I'm in the Viper club here in Kansas City and they do a free dyno day every year for paid members. Took the Viper and the ISF since I plan on ordering the Joe Z intake and exhaust. (Want to hear the exhaust in person before ordering). Any way during the day there were about 20 Vipers so I was definately the runt but did get 3 pulls in. All stock with half tank of 91 and half tank of 93.