i have an 06' GXP w/cold air intake,new MAF 83mm polished throttle body, magnaflow down pipe with hi flo cat. and chip. Last dyno put me at 355hp with 342 tq. (i will scan chart and put in when i have a chance). after all this I couldn't wait to get out and run some times! imagine my suprise when I could not achieve consistant times better than stock. My problem, I could not hook up! I am going to hit Ebay to see if I can buy some slicks. I will keep everyone informed.