I know for a fact my Performance tune is faster than the EXTREME tune on my Superchips. maybe too much fuel slows them down....:shrug:Robinhood said:Well I got my SCT looney tune in the truck and my friend wants to race. He got a 03 6.0 with a bully dog. Well I got beat. He just walks away from me. He don't blow past me but walks away pretty good. What gives? Also I am only seeing 20 psi of boost?