I picked up a used one from Fritz and installed it today. I have two questions. Whats the smaller nipple on the bottom for and what does the "softer"-"harder" adjustment do?

I believe it makes the spring harder and softer. Harder for higher boost levels. If the spring is too soft it will leak under boost, too hard and it will not release



Or something like that

Ok, I thought maybe it effected the whistle or some dumb ****.

What about the nipple?

i got the same one just use the top nip i dont know about the bottom

how do you avoid the whislte peep sound that it makes?

you have to adjust the spring perfectly

bottom nipple is for high boost applications, it allows the boost to hold the valve closed.

Buy a dif BOV, lol....

The adjustment nut is to stop compressor surge. It may also effect the sound a little.



Don't worry about the other nipple

if the nut is too loose will u leak boost?

yea thats what happened to me, it takes a little while to adjust the nut perfectly. too loose and it leaks, too tight and it wont blow out any air.

Thanks Sean https://www.nopistons.com/forums/pub...IR#>/smile.png

sounds like a new-b question dave! just busting hahahahha https://www.nopistons.com/forums/pub...#>/biggrin.png

Welcome, if you need more info on it let me know I will get you the hookup diagram for it.

No worries, hey how would I know. It didn't come with any instructions that say what the adjustment is for. Anyway, whats with you wrecking cars at PFS and then quiting and not telling me about it? That sounds like newbie driving to me.. HAHAHAH Just bustin https://www.nopistons.com/forums/pub...IR#>/bigok.gif

That woudl be cool Sean, if nothing else we could pin the thread in the FAQ after that. I would like to know the exact purpose of the 2nd nipple.

http://www.roadraceengineering.com/p...y-stypebov.JPG



Install the new bypass valve onto the I/C pipe flange with the gasket supplied with the valve.



The GReddy valve has two fittings for small vacuum lines on it. The top fitting is for the same hose that went to the original stock bypass valve, the hose that goes to the intake manifold. The lower fitting is normally left open. It is a vent for the lower chamber of the valve.



On some cars with large turbos, compressor surge at light throttle lifts can be further reduced by connecting the lower fitting to a pressure source. Typically a fitting is added to an I/C pipe between the turbo outlet and the valve.

The GReddy Type S bypass valve is adjustable. To make the adjustment, looses the 10 mm nut on the top of the valve. Using a 3 mm Allen wrench, rotate the small screw in the center. Looses it all the way out until you feel no tension on it. That is the maximum looseness possible. With the screw all the way flush with the top of the nut, that is fully tight. Normal adjustment for most cars is right about in the middle (see photo above). If the valve is too loose you may loose boost pressure. The valve will close slowly and will make a little squeak sound at the end. If it is too tight, you will hear compressor surge. Surge sounds like a "JUhh juhh juhhew" sound when you let off the throttle. It may sound cool but it will damage your turbo. That is the sound of air bouncing off the throttle plate and going back out the turbo as it is also being pumped in... too tight