Went and checked the tailpipes, no bananas... Or at least what I could see with the help of my iphone as a torch. Popped the hood and checked the belt. I find it to be nice and tight. I can actually remember hearing this "noice" or like turbo release noise before installing the PSK aswell. It occurs when in 1st push pedal to floor and a bit of wheel spin and the let go of pedal. Then its like boost release sound...