I have recently installed a turbosmart kompact dual port blow off valve on my car. I have made it full atmospheric. My car is running 20 PSI. I have two questions: 1. Under lower boost levels eg < 8 PSI, I will get the turbo surge/flutter sound, anything above that will get the bov sound. Is this normal or should I adjust? If so tighter or more loose? currently have 4 shims. 2. Also wanting to know, is it possible for the bov to leak of make the car lose power? And if so, would this be caused by the BOV being adjusted too tightly or too lose?