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Discussion Starter #1
I searched, but didnt really come up with a straight answer. When I build up boost and release off the throttle, there is a flapping sound. Where is this pressure being released from, the bpv? I just listen to some audio clips of supras, but they always have the woosh and I just have a flutter. One thing to consider would be that the line that is suppose to go to my boost gauge has nothing on the end (its not attached to the gauge). I'm not in the same city as my car so I cant just go out and attach it, and when I was by it the other weekend, I didnt have my boost gauge. So is that a pretty big boost leak that could be causing the sound?
 

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1993 RX-7
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278 Posts
When the throttle plate closes, all the built up pressure has nowhere to go. The factory bypass valve will recirculate that pressure back into the accordian hose. If the bypass valve is not functioning or is overburdened (too much boost) then the pressure will go back to the turbine causing that noise, its called compressor surge. You need to check if your bypass valve is working properly, and possibly upgrade to an aftermarket unit.

As for the boost gauge, you should cap off the line if it is open, that is a boost leak.
 

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Discussion Starter #3
I have a bosch 110 waiting to be installed, but I'm at about 10-11 psi (with that boost leak or possibly more).
 

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Discussion Starter #5
lol I know, I'm only home by the car like 1 maybe 2 weekends a month, but this summer is coming and I'll finally have every day with it!!!!!!!

How can I tell if it is compressor surge. I just read up on it quick and I got the feeling that "wg chatter", bov's, and compressor surge all sound similar. I can feel anything in the car (like it back down) when it happens. Its only the sound. And what should I do if I put my new 110 in and it still happens?
 

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Now with less BHG...
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409 Posts
Sounds similar to a worn out spring in the BOV/BPV... Mine did the same thing for the longest time, until I replaced it
 
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