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Old 05-01-2012, 06:57 PM   #476
vf22Bugeye11
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Quote:
Originally Posted by calical6905 View Post
A blow-off valve bleeds off the excess pressure in the intake system. Since this pressure is what causes the turbocharger to stop spinning when the accelerator pedal is released, using a blow-off valve means that the power to the engine does not cease immediately once the accelerator is released, allowing for speed to increase even during gear changes. Also, because the turbocharger does not slow dramatically, there is less lag once the accelerator is depressed again, meaning that the power comes back up more quickly after a shift change or deceleration.
Have you even read the beginning of this thread..you are releasing metered air that has already been accounted for, there is a reason car manufacturers do not use ricer ass VTA Bov's on their turbo charged cars.
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Old 05-01-2012, 08:01 PM   #477
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Never will I put one on my car..never.
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Old 05-01-2012, 08:56 PM   #478
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Well it works pretty well on my car. Hate all you want
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Old 05-01-2012, 09:52 PM   #479
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Quote:
Originally Posted by calical6905
Well it works pretty well on my car. Hate all you want
Amen!
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Old 05-01-2012, 09:58 PM   #480
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Well it works pretty well on my car. Hate all you want
Oh im sure it does go phsssss super loud so its at tip top working order hahaha
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Old 05-02-2012, 08:59 AM   #481
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Originally Posted by vf22Bugeye11 View Post
Have you even read the beginning of this thread..you are releasing metered air that has already been accounted for, there is a reason car manufacturers do not use ricer ass VTA Bov's on their turbo charged cars.
have you read the beginning of this thread...the whole purpose of this thread is basically to tell people like you that the 0.5 seconds between shifts that you go rich from having a bov isn't going to hurt anything...AND...as long as the valve is installed, adjusted, and working properly, you aren't going to hurt anything.


btw...the reason factory cars haven't ever used a bov is mostly due to emissions. i bet the evap systems, tgv systems, or the air pump systems are for performance too huh ...guess we probably shouldn't delete those since there clearly is a reason that the manufacturers put them on there.
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Old 05-02-2012, 11:19 AM   #482
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Quote:
Originally Posted by amalgrover View Post
have you read the beginning of this thread...the whole purpose of this thread is basically to tell people like you that the 0.5 seconds between shifts that you go rich from having a bov isn't going to hurt anything...AND...as long as the valve is installed, adjusted, and working properly, you aren't going to hurt anything.


btw...the reason factory cars haven't ever used a bov is mostly due to emissions. i bet the evap systems, tgv systems, or the air pump systems are for performance too huh ...guess we probably shouldn't delete those since there clearly is a reason that the manufacturers put them on there.
Right because everyone who had a bov adjust's it on a regular basis
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Old 05-02-2012, 12:58 PM   #483
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if it is a quality valve that is properly installed and adjusted to begin with, it shouldn't need anything more than a cleaning and seal swap every once in a while to keep things running like new. not sure what valve you have tried that was causing you to do this, but if a valve is constantly having to be adjusted, then it isn't working or installed properly...OR...better yet, there are probably some issues with the tune that are being highlighted by the valve.



...this is all assuming it isn't some ebay knockoff and actually is a quality valve...
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Old 05-02-2012, 01:47 PM   #484
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Personally I never ran a bov...but pleanty of my friends have had issues with constant leaking many brands and no eBay knock offs. Ether way ill stick with my stock bpv ...and thanks for the info though
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Old 05-02-2012, 02:43 PM   #485
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Quote:
Originally Posted by calical6905 View Post
Well it works pretty well on my car. Hate all you want
you probably also smoke cigarettes. does the same thing to you as a bov to your car.

they both provide zero benefit
they both make you look/sounds "cool"
While there is no direct statistical evidence, they both kill you(your car) slowly over time

Bov's benefit people running a lot of boost. enough boost that the stock one cant handle.chances are if you are running a turbo that the stock bov cant handle, you are no longer running a maf and at that point it doesn't matter if it is leaking or not (kind-of)

just like u say "haters gana hate" I can say "ignorant fools gana be ignorant"

//rant//
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Old 05-02-2012, 04:04 PM   #486
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Quote:
Originally Posted by jayman4312

you probably also smoke cigarettes. does the same thing to you as a bov to your car.

they both provide zero benefit
they both make you look/sounds "cool"
While there is no direct statistical evidence, they both kill you(your car) slowly over time

Bov's benefit people running a lot of boost. enough boost that the stock one cant handle.chances are if you are running a turbo that the stock bov cant handle, you are no longer running a maf and at that point it doesn't matter if it is leaking or not (kind-of)

just like u say "haters gana hate" I can say "ignorant fools gana be ignorant"

//rant//
I challenge you to provide specific reasons as to how a properly tuned BOVs damage your car.
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Old 05-02-2012, 04:14 PM   #487
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Quote:
Originally Posted by Bug-Eye WRX View Post
I challenge you to provide specific reasons as to how a properly tuned BOVs damage your car.
I challenge you to provide a percentage of people who actually properly adjust, maintain, tune their BOV's. I also firmly believe many people buy inexpensive, low quality valves that will leak no matter how well its tuned, adjusted, whatever.

