. But I have also heard of "shims" to further adjust the BPV. Can sombody explain this, what do shims do and how many do you all run in the Forge? -Thanks
oh, alright, idk too much about them so i'm not sure. like in most applications for other cars it won't make a difference?
thank you for making this tread
screw the forge its not as good as the HKS SSQV and it sounds like some elf snezing.
save up another 70 bux or so and get a HKS SSQV
this thread is not about sound...
and do not say screw the forge considering I have tuned high horsepower cars using their valves. If i was going to setup a vta car then I would choose a hks because of the no stall design, but the forge is a great bpv.
BrianFiebig
Member
- :
- 08 SPEED 3
Question about the HKS SSBOV. Im looking in the protege garage store, and there is a recirculation adapter thingy. Does this mean that I can actually run the HKS SSQ in a recirculation mode, getting the sound and not worrying about compressor stall etc? Or should I just stick to the Forge Unit in my shopping cart?
john blutarski
Member
- :
- 2004 Subaru WRX STI
Yes, you can buy that recirc adapter for the HKS and run it in full recirc mode... but for half the price you can get the Forge which performs just as good.
RPM problem with HKS in VTA or Recirc
"the only way most people will be able to tell a difference would be to go and by a blow off valve, run it on the car show off to all your friends. then put back on the bypass valve or run the valve you bought in recirc and you will be able to feel a huge difference, and the car will thank you for it."
This is exactly what I've done. I put the HKS with the CP-E kit on my car in VTA. Immediately I noticed that the RPMs ran different and the car drove like crap, rich, and bogged inbetween shifting.
So, I went back in and made it recirculate. The car runs great but there is still a weird RPM discrepancy that makes me feel like something still isn't right.
My car idles higher than it used to, and when driving the RPMs don't match up to the speeds they used to, i.e. in 3rd at 3k RPMs would be about 40 MPH, now it takes 3.5k to get the same speed.
Anyone know what the cause of this might be? Loose tubes? Computer adjusting? The vaccuum filter that wasn't there before? Would the stock BOV fix it probably?
I appreciate your help.
"the only way most people will be able to tell a difference would be to go and by a blow off valve, run it on the car show off to all your friends. then put back on the bypass valve or run the valve you bought in recirc and you will be able to feel a huge difference, and the car will thank you for it."
This is exactly what I've done. I put the HKS with the CP-E kit on my car in VTA. Immediately I noticed that the RPMs ran different and the car drove like crap, rich, and bogged inbetween shifting.
So, I went back in and made it recirculate. The car runs great but there is still a weird RPM discrepancy that makes me feel like something still isn't right.
My car idles higher than it used to, and when driving the RPMs don't match up to the speeds they used to, i.e. in 3rd at 3k RPMs would be about 40 MPH, now it takes 3.5k to get the same speed.
Anyone know what the cause of this might be? Loose tubes? Computer adjusting? The vaccuum filter that wasn't there before? Would the stock BOV fix it probably?
I appreciate your help.
I was about to say that this happens to me when swapping from vta to recirc and back. I believe the computer needs to get used to it. Probably will need 10 key cycles or so for it to cattch back up to being recirc.
I had mine VTA and had no CEL, but then when I put it back to recirc the CEL came on, but then went away after I drove it around for about 30-50 miles or so, so i think it needed time to refresh. And the car did run weird at first being back to recirc. It went back to normal after that 30-50 mile stretch. Try key cycles or go drive it around for a while and ti should refresh the system/ecu
ZoomZoomPSSH
Member
Been reading left and right concerning the VTA vs Recir debate. I'm pushing to go towards investing in a Forge BPV but I also stumble across the Street Unit Performance Black Out Edition Compact Dual Port Blow Off Valve Kit by TurboSmart.
It VTA AND RECIRC under high boost conditions. I wanted to get opinions from knowledgable members concerning this Turbosmart valve. (I.E. Does it offer any significant benefits over the forge, etc)
Thanks
It VTA AND RECIRC under high boost conditions. I wanted to get opinions from knowledgable members concerning this Turbosmart valve. (I.E. Does it offer any significant benefits over the forge, etc)
Thanks
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a 50/50 hybrid is fine. some guys here are running VTA but the car isnt as efficient. doesnt run nearly as smooth as recirc.
but a 50/50 is totally fine.
why are you wanting to run VTA? there is no benefit to running VTA. it actaully hurts the performance of the car.
it would be understable for sound if you had something like a Greddy Type S which is one of the best sounding bov's, the HKS SSQV is another running in VTA but this is a MAF car and is made to run in recirc.
i have the Greddy Type. ran in VTA for like 10 mins. loved the sound, hated the way my can ran and hated the smell so i put it back in recirc mode
with a SB i believe there is a tune to allow the car to run properly in VTA
but a 50/50 is totally fine.
why are you wanting to run VTA? there is no benefit to running VTA. it actaully hurts the performance of the car.
it would be understable for sound if you had something like a Greddy Type S which is one of the best sounding bov's, the HKS SSQV is another running in VTA but this is a MAF car and is made to run in recirc.
i have the Greddy Type. ran in VTA for like 10 mins. loved the sound, hated the way my can ran and hated the smell so i put it back in recirc mode
with a SB i believe there is a tune to allow the car to run properly in VTA
john blutarski
Member
- :
- 2004 Subaru WRX STI
I went from a Forge BPV to a Turbosmart 50/50. There was no benefit for me other than a different sound. Performance is the same for me.
