did the standard rx7 have a blow off valve/ presure release valve? Even if the vented back into the air filter?
because the guy who sold me my car took the one in there out. Turbo flutter is crazy. but i hurt everytime i hear it. Just wondering what you guys think of turbo flutter.

 

Yes, it had a stock BOV, which was routed back into the turbo inlet.

Why anyone would take it off is beyond me - unless they were installing an aftermarket BOV elsewhere in the system. Crazy stuff...

I don't have any experience or much info on turboflutter though. I suppose this is when you need a BOV or your current one can handle the amount of increased air flow - so the air is slamming back into the turbocharger blades and putting excess pressure on the thrust bearings. If I am correct, this doesn't sound very nice to me either!!!

 

You need a bov on any turbo car or else the turbo will **** the bed way before anything else.

If you are in a pinch and dont have 200 bux to spend on an aftermarket BOV, check this out:

This BOV is used on stock saabs, porshce, and any other car with bosch parts in it. The BOV is larger than the stock rx7 bov (about 30-40% larger) and also has an added feature of not messing with the airflow meter like aftermarket BOVs. This bov is not good for anything over 15 psi (it opens like a pop up valve). Best thing you can buy for 26 bux.

http://www.thesaabsite.com/900new/90...turboparts.htm
Its called a "cutoff valve" on the site.

 

That's the BOV that I use. It's great.
BTW- it only doesn't mess with the AFM is you DON'T have it open air vented, just routed back into the intake between the AFM and the turbo.
I have a check valve on mine, and its open air vented.

 

wow this is awesome thanks for the heads up

 

well the loosers in australia seem to love this stuff. Most of the top drag rotors will blast you if you talk to them about turbine back spin/ slowing down. I personally don't follow this.

does anyone think of a BOV as a waste of money?

 

You can buy aftermarket recirculating BOV's, but most people seem obsessed with the open-vented noise.

 

The way most people use them they are a waste of money. All factory turbo cars come fitted with BOV's simply to eliminate the noise caused by compressor surge. At factory (and mildy raised) boost levels the amount of surge isn't enough to warrant a bigger valve. It's not until you really start pushing a lot of boost you need to use a bigger BOV to minimise surge and protect the turbo. Most people fit them not because they need a bigger one, but because they simply want the noise.
BTW, has anyone noticed that even though they don't improve performance at all, and just make noise and attract attention, no-one ever refers to open-vented BOV's as rice?

 

Hell, I'll call it rice. If you are running stock boost, and have an aftermarket BOV, you officially have a rice mod.

 

many stock turbo cars had no BOV at all (stock nissan 280zx turbo for example). Some of the really old school turbo kits didn't even have wastegates let alone BOV's...the turbo produced the boost it could build and you'd have to regulate it with your FOOT!!! some people even prefer stock BOV's to aftermarket...on my GVR4 pushing 22 psi, we simply use the standard mitsubishi valve that we crushed a bit to prevent boost leak. Works great, sounds nice...not very loud but you know it's there

 

My vote is on transient throttle ...