People who properly adjust, etc their QUALITY BOV usually don't post about how sweet the sound is and that's why they got it.
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Old 05-02-2012, 04:30 PM   #488
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Quote:
Originally Posted by jayman4312 View Post
I challenge you to provide a percentage of people who actually properly adjust, maintain, tune their BOV's. I also firmly believe many people buy inexpensive, low quality valves that will leak no matter how well its tuned, adjusted, whatever.

People who properly adjust, etc their QUALITY BOV usually don't post about how sweet the sound is and that's why they got it.
^^^^This x1000000000000000
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Old 05-02-2012, 09:04 PM   #489
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vf22Bugeye11, jayman4312
Well I am glad these two could join in a talk about how much they hate aftermarket BOV's. This is the kind of stuff that helps people out around here
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Old 05-02-2012, 09:09 PM   #490
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I swapped an aftermarket one on after the Motor build in order to ensure the pressure was held better. Of course it stayed completely recirculated.

Vent to atmosphere is just an attention grabber.
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Old 05-04-2012, 04:27 PM   #491
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Quote:
Originally Posted by calical6905 View Post
vf22Bugeye11, jayman4312
Well I am glad these two could join in a talk about how much they hate aftermarket BOV's. This is the kind of stuff that helps people out around here
We help people make good decisions
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Old 05-04-2012, 11:45 PM   #492
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Quote:
Originally Posted by jayman4312

I challenge you to provide a percentage of people who actually properly adjust, maintain, tune their BOV's. I also firmly believe many people buy inexpensive, low quality valves that will leak no matter how well its tuned, adjusted, whatever.

People who properly adjust, etc their QUALITY BOV usually don't post about how sweet the sound is and that's why they got it.
I COMPLETELY agree with you. ANY part (mostly) done incorrectly can be bad for your car.BOVs are reliable and non damaging, when done CORRECTLY. And garbage parts will always be garbage parts...
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Old 05-12-2012, 08:38 PM   #493
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This should be stickied on every car forum known to man.
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Old 06-01-2012, 08:08 PM   #494
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Quote:
Originally Posted by amalgrover View Post
have you read the beginning of this thread...the whole purpose of this thread is basically to tell people like you that the 0.5 seconds between shifts that you go rich from having a bov isn't going to hurt anything...AND...as long as the valve is installed, adjusted, and working properly, you aren't going to hurt anything.
Quote:
Originally Posted by Bug-Eye WRX View Post
I challenge you to provide specific reasons as to how a properly tuned BOVs damage your car.
I know you both mean well but you're gut feeling on this subject is wrong.

You can check for yourself by connecting your laptop and viewing the fuel trims. The RPM you most often shift at will see a rich condition and the ECU will subtract fuel. The next time you go through the same RPM without shifting it will run lean. There will often be knock events which will pull timing. It will see this new lean condition and add more fuel for the next pass. This dance between removing fuel, running lean, removing timing, adding fuel, adding timing results in lower power that most of you aren't sensitive to notice. Logging has proven it on multiple cars.

I would hope for you to do this on your own car since the only way I can prove it is with a screenshot. I don't have to explain why running lean under boost is a bad thing right?

Atmospheric blow off valves don't belong on a street Impreza. We have a few dedicated track cars (three of which have over 500WHP) that use an atmospheric blow off valve. We don't drive them at partial throttle so it doesn't go through the rich/lean/advance/retard dance.

There have been multiple cars come into the shop that we have converted back to recirculating valves. If the owner wasn't happy with the approved driveability we wouldn't get payed.

The ONLY exceptions are if you are using a blow through MAF and the blow off valve is before it or a stand alone (both of which are also uncommon on a street car)

And so you don't think I'm pulling your leg about the race cars here are the pictures of them. So NO U
http://i41.tinypic.com/261bz9w.jpg
http://i49.tinypic.com/1zxv4t3.jpg
http://i42.tinypic.com/sy09af.jpg
http://i48.tinypic.com/2e1dn9t.jpg
http://i49.tinypic.com/35n9gr9.jpg

Last edited by ciper; 06-01-2012 at 08:14 PM.
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Old 06-02-2012, 05:56 AM   #495
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Just installed my HKS SSQV IV kit on my 04 wrx.. I was getting really bad boost response before like it was hard to make the boost early on. Now that is solved obviously something was wrong with my stock valve then again the stock one is 8 years old so that could of been the problem

Will recirc it eventuall but its fine now. Idle is perfect no change
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Old 06-03-2012, 03:38 PM   #496
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Quote:
Originally Posted by ciper View Post
I know you both mean well but you're gut feeling on this subject is wrong.

