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Old 07-27-2003, 11:58 PM   #1
gooter80
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Default twin BOV question for the masters

ok so i was at a show this weekend and there was a WRX there with a front mount, turbo upgrade etc etc. i noticed he had 2 bov's connected. one just after the turbo and one right before the intake manifold. what would this actually do? benifits? downfalls? louder? just curious is all.
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Old 07-28-2003, 12:05 AM   #2
mlambert
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Most likely it was just for bling.
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Old 07-28-2003, 12:23 AM   #3
gooter80
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Quote:
Originally posted by mlambert
Most likely it was just for bling.
that is quite possible but what actual effect would it have on performance either negative or positive?
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Old 07-28-2003, 02:03 AM   #4
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After the turbo? How could that be a BOV? Are you sure it wasn't a fancy waste gate or something?

Paul
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Old 07-28-2003, 02:14 AM   #5
mr2guru
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I would assume it was after the compressor discharge and one before the throttle body.

Maybe HE thought that all the piping of the FMIC would take too long to depressurize after throttle lift with only one BOV???

Mabye they open at different speeds and give some kind of cool pshhh.. pshhh sound?

Hell I don't know...sounds like a waste of money to me
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Old 07-28-2003, 02:17 AM   #6
Stoychkoff
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two bov prevent boost creep. if you don't know what boost creep is then here it is:
Normal boost rise when set to 13 psi = shoots up to 14, then 13, 13, 13...
Boost creep = shoots up to 14, then 13, 13, 14, 15, 16, 17...
if you want your engine to blow up then you stick with one bov or none... but if you want your engine to survive the boost world then you have to regulate your psi... and one way is with two bov's... it just lets out more psi so you can stay steedy at what ever you have it set at
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Old 07-28-2003, 02:24 AM   #7
mr2guru
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Quote:
Originally posted by Stoychkoff
two bov prevent boost creep. if you don't know what boost creep is then here it is:
Normal boost rise when set to 13 psi = shoots up to 14, then 13, 13, 13...
Boost creep = shoots up to 14, then 13, 13, 14, 15, 16, 17...
if you want your engine to blow up then you stick with one bov or none... but if you want your engine to survive the boost world then you have to regulate your psi... and one way is with two bov's... it just lets out more psi so you can stay steedy at what ever you have it set at

Lay off the crack bro...BOVs have nothing to do with boost creep.....

Wastgates regulate boost. Only one is required...either internal or external. Usually external ones provide better boost control and curb the dreaded "boost creep"
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Old 07-28-2003, 02:26 AM   #8
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A BOV does not controll boost. It helps prevent the turbo from slowing down when you lift off the throttle under boost. You are thinking of a waste gate. I have seen 2 BOV on cars, but they were running insane amounts off boost and had to vent large volumes of air to prevent compressor surge.
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Old 07-28-2003, 01:36 PM   #9
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are you even sure the second one is a BOV? if it was after the turbo, maybe it was made to bypass the cats and muffler. they make dump gates now for our exhausts.

jason
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Old 07-28-2003, 02:34 PM   #10
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Quote:
Originally posted by Stoychkoff
two bov prevent boost creep. if you don't know what boost creep is then here it is:
Ahhh....


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Old 07-28-2003, 06:35 PM   #11
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The more you can vent the less backpressure on the turbo when the throttle body closes.

Not all BOV's are equal, HKS has to be one of the more restrictive ones I have seen & can cause compressor surge on larger turbo/FMIC systems.

Dual BOV's wouldn't hurt if placed properly...

Perfect BOV would probibly be the size of the piping it is venting...

my 0.02
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Old 07-28-2003, 11:01 PM   #12
Dick Fitzwell
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Quote:
Originally posted by mlambert
Most likely it was just for bling.
i second that, probably just for looks.

who's car was it...do you know? from here?
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Old 07-28-2003, 11:25 PM   #13
gooter80
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not too sure whos it was. it just got me thinking because i have an HKS on my car now but i also have a GFB sitting in my room. thought perhaps it would be cool to have both sounds and if it would help with venting. just a thought that crossed my mind. although im sure you all will think its a ghey idea
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Old 07-29-2003, 01:50 AM   #14
Scoobie Steve
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Quote:
two bov prevent boost creep. if you don't know what boost creep is then here it is:
Quote:
are you even sure the second one is a BOV? if it was after the turbo, maybe it was made to bypass the cats and muffler. they make dump gates now for our exhausts.
Ohhh Boy Maybe we should go over what a BOV is.
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Old 07-29-2003, 06:06 AM   #15
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Like GLWagon said.. dual BOVs can help for quicker response.. venting the air out faster than a single.. I've heard the HKS SSQV wasn't the quickest venting bov out there and have seen many people use dual HKS SSQVs to fix that problem.. Other than that, it's purely aesthetic..

Jay
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