bov question

[san supra]

the bov is borrowed from a fellow supra owner and has been sitting for 7yrs.
its a greddy and is vented to atmosphere (i know, i know its just temporary).

the problems
while slowing down in gear i can hear the bov whistle/open all the way down to 1k.(tighten spring right?) does this normally happen and its because its not recirculated that i hear it?

i get compressor surge on low boost even when im still on the vacuum side of the gauge. (so loosen the spring right?)

at high boost (10psi) it is fine.

should i just loosen the spring to fix the surge or does it opening while slowing in gear mean its bad? because besides the surge i have had no problem with driveability.

sorry if i left info out, i just cant think right now.

 

[Alec]

Adjust it so it's closed at idle and blows off completely at full boost.

 

[san supra]

Adjust it so it's closed at idle and blows off completely at full boost.

yes sir that is what i did.

at idle i adjusted it until it stayed close and it does hold my full boost but is it wrong that it opens as im slowing down in gear and doesnt open when i have less than 2psi of boost, causing surge?

 

[JesseH]

what greddy model is it? and is it a real one?

 

[san supra]

its real and its a type S
it did 7yrs of sitting

what do yall think?
if i loosen it more it wont close at idle

 

[JesseH]

its real and its a type S
it did 7yrs of sitting

what do yall think?
if i loosen it more it wont close at idle

OK, the type-s has 2 ports on it. That is the current BOV I have, I have never had any surge problems. You need to hook up that second port, that is beneath the purple top to a boost reference. IE intercooler pipe, tap into the wastegate line etc. That should solve your problem, the second port is designed to make the BOV respond faster. With the second port disconnected mine will surge a bit at really low throttle.

 

[hvyman]

^ you sure about that. i have a greddy type-s too and mine is loosend all the way with zero compressor surge at all at 8psi on 57trim. it was my under standing that if you hooked up the smaller port it needed to go back into the turbo inlet and it would make it just sound differently.

 

[JesseH]

^ you sure about that. i have a greddy type-s too and mine is loosend all the way with zero compressor surge at all at 8psi on 57trim. it was my under standing that if you hooked up the smaller port it needed to go back into the turbo inlet and it would make it just sound differently.

yes. here is one of my old post with a diagam.

I have the Type-S too. I love the thing out of the others I have used. I also have the bottom port hooked up to a boost ref. The reason why that second port is there is to use the positive pressure to push up on the valve while the vacuum source pulls. By doing this it creates a faster valve response to fully remove compressor surge. I left the bottom port off at first with my 60-1 on the car and got surge in lower boost levels. With that port hooked up it took care of it all.
Heres a pic of how it works:

 

[hvyman]

wow thanks. so where did you hook up the second port at?

 

[JesseH]

wow thanks. so where did you hook up the second port at?

Any spot between the turbo housing and the throttle body will work.

 

[Poodles]

One of the reasons I prefure pull style BOV's as boost actually holds them closed.

 

[san supra]

great info guys thanks!

the original owner didnt use the second port either so that sounds like the solution to me.

 

[Suprapowaz!(2)]

Yeah, I never used the second port and it did wistle while my car idled down. I never thought to hook up the second port. Give that a try.