Took me a long time to find some good doco on BOV's to tune mine properly.. I will share it with you..
At idle, if you feel a slight breeze coming out of it, then it needs to be tightened till you dont feel a slight breeze... At 2k rpms, if you feel a slight breeze coming from it, tighten 1-2 whole turns more..
If its the opposite and you dont feel no breeze both times.. loosin the shit until you do and tighten slowly until it stops.
Thats all folks.

now for some bad advice:
always run from the cops.