I have a '87 Turbo II with a street ported motor and full T4 turbo upgrade.. Im using a Greddy Type R BOV but im not sure what spring is in it. I currentley have the BOV releasing back into the intake system, and of course I want to release into the open air... Does anyone know if the Greddy STIFF spring will allow me to do so?

 

Sure...
Do you hear compressor surge?&nbsp Those things don't usually like to open up until you start hitting 20psi of boost!



-Ted

 

The spring does not have anything to do with where the BOV dumps to. I have the same BOV on my car and it vents right out into the atmosphere.


I get some compressor surge or backturbine but that keeps all the little old ladys out of the way......hehehe

 

Don't BOV's open under vacuum?

 

That "stiff" GReddy Type-R BOV spring is sooo stiff that you need significant boost pressure to crack the valve open.&nbsp Even with the vacuum pull on the diaphram, it still won't open.&nbsp Yes, you are right about vacuum pulling the BOV open, but in this case the stiff spring holds it closed unless running significant boost...


-Ted

 

Just curious, what does compressor surge sound like?

 

Pull off the vacuum line off the BOV and find out.
It sounds like a fluttering bird...
Ever watch any WRC races?&nbsp They run no BOV, and it's all compressor surge.



-Ted

 

well if i set it up to vent openly i cant get the car to idle.

 

Are you still running the original AFM or the 89+ AFM?

 

the original.. waitingfor my haltech or tec3... still debating on which to get

 

I love the sound that makes, but doesn't it hurt your turbocharger?

 

Im sure its not the best thing for the turbine but what other choice do I have, The type S blowoffs are too small for a large turbine and I think they blow off too much besides it would look dumb to have a big turbine and intercooler piping with that little BOV mounted in there....