Blow off valve (soft/hard)

[4g63telantra]

I just picked up a turbo smart blow-off valve. At at the top of it, its says hard and soft. Just wanted to know what if i run all the way hard or all the way soft? Does it matter how many PSI im running?

 

[Patterson]

I just picked up a turbo smart blow-off valve. At at the top of it, its says hard and soft. Just wanted to know what if i run all the way hard or all the way soft? Does it matter how many PSI im running?

Yeah it does matter. The "hard and soft" refers to the stiffness of the spring inside the valve. Turning the bolt or screw to 'hard' will stiffen the internal spring and vice versa. How much boost are you running? this matters because if the spring is too soft, the valve may leak under high boost. but if it's too stiff, the valve wont react correctly....

 

[Lottaboost]

Yeah what he said plus
if it is too hard you can get turbo chirp or stall because the BOV will not let off enough boost between shifts

 

[vtracer20]

i'm running @ 15psi on my 14b, i turn my greddy to a little harder from previous possition and it sounds sick

 

[blcknspo0ln]

screw it all the way tight... then turn it about 3 full turns loose. drive the car and go WOT in 2nd gear.. BOV... if you can hear flutter that means its still compressor surging. get out of the car and turn it 1/2 turn loose.

repeat.

once you get close to the "perfect" adjustment, start fine turning at 1/4 or even 1/8 of a turn.

repeat.


this will take a couple runs, but at least you know you're BOV is tuned for YOUR car.