what do blow-off valves do exactly? besides makin a cool sound....

 

I'm not an expert, but here's what I know. BOVs release the presure that builds up after the turbo and before the engine when your revs drop (like when you shift ). If they weren't there, the turbo would explode or something. WRXs come stock with a recirculating BOV, so the pressure is released back to the intake before the turbo, so the air/gas charge is reused and not released to the air. The aftermarket BOVs that make noise replace the stock one and vent the air/gas charge to the atmosphere instead of the intake. IMO, that's not good. But if you like the sound enough...

 

its there to prevent compressor surge,when you build boost and let off the gas the throttle plate closes there is nowhere for the air to go but back in the turbo so the bov helps that...... as for blowing up it wont it aint good for your turbo but it wont make it explode

 

lol

 

so are bov's worth getting?

 

for the sound and the looks you will get... yes

love my blitz dd

 

your car comes with one. you just can't hear it because the blown off air is returned to the intake system instead of being vented out to the atmosphere. your cars fuel system expects the air to be returned and if you change this setup you will adversely effect the fuel system. this gets even worse if you couple it with a poorly designed aftermarket intake. your stock bov is good for over 18psi. i'd just leave it alone.

jason

 

...that's what I was getting at in my post...stock is mo betta than aftermarket BOV unless you feel the need to show off everytime you shift...

 

I realize that the stock BOV is more than adequate. However, I'm considering upgrading to a VF34 and then going with the GFB BOV set to 50/50. Would that be enough recirculating to keep the fuel system happy? Besides, I'm pretty sure that you need an aftermarket BOV when going to a VF34. Thanks for the help guys.

psycho

 

you dont

 

I am almost positive a bov is not necessary with a VF34. I know you dont need on to run the Cobb VF34 map http://www.cobbtuning.com/wrx/access...2093%20oct.txt.

 

The divertor valve also "pinwheels" the compressor wheel/turbo durring the shift reducing lag as well as keeping some pressurization in the intercooler/charge pipes.All of this equals better performance.

 

dont get an aftermarket bov...the sound of an afermarket bov is too addicting (sp) once you hear it you will probably not wanna put back on the stock bov. (in my own opinion) using the stock bov is the best for your car.

oh and you dont need an aftermarket bov to run a vf-34.

for larger turbos that do excede(sp) 18 psi, there is an HKS bov thats 100% recirculating.

 

Do you have any experience with that 100% recirculating HKS BOV? What is the name of it? I have a buddy with an Audi and a 100% recirculation BOV that is loud as hell. Obviously, performance is most important to me, but you have to admit that it's a cool damn sound. Thanks for the info on the HKS BOV.

psycho

 

no i dont have any experience with the HKS recirculating bov http://www.hksusa.com/products/?id=798
its just the HKS ssqv bov with attachment. or the HKS Racing bov II http://www.hksusa.com/products/?id=759 i am pretty sure you can use this bov + HKS recirculating kit to make a 100% recirculating bov that holds up to 43.44 psi. (with some minor modification with the return hose of course )


i have the txs rfl bov,and at the moment borrowing my friends HKS bov w/out recirculating attachment.