I have on 03 Cobra with a Procharger p1sc2 with 14#s of boost making 625rwhp the other mods are mac long tubes, h pipe, magnaflow cat back, 60#injectors, dual focus pumps, 4.10 gear, accufab throttle body, Vortech aftercooler upgrade, IMO i love it on the 03 cobra with the irs rear you can leave with less boost and really hook nice, on the other hand if you switch to a solid rear axle you can leave at a higher level I have no times yet because I have a vert and wont let me run at our track without a 6point cage. I am going to be upgrading to 19#s soon and should be up towards 670plus i hope... I think its more personal preference than anything. Goodluck with your car !!!!