This is my first turbo car..I have a 2005 WRX. I am trying to find out if I am suppose to be able to hear the blow off valve release or not....I have done some research and not found out that answer. can anyone help.....thanks

You can find you cars enthusists in plenty at the North America Subaru Impreza Owners Club. Lots of Forums and info.

 

http://www.nasioc.com/

 

P.S. Yes, the Blow off valve, if doing it's job after letting off the throttle quickly is noisy.

No, You shouldn't. Infact this is one thing that most young kids will do first is put an aftermarket BOV on to showcase their turbo. This actually robs HP.

-Chris

No, You shouldn't. Infact this is one thing that most young kids will do first is put an aftermarket BOV on to showcase their turbo. This actually robs HP.

-Chris

So do they have a recirculating BOV then?

I don't know about that. I think that the stock BOV just isn't noisy enough for you to hear over road noise and/or engine noise.

I'm no expert though, I've only gathered this info from more seasoned WRX owners on bulletins such as this one.

I found this for you on NASIOC.

 

"The stock BOV is more of a ABV. ie an Air Bypass Valve. When at vacumn, ie not on boost, the valve is open and allows air to go "forwards" by bypassing the turbo/supercharger into the throttle body. When at boost, the BOV closes up, allowing boost to be built, then when you let off the gas, the vacumn takes back over, the valve opens up again and the excess pressure (boost) bleeds back off to before the supercharger/turbocharger, basically equalizing the pressure of the system."

 

So, yes it is a recirculating BOV.