Im new to the site here so I may be way behind you guys, but have all of you with GTP's checked the adjustment on the bypass valve on your S/C. The factory guys do a poor job getting it correct and usually leave a lot of HP just spinning around instead of being turned into BOOST. I adjusted mine and noticed big gains in power, it made enough difference that my wife even said WOW when she drove it the first time after I worked on it.