I have a TurboXS-H BOV. Its rated at 10-25 PSI. I am only running stock boost levels right now (I want to break the new motor in a little more before I bump it up) So, My exhaust is Inasanely loud! and I can't hear my BOV go off between shifts. Is there another way besides hearing it? to tell if its going off? Vacuum gauge or anything like that? ..... what is the downside to it not going off at such small boost levels? And if my BOV is rated at 10-25 ... what happens to the boost under 10? will it not get released? I am thinking i might want to clip the BOv spring a little bit to loosen it .. But i would like to test if its going off right before I do that.

Any sugestions?

Thx,
Robert

 

No ideas on this eh?

 

Get somebody to stand in front of the car with the hood up. Rev it a couple times and they should be able to hear it.

And God Damn, your exhaust must be ******* retardedly loud.

 

No they won't. He won't get any boost with out moving.... he will have to drive by.

 

haha! it sounds like a Harley! ....

I thought it will only boost under load. Your saying the BOV should go off in neutral? no load? can anyone confirm this? And if it goes of with no load & at low-no boost won't it leak boost pressure like a siv when I hit real boost? that just doesn't sound right to me.

BTW: its only really loud over about 4-5K but thats when I am hitting optimal boost and I really need the BOv I can't hear

 

The Type H BOV is for high pressure systems .. and its not intended to be real loud .. and Im certain it won't be that loud at only 6 Lbs. but it worries me that I hear nothing.

 

it's loud as crap on a wrx even at 5 psi. So just call nathan,mark, and phil up and ask them. They're awesome guys!

 

You sure its the Type-H ... not the Type S, or type RFL?

 

if it's from a sound clip of a WRX's blow off valve going off it was a Type RFL.

http://alltrac.net/tuning/blowoffvalve.html

from that site.

Your BOV should be going off when you're off the gas between shifts ect so your exhaust shouldn't be drowning it out? Even when I didn't have my downpipe bolted to my exhaust very well (i could damn near see between the two) I could still here the factory one...

*edit* Where are you sourcing your vacuum source from? The way my car was set up when I bought it from the sketchy man he had it sourced off a Tee that had one regular and two restricted ends to it.. needless to say.. with it like that the BOV wasn't responding at all. Just something to think/look at I guess.

 

I am pulling it from the original BOV Vacuum line hookup.

 

you should be able to see it open when reving in "N".. have somebody look at it while you rev.

 

I am going to play with it again tommorow. I still think it may be a little to tight for the low boost im running ... but I will see. Its awful damn stiff. But I always heard if they are not blowing off the surge you would hear a strange noise from the Turbo, I don't hear anything odd from the turbo either.

But that again I can't hear **** but my full 3 inches!

 

The "big" TurboXS BOV works just fine and blows off smooth. A buddy of mine has one, and it works great.

It's not SUPER loud, but you can hear it fairly well - it sounds pretty good.

If you're getting surge, something's wrong with the BOV. Get into boost, then take your foot off the throttle. If you're surging, you'll feel the flutter and maybe hear it. If it is smooth, you're fine.

I wouldn't worry about it.

Dale

 

Well I have the type RFL one but not installed yet. I was wondering the same thing...if I run low boost if I will have a problem. But then I figured that if I am running a low boost setting I must not be in a hurry so I shouldn't be seeing any boost.

 

The only real difference between low and high boost blow-off valves is the stiffness of the spring. A high boost BOV has to have a very stiff spring to keep from leaking at high boost pressures.

Many BOV's that are high boost/race BOV's are too stiff to drive on the street - you get compressor surge at low boost. Mind, I'm not talking about the "low boost" setting on a boost controller - just times when you're only at 1/4 throttle and building around 4-5 pounds of boost.

The TurboXS BOV's are really nice units - even the big BOV (the H I think it's called) blows off smooth at all loads.

Dale