Now I"m still pretty new to this but I've heard that hearing your turbo whistling is pretty common when you start opening up the intake and exaust right? I've still got a bone-stock intake and my turbo was whistling pretty loud, so I started checking all my intercooler and turbo connections. Two of them provided basically no resistance to a wrench, they turned VERY easy. I tightened all of them up including my exaust clamp on the turbo and WOW what a difference!! That truck has steam likes it's never had!! How much whistle should you expect before starting to become leery of a problem? Under WOT the truck actually barks the tires shifting into 2nd gear now it's pulling so hard! :clap: