I found this on Nasioc I dont have a BOV anymore but i thought i would copy and paste it for anyone else that may have questions. the write up was done by Clark, a Tuner from like arizona or someplace down there. -------------------------------------------------------------------------- Most aftermarket BOV's seal at idle. Some dont... THe proper way to adjust your bov is as follows: Drive the car in 3rd gear. Apply enough throttle to get the boost gauge to 0. Snap the throttle closed. If you hear the valve blowing off at 0 or under zero (vac) the preload is to loose. You should only really hear it if you snap closed at 2-5 psi. If your valve lacks the adjustment simply add washers to add more preload. I find the TXS valve needs 3-4 Quarters or about a dollar in change to hold tight. Most TXS (knock off is worse) will crack open at 18 psi or above. You might not notice it but trust me.. I have stood and watched the valves crack while on the dyno. If you add to much preload then you will get compressor surge or a chirping sound during a shift.
