Hey guys, great site, ive been reading here for a while, but didnt feel worthy of posting until i got the nelson tune. well i got it friday and i love it. one question though, why do i still lose to my friends truck? I have an 04 ecsb z-71 with 58,000 miles, with intake, exhaust, e-fans, vette servo, nelson 91 tune and a tb bypass. he has an 04 ecsb z-71 105xxx miles and the same exhaust as me and a superchips 91 tune. the only thing is, i have 285/75-16 tires, he has 265/75-16. he slowly but surely pulls on me to 100, then i take off and leave him. why with so few mods does he come out ahead? sorry for the long first post!