Its more of a flutter than a whistle, I have my bov off completly and it sounds insane. ← Compleatly off what are you doing with the plumbing. Is it back into the intake?? Wouldnt you be loosing boost. ← the std BOV plumbs the air back int othe intake. by taken the BOV off it realse there out to atmosphere. ← So wouldnt you loose boost by doing this???. Isn the BOV there to seal the intake whilst under boost then release the pressure when the throttle closes??