This is the big BOV thread. If you didn't find this thread, you didn't search.
This thread is where all BOV question threads get merged into.
The quote below in this first post is from our BOV info sticky and contains links to some very explanatory BOV information. Please take the time to explore the links before you ask repeated questions.
A stock WRX/STi comes with a BPV (Bypass valve) which is a vacuum-actuated valve designed to release pressure in the intake system when the throttle is lifted or closed. This air pressure is re-circulated back into the non-pressurized end of the intake before the turbo.
An after market blowoff valve (VTA) does basically the same thing BUT unlike the stock unit it releases air to the atmosphere (giving you the loud sound). Some people see an after market BOV on a stock WRX as being in poor taste (probably due to the fact that it is basically a noise maker that really as no other benefit), while others simply find the sound very attractive.
Proponent opinions notwithstanding, there is a small mechanical downside to having an after market BOV (VTA) on a stock WRX. The problem comes when releasing air to the atmosphere that has already been metered by the mass airflow sensor. When the BOV releases (blows off), the ECU will be injecting the wrong amount of fuel into the cylinders. The engine temporarily runs too rich (meaning too much fuel is injected into the cylinders). This temporary rich condition isn’t typically THAT harmful, but it may cause bucking or hesitation on lift-throttle as well as some other concerns outlined in the links below.
i had the gfb and got sick of it. Now im starting to miss the pssssssshhhhhhhh sound. Eli- what is the lowest rpm it blows off at? I normally shift at 2800 when regular driving. Will it blow off at that low of rpm?
i got sick of it blowing off every shift in 100% atmosphere mode. But im starting to miss the sound. Maybe just the type h bov (not rfl) would be better for me...
i got sick of it blowing off every shift in 100% atmosphere mode. But im starting to miss the sound. Maybe just the RFL bov (not type h) would be better for me...
whoops, i got them backwards. Its adjustable like that? I am sold as of now. Now to order my stoptech's, and my TXS intake and BOV.
How does the adapter work? Does it bolt on, or does it need to be welded?
whoops, i got them backwards. Its adjustable like that? I am sold as of now. Now to order my stoptech's, and my TXS intake and BOV.
How does the adapter work? Does it bolt on, or does it need to be welded?
Its not really adjustable but the washers make the piston harder to move, so if you shift low it really makes no noise, makes less/more noise according to throttle/rpm.
Its a complete bolt on, like a 5 minute install FOR ME which means it should take like 2 seconds for you. ill see if i have any pics up close for ya.
pop off the stock, put the flange thing on there. (the 2 bolts you see on the sides) then the bov secures on to the flange via a few small bolt type things that go around the base of it. (you use an Alan key to secure them, so I dont know the exact correct word) Then plug up the hose back to the intake with the black plug that is supplied in the adapter kit. Put the hose on top of the bov and secure, done.
Oh and you probably want to lube up the piston with some WD40 to prevent it sticking open or closed.
im tired, im about to head to sleep, but this past week i havent gotten to sleep till after 3 and woke up at 8 for class or earlier for work. Just not a good week, couldnt sleep well. But I got work in the morning, so ill have to go pass out now, yay. later all. Anythin else ya need on the rfl just lemme know corey.
i don't have one, but i've heard them and they are LOUD. like a whip crack X 100. of course, you run the risk of running rich, same as any BOV though. i have the Forge 100% atm and i like it alot. loud, but not crazy loud.
im looking for a BOV that wont blow off under normal conditions (shifting below 3k) thats why the TXS type h rfl is good- i dont care how loud it is when im on it. How much did you pay for your forge and from where?
To be honest with you, I've had the forge and the HKS... and the HKS has remained on...
I took off the forge after 2 weeks. it got annoying, REAL quick. It leaked boost (yes you can fix that with different springs, but that still didn't work for me)... and it just wasn't as good of a sound as the HKS.
To be honest with you, I've had the forge and the HKS... and the HKS has remained on...
I took off the forge after 2 weeks. it got annoying, REAL quick. It leaked boost (yes you can fix that with different springs, but that still didn't work for me)... and it just wasn't as good of a sound as the HKS.