Blow off Valve ???
 

Okay, so I just got a new BOV for my z31, I welded the flange to my (j)?pipe about 3" form the TB. I hooked the vacuum line to the intake and it has 18-20 in HG at idle and no pssssst :wasted: with 10psi of boost as I let off. So I was reading all over the web and on here... So, some say that the BOV should be opened at idle, some say that it should be opened only with vacuum + boost???... Then, if it's opened and high vacuum, I know that the Z will not idle right...I think I got a BOV to big for the boost I'm running...??? After looking online, a RS BOV is for 20psi boosted cars. ( could the spring inside big to big?) I pick up a "TURBO BLOW OFF VALVE SSQV + 2.5" ADAPTER UNIVERSAL-BLUE Type RS-II" I've read "How BOV's work" that did help some, but one says opened at high vacuum and the other is only with high vac + boost. No 1 answer... this has only one vacuum line to it. Attachment 6733

did u try adjusting it? SSQV's are supposed to be made pretty universal so low to high boosting cars could use them

adjusting??? Are you talking about the bolt on top??? If so, I have it as far out as it will go...

the bolt on its ass end. you should have to adjust the tension on it for different boost levels. arent their instructions? lol

:confused: instructions? whats that??? No instructions in the box... you now e-bay LOL... so I had it a part, and found the a valve insidie was not in right... danm that cheap $h!t... I just got it in and 1-2-3 it works... real short lived, less then 1 second... now I know that could be the spring...

have u tried putting the bolt the other way since u have it all the way up top? but you do get what you pay for >_<

If I move the blot down more, then the bolt will press down on the spring more...

did it come with different springs? u got an e-gay special??? not good. never get knock off e-bay stuff especially something thats as good as the HKS design cant be cheaply reproduced properly.

Take a good pic of how it's mounted on your car & post it here.

Maybe this will help:

http://i60.photobucket.com/albums/h8...components.jpg

So here you go... after driving today, I had to have boost of 8-10psi for 2 secs or so just to get the BOV work (super short). I read that a RS BOV is set form 12+ up to 24psi boost. This is a push pull valve, so (I think) that 20 HG vacuum + 8-24psi of boost= open... ??? and if I would of got the type R BOV, then 20HG vacuum + 3-12psi = open...??? So, do I need to find a sping that opens with less boost???

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not sure when this was posted. But have you Modified your POV cause stock is set for like 8Psi so it would be opening first causing your BOV to never open. If not, grind the top off, then you push down on that steering wheel shaped piece and twist it unlocks and put some washeres on bottom of shaft leading to the Valve then put spring back on and that Top steering wheel shaped piece and push and twish to lock back in. About 3 washeres sets for about 12psi or just put a stiffer spring in there and your set.

All that trouble just to make a "psssshhhhht" noise? :104:

no its all that trouble to relieve charge pressure to preserve the compressor blades. BOV's wouldnt be that popular if they didnt serve an actual purpose.

That's kind of arguable, though, isn't it? I've heard many say that they're completely unnecessary.

thats completely not arguable. if you run 5psi only then sure you can get away with no BOV, they also help reduce lag between shifts, relieving the charge pressure will stop compressor surge, compressor surge will try to suddenly stop the spinning of the turbo which leads to lag since it has to spool again and also damages the compressor blades. its a fact. not arguable in any manner. whoever said that they are unnecessary is retarded. however many modern turbo cars come with recirculation valves (which is a blow off valve but recirculates the pressure back into the intake piping not the charge piping) and in that instance they are unecessary since there is a device already performing their function. however many stock ones will reach their limit really fast and at high boost will leak and/or not provide adequate pressure release.

Actually, we had this discussion a long time ago at 300ZXClub, and quite a few people said it wasn't necessary, IIRC. I could be remembering wrong. So, you're saying a BOV makes a turbo faster?

nooooo... im saying it stops the pressure once the TB closes from trying to escape back out the turbo the wrong way. its physics! if the air were to start to track back out through the turbo it would cause the turbo to slow down rapidly between shifts and damage the compressor blades, this is called compressor surge. with a BOV the air escape out through it between shifts so theres no resistance put on the turbo so its just free wheeling between shifts. thats all it does! an 300zxclub, what a joke. i hear so much about that place..... its where retards go to be superior :D

I see. Yeah, I was banned a long time ago. I didn't get along with those idiots. LOL

My z31 has compressor surge like a mofo. It's just as loud as a bov! I really need a bov, but I dont feel like taking that pipe off, looks like a royal pita.

I hear a little surge when I let off, but not bad. But then, I'm still running stock boost, for now. I had plans to put an IC in it and crank it up a bit, but then I got into a bunch of shit and decided it would be best for me not to be tempted to haul ass anymore than I already do, at least until I'm off probation.