What is the activation pressure for a STI BOV?

I have a ej25 with a wrx turbo, sti intercooler and have a sti BOv on the way

 

Not sure what you asking here. But the STI bpv will function the same way as the standard wrx unit. Someone correct me if I'm wrong, but I believe the STI bpv will hold a little more bost than the WRX unit. Otherwise, they function the same when under 20psi.

 

I am asking at what pressure does the BOV actually blows the pressure out of the intake manifold. Right now I am looking around 6 ish psi. I am still getting all the bugs worked out of the whole motor

 

the pressure from the manifold releases when you let off the gas. as soon as you close the TB all the pressure releases through the BOV/BPV.

 

What are you talking about? There's no set pressure that opens up the bpv. It's activated by the throttle body closing shut. It doesn't matter how much boost is built up. When you let off the gas pedal, the bpv releases the excess pressure.

 

Right, it releases the excess presure. my question is simply at what pressure is it released

 

You're not getting the answer you want because you're not asking the right question.

There's no "release pressure"... ever... stop asking that.

You need to read about how a bov/bpv works before you go any firther with this.

My only assumption is that you've confused a bov with a wastegate. A wastegate will open and close in a very loose relation to boost pressure. It's main job is to prevent the turbo from generating too much boost. A bov's job is to prevent any boost from flowing back to the turbo when the turbo slows down (ie. when you let your foot off the loud pedal) The bov keeps pressure in the lines until it is no longer needed. There is no pressure that activates its release.

 

Better learn how your car works before you start messing with it. You don't know what a BPV is for clearly.

 

You are correct, a wastegate does bleed exhaust gas to keep the turbo from making too much boost. the wastegate makes it so that the intake, or any other part of the engine, is not damaged from too much pressure. The BOV can also help if the boost spikes too quickly for the wastegate to activate, the turbo to slow down, and stop generating pressure. If you are at a high boost, then suddenly let off ot the gas, the bov HELPS by bleeding the intake pressure of into the atmosphere before it can do any damage to the engine. this is because there is force on a valve, makin it move. when it moves, air escapes by this valve, GETTING RID OF EXCESS PRESSUREYou can almost say that it is an emergancy or a back up type of system. all i want to know is when this emergancy system kicks in. I ask this b/c I have seen many dirrerent BOV's that kick in at different pressures. As you can see, I am not the best with words, but I do actually know something about cars, especially forced induction ones. this is not to say that i know every thing about them, because i don't. BUT, I am not a dolt.

 

I would never rely on the bpv to save the engine from boost spikes.

As far as "How much back pressure needs to exist for the bpv to release?", I would guestimate around 5-6psi since any less than that really doesn't have a damaging effect on the turbo.

I completely undestand your question now. Thanks for the clarification.

 

no preblem, sorry for the confusion. I just can be bad with words sometimes. thank you for the answer.