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Noob bov question

912 Views 5 Replies 4 Participants Last post by  RikRong, 
reed1285
may i state once again im new to the world of boost so take it easy on me if this is a complete noob question. anyways how come when im in neutral in my car and rev it up to about 4k or 5k rpm the bov doesnt open up, but when im cruisin around town it lets out even the slightest amount of pressure...even when im just put putting around town. doesnt that have to do with how hard or soft the spring is adjusted to on it?? idk please shed some light on this for me turbo veterans. its a greddy rs bov by the way
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DrftReadySR
You wont create as much boost in neutral as you would while putting the engine under load.

Say your tuned to 11psi, you will only boost about 8 while revving in neutral.

Your BOV should still let lose the air even at 1psi. Soften up your BOV by1/8th of a turn then test it, keep doing it until its just right.

Dont soften it up too much.
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reed1285
alright thanks man i will soften it up just a touch then see what it does
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RikRong
Drift Ready pretty much hit it on the head. In neutral, the car probably won't even show 8psi. I think mine barely breaks 0 when there is no load on the motor. If your car is idling fine, I wouldn't mess with the stiffness of the BOV. It doesn't necessarily have to blow off in neutral. Mine just barely opens in neutral, so little that I can't even see the piston move, I can only hear the air escape. If you have it set to blow off too much in neutral, then it's not going to hold pressure under full boost.
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Joel 180
RLong9514 said:
If you have it set to blow off too much in neutral, then it's not going to hold pressure under full boost.
Click to expand...
A BOV working properly will never open under boost. Its not the spring that holds it shut, its the equal pressure between the boost behind the BOV piston and the signal line above the piston. The spring is there to shut the bov as it goes back to idle vacuum.

If your spring is too soft it wont close and your car will stall out. If its too hard it will never open at all.
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RikRong
I am not sure if you are saying my description was wrong or just too vague? Either way, Joel spelled it out a lot better than I did.
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