You can check for yourself by connecting your laptop and viewing the fuel trims. The RPM you most often shift at will see a rich condition and the ECU will subtract fuel. The next time you go through the same RPM without shifting it will run lean. There will often be knock events which will pull timing. It will see this new lean condition and add more fuel for the next pass. This dance between removing fuel, running lean, removing timing, adding fuel, adding timing results in lower power that most of you aren't sensitive to notice. Logging has proven it on multiple cars.

I would hope for you to do this on your own car since the only way I can prove it is with a screenshot. I don't have to explain why running lean under boost is a bad thing right?

Atmospheric blow off valves don't belong on a street Impreza. We have a few dedicated track cars (three of which have over 500WHP) that use an atmospheric blow off valve. We don't drive them at partial throttle so it doesn't go through the rich/lean/advance/retard dance.

There have been multiple cars come into the shop that we have converted back to recirculating valves. If the owner wasn't happy with the approved driveability we wouldn't get payed.

The ONLY exceptions are if you are using a blow through MAF and the blow off valve is before it or a stand alone (both of which are also uncommon on a street car)

And so you don't think I'm pulling your leg about the race cars here are the pictures of them. So NO U
http://i41.tinypic.com/261bz9w.jpg
http://i49.tinypic.com/1zxv4t3.jpg
http://i42.tinypic.com/sy09af.jpg
http://i48.tinypic.com/2e1dn9t.jpg
http://i49.tinypic.com/35n9gr9.jpg
unless you are ALWAYS shifting at the exact same rpm every time, the correction would be stft (un-memorized) not ltft (memorized). long term fuel corrections (memorized) aren't really applied in open loop, which means that the ecu wouldn't run lean under boost unless you are running a cl/ol delay long enough to allow you to make it to a significant boost and rpm before switching to open loop.

also, even with a recirc valve, you will see the stft go negative (pull fuel) every time you do a gear change due to the throttle tip in and tip out feature in the ecu. if you log the af corrections (stft), this is easily seen. if you do a pull and shift at 4000rpm, the stft will go negative (pull fuel) when you lift off the throttle, and then do another pull and shift at 6000rpm. if you look at that log, it doesn't go lean on the 6000rpm pull at 4000rpm because it pulled fuel there on the previous pull. this is because it was just a short term correction and not a memorized long term correction.

the short term and long term fuel trims are ALWAYS moving around due to changes in fuel quality, fuel type, altitude, temperature, barometric pressure, etc. not all of these changes are memorized, only the ones that are repeated and consistant. if the ecu memorized ALL the fuel corrections it made, the fuel trims would jump around a ridiculous amount and it would be a pointless feature.

while i will agree that adding an atmospheric valve adds to the amount of movement you will see in af ratios and stft and it may not be as ideal as a recirc valve, i disagree in that it causes lean conditions under boost when changing the shift point.
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Old 06-04-2012, 06:56 PM   #497
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Quote:
Originally Posted by amalgrover View Post
while i will agree that adding an atmospheric valve adds to the amount of movement you will see in af ratios and stft and it may not be as ideal as a recirc valve, i disagree in that it causes lean conditions under boost when changing the shift point.
I appreciate the informative well written response. I think for the most part we are in agreement.
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Old 06-07-2012, 11:57 PM   #498
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running with an atmospheric BOV is quite bad, but how bad is it to run with a hybrid one?

how is it possible to a bov to leak? unfixed hoses?

Last edited by Muh; 06-08-2012 at 01:36 AM.
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Old 06-09-2012, 03:32 PM   #499
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a hybrid valve has the same issues as a full atmospheric valve in terms of going rich between shifts, but depending on the valve, it either just reduces these conditions or reduces the frequency of them. the only reason the hybrid valve would be any better is because it would improve driveability in the light throttle conditions by recirculating or blowing off less air than a full atmospheric valve would. essentially though, the hybrid is going to do the same things to the motor that a full atmospheric one would.

a bov will leak if the valve sticks open from being dirty, if spring pre-load isn't set correctly and is allowing it to open when it shouldn't, or if there is a seal that is bad on the valve allowing air to leak through
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Old 06-13-2012, 11:15 AM   #500
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My first post! And it has to be on the BOV thread. =)
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