ZoomZoomPSSH
Member
I don't want to run VTA...just wanted to know if it was better to run a combination of both at high boost rather than simple Recirc.
Thanks for the help.
mazdasp33d
Member
- :
- Mazdaspeed 3
i have no idea what bov/bpv to get. its drying me nuts. forge has been shown i guess that it is one of the best for our cars. but i dont like the sound
Wait, what's wrong with the greddy type-s? I ran mine in recirc mode on my DSM for years with no problems. It held boost a bit longer than the stock diverter valve, and sounded nicer. It's probably going to go on my speed3 now that my dsm is being parted out.
If it's installed to recirc.... I don't see a problem with ANY brand of bov. Just about all of them have a recirc adapter available.
Also wanted to add..
There's no good way to tune around VTA. Depending on boost pressure, rpm, air density, brand of BOV, BOV setting...etc... every time the BOV opens a different amount of metered air will leak out. You can make a map to predict how much fairly close, but it would have to be unique to your exact setup, and even then it wouldn't be as accurate as just running recirculated.
The only CORRECT way to run VTA is to move the MAF sensor to the cold side IC pipe, downstream of the BOV flange. Then whatever air the BOV puffs out wasn't metered in the first place, so it doesn't matter that it's gone. You would have to retune your MAF correlation map with an AP (or something) to do this though, you can't just move the maf and run a stock tune. The only other hitch is, the MAF should have at least 6 inches of straight pipe before and after it, must be at least 6 inches away from the throttle body or BOV flange to eliminate excessive turbulence or uneven cross sectional flow (most existing short ram and cold air intakes don't even properly address this). The stock TMIC won't allow that, but it'd be easy with a FMIC.
You could also convert the car to run off only a MAP sensor (speed density), but I'm not sure if this is possible on ours. Speed density systems don't mind VTA, they calculate airflow, they don't directly measure it.
OR... you could just recirculate it.
If it's installed to recirc.... I don't see a problem with ANY brand of bov. Just about all of them have a recirc adapter available.
Also wanted to add..
There's no good way to tune around VTA. Depending on boost pressure, rpm, air density, brand of BOV, BOV setting...etc... every time the BOV opens a different amount of metered air will leak out. You can make a map to predict how much fairly close, but it would have to be unique to your exact setup, and even then it wouldn't be as accurate as just running recirculated.
The only CORRECT way to run VTA is to move the MAF sensor to the cold side IC pipe, downstream of the BOV flange. Then whatever air the BOV puffs out wasn't metered in the first place, so it doesn't matter that it's gone. You would have to retune your MAF correlation map with an AP (or something) to do this though, you can't just move the maf and run a stock tune. The only other hitch is, the MAF should have at least 6 inches of straight pipe before and after it, must be at least 6 inches away from the throttle body or BOV flange to eliminate excessive turbulence or uneven cross sectional flow (most existing short ram and cold air intakes don't even properly address this). The stock TMIC won't allow that, but it'd be easy with a FMIC.
You could also convert the car to run off only a MAP sensor (speed density), but I'm not sure if this is possible on ours. Speed density systems don't mind VTA, they calculate airflow, they don't directly measure it.
OR... you could just recirculate it.
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I have a question! Is it possible that a BPV can adjust itself with vibrations from driving and heat and whatnot? Because on my ex gf's speed we had her Turbo Smart adjusted perfectly right before we got it tuned and after the tune it was at the same position. Well a few months later I look at it and its tightened all the way down so I had to loosen it back up as the car seemed to be running different and thats what made me look under the hood... What gives? Could someone have done this while the hood was popped? I can only think of one person who could have MAYBE tried to sabotoge her 3? Usually when we had the hood popped at an event or meet we never left the car unattended and I honestly dont think that person would have done something to it as usually it takes some time to even get my hand in place to adjust it and we would have caught them lol. We were both pretty anal about the car lol. Anyway this was a while back and I am concerned for future reference. Anyone experience this?
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ZoomZoomPSSH
Member
that's strange. I wouldn't really know. Maybe someone messed around with it while you weren't looking. I just went with the HKS valve so I wouldn't have to adjust it or worry about things like this happening.
