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"The BIG BOV thread" (Where all bov question threads get merged)

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#1 · (Edited by Moderator)
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.

Thanks!


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.


Links for BOV info:

Sinister's BOV FAQ

Wikipedia

Unabomber on Nasioc

Davenow on Nasioc





 
#7,386 ·
Vent it into the cabin through the firewall. It'll sound super-cool albeit a bit loud. I think this is what the racers use to keep tabs on what their turbo is doing, (or is that ricers? tunas maybe?)
 
#7,387 ·
Actually, I ordered the Turbosmart WRX/STI Plumb back unit today. Not sure if I need it, but some money was burning a hole in my pocket and I have a wait between shifts with the 18-G. On the chance that the stocker wasn't flowing the air fast enough I ordered the Turbosmart unit.

Not meaning to advertise for rallysport, but I don't yet know how to post pics here. New on this forum.

http://www.rallysportdirect.com/sho....html?osCsid=a0010835da9a307151b674c53368ff46
 
#7,388 ·
Yet another BOV

Yes i know all of you will kill me but this is just a question so please do not bash a fellow rex owner. Does anyone know if there is a BOV that does NOT hurt performance, i am looking to buy a blitz DD BOV supposibly it will work with stock ECU and keep it happy any input would help. btw i have a 06 wrx tr.
 
#7,393 ·
look up a Forge BOV
 
#7,394 ·
Trainrex said:
And to think you have the reputation of knowing how to use them. :p
:whoa:
DAMN. BURNNNNN!!!
 
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