2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

Greddy RS blow off valve won't ... blow off :P

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Old Jun 25, 2009 | 07:59 PM
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Greddy RS blow off valve won't ... blow off :P

Anyone have experience with this? I am pretty new to the whole turbo thing, so I don't know all the details of how the turbo stuff works.

What I do know is what compressor surge sounds like. And that it's bad.

After installing the Greddy Type RS BOV I have had bad compressor surge at all boost levels.

I have tried playing with the adjust screw by making it go all the way to soft. Didn't do anything. So I took out the bigger of the two springs in the BOV. After doing that, things were better but not great:

When I am boosting 8 psi or so in 2nd or 3rd gear under 4K revs, I get bad compressor surge whenever I close the throttle. If I am boosting 5-10PSI at high revs in 3rd gear or higher, the BOV goes off properly.

Is this the way BOVs work? They only work when there is a lot of air going through the pipes, and they DONT work at low engine speeds? Why?

Everytime I let off the throttle and I hear the CH-CH-CH-CHHHhhhh coming from the turbo I feel like god kills a kitten. HELP ME SAVE THE KITTENS!
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Old Jun 25, 2009 | 08:06 PM
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you got the vacum line hooked up? a bov wont work without one
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Old Jun 25, 2009 | 08:18 PM
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Originally Posted by Hypertek
you got the vacum line hooked up? a bov wont work without one
yaya right behind the throttle plates
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Old Jun 25, 2009 | 08:23 PM
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hm.. there are two valves that come out of the BOV on the greddy like my type S.. i use the top nozel connected to the intake manifold and it works fine...



get it working and trade me for my Type S .. i want to change for the sound.. check out my thread

https://www.rx7club.com/3rd-generation-rx-7-1993-2002-parts-99/greddy-type-s-bov-847695/
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Old Jun 25, 2009 | 08:35 PM
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hook it to the bottom nipple on the front of the UIM. It pulls vacuum from the plenum area instead of just one rotor (like that nipple on the side of the UIM a lot of people use that goes to one primary runner).
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Old Feb 21, 2010 | 12:03 AM
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I was having the same problem before my engine popped..
I think there was too much spring tension to let the diaphram push out.
Try removing the inner spring, like this.
http://www.evomoto.com/tech_info.php?tPath=1&tech_id=7
I did the same thing to my RS,
I'll let you know if it works when I get my car running again.


edit, oops I guess you allready tried removing the large spring?
did it work any better after moving the vac source to the front of the UIM?
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Old Feb 21, 2010 | 06:13 AM
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my friend had the same problem on his bov. read that the spring on some of them are too hard and wont open up correctly. i think you can get it replaced with a different spring rate.
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Old Feb 21, 2010 | 06:48 PM
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make sure the vacuum source is the same as what the stock recir valve is, are there 2 nipples on the Bov try the other one

My bov did the same thing until i swapped the nipple on the bov
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Old Feb 21, 2010 | 07:08 PM
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The Guy has had the car running for a year now!.( it has a 13bre in it!)
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Old Feb 22, 2010 | 06:43 PM
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Haha.. yeah, my car runs, and runs well now.


For those interested.. as it turned out, the problem with my BOV was none of the above: in the gasket I had made for it, I forgot to cut an opening to let the air go thru LOL

Boy did I feel stupid when I unbolted it. In fact, I think I unbolted it a number of times before actually noticing the gasket was just a plain sheet of gasket paper with no opening.

But seriously, this does call the quality of that gasket material into question when the BOV STILL went off properly at 8psi in a higher gear.
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Old Feb 22, 2010 | 06:48 PM
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haha good job.
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Old Feb 22, 2010 | 06:50 PM
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i had this issue a while back. my car was running shitty and i didn't know what was going on. turns out my turbo was seized!
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