I got the Brewer tune, and it basically did nothing except lock out the DoD. Brewer says it's fast enough to beat a stock GXP by half a second. I have no other GXPs to race against. I need an actual HP increase.
I know Trifecta used to support the LS4, but doesn't anymore. Is there any way to get the Trifecta tune from one of you guys? I have the HP Tuners unit.