My brother has an ATI 12# S/C on his 92Z with a 355 and A4. Everytime he drives, even at cruising speed, his blow off valve is opening and closing, making this terrible squeeking noise. It sounds as though the blow off valve is iopening and closing very rapidly and is very annoying. What have some of you other S/C cars done to upgrade (type, part #, etc)? Are there any web pages to describe any process (welding, etc) for an blow off upgrade. Thanks,

Kyle

 

Yo Bro, the only thing I saw was the vortech mondo and there regular one, they were both like $200.00. I can't believe no one has a blow off valve on there supercharged car and can't post something. Somebody is looking at this post as you can tell by all the viewing. C'mon someone has to have some input.

Brad

 

does it look like thishttp://cam355z.cz28.com/photo2.html . Thats the one I have, and it seems to be a pile. There are a couple otions, I have heard good things about vortech Mondo. Try a search you should find some good results.

 

does it look like thishttp://cam355z.cz28.com/photo2.html . Thats the one I have, and it seems to be a pile. There are a couple otions, I have heard good things about vortech Mondo. Try a search you should find some good results.

 

Yes, that is the same one. iT is a pile from the experience I have had it on my brother's car. I don't think it would be too hard to fab up a better blow off valve, even from some of the import/turbo guys options. Any ideas? Thanks,

Kyle

 

What I see pictured is not a BOV, it is a surge valve.

I found some info here:

http://www.thirdgen.org/techbb2/show...hreadid=226034

 

I don't know why the surge valve would be squeeking... never noticed any sound like that from mine. Lubrication maybe?

I use a TurboXS RFL BOV in conjunction with my ATI surge vavle. I've had good results with it. Instalation is simple.. weld a flange that comes with the BOV onto one of your pipes, mount BOV onto flange, and supply it with a vacuum line from the manifold.

 

Old turbo volvo's (740's) and some older saabs have nice bosch metal bypass valves that I have heard are very good replacements for the cheap plastic units. You can get one at most junkyards pretty easily. I found good information about that kind of stuff on some turbo mustang sites. When I put the vortech on my car I was going to try one out.

 

The "squeeking" is the BOV opening and closing at a high rate during cruising conditions. If the car is at a steady rpm (say 2000 rpm while cruising at 60 mph), then the BOV will make the constant noise.

I assumed a BOV and surge valve are the same thing. The purpose of both is to relieve extra "boosted" pressure when the throttle blades are closed, to help prevent pressure build up in the piping which may cause damage to the compressor wheel in the S/C. Both are vacume operated. Does anyone have anything other than the stock valves on their cars? Thanks,

Kyle

 

I've got a Greddy blow off valve...pic was emailed to you...hope it helps...
Adam

 

i have a bosch one (PN 0280142108) on my car. it's plastic with a metal diaphragm. It's pretty quiet, but you can definitely hear it pop open on shifts.

It's reliable up to 12 psi and it starts to leak at around 16psi due to pressure against the diaphragm.

Since all my tubing is custom anyway, I just tig'd a nipple on the aluminum intake tubing and hose-clamped it on via a piece of heater hose.