D-Man: correct me if I'm wrong.... I've noticed the same 'woosh' sound after the DIY air filter mod... it seemed to me to be when the wastegate would be releaseing pressure, due to the up-shift/lowered rpms... what you're saying is that if the turbo is building so much pressure that is has to release it with the wastegate, that we're damaging our turbos? Elaborate on this a little if you would... thanks!