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-   -   GREDDY TYPE S BOV..nippples (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/greddy-type-s-bov-nippples-544807/)

JDawG707 05-29-06 12:49 AM

GREDDY TYPE S BOV..nippples
 
Just wondering if the sound will differ with the 2 nipple's. Has anyone tried to do the bottom nipple? my friend has it on his 240 and it flutters with the bottom nipple, and mine is on the top nipple and it sounds like 1 big Squeky Pshh..Comment of experience plz...dont want to try it myself until i get a okay.

JDawG707 05-29-06 08:28 AM

Bump^^

DaleClark 05-29-06 09:45 AM

Your buddy is an idiot :). The bottom nipple goes under the BOV's diaphragm, the top nipple goes to the top of the diaphragm. When you let off the gas, if you have vacuum going to the top nipple and boost pressure pushing against the BOV's valve, the BOV will release and do it's job. If you have vacuum to the bottom nipple, it will HOLD IT CLOSED, and you'll get compressor surge - that's the keen noise your buddy is hearing. Compressor surge damages turbos and slows turbo response down.

The reason for the bottom nipple is twofold. First, you can use it as a pop-off valve, which is a dumb idea and gets pretty advanced. The second is to add a pre-throttle body boost source, which helps in very large boost applications.

Regardless, ignore the bottom nipple. Hook it up to the top one and be done with it.

Dale

smg944 05-29-06 09:50 AM

dale have you ever tested the type s as a pop off valve? if so how was the outcome, i have an extra one, maybe ill use it for safety like this.

DaleClark 05-29-06 09:54 AM

Popoff valves are really a bad idea. When they open, you let the turbo spin itself up VERY high as it's unloaded, and it's really hard on the turbo. A proper boost control system is far better than a pop-off valve, IMHO.

Dale

JDawG707 05-29-06 10:33 AM


Originally Posted by DaleClark
Your buddy is an idiot :). The bottom nipple goes under the BOV's diaphragm, the top nipple goes to the top of the diaphragm. When you let off the gas, if you have vacuum going to the top nipple and boost pressure pushing against the BOV's valve, the BOV will release and do it's job. If you have vacuum to the bottom nipple, it will HOLD IT CLOSED, and you'll get compressor surge - that's the keen noise your buddy is hearing. Compressor surge damages turbos and slows turbo response down.

The reason for the bottom nipple is twofold. First, you can use it as a pop-off valve, which is a dumb idea and gets pretty advanced. The second is to add a pre-throttle body boost source, which helps in very large boost applications.

Regardless, ignore the bottom nipple. Hook it up to the top one and be done with it.

Dale

THANKS! alot now i can make fun of him...


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