thanks great info if you dont mine me asking i a have a few more q,s. what octane did you run with that 15psi tune ont he kb chip. What size pulley is the 15psi.And what were your torque #s and at what rpm were the torque and hp peaks.lastly how does that beast feel and run on the street? i am just trying to justify getting this over pullying my eaton to run cooler charge and lower boost cause of the 91 octane and hot weather here in vegas with just as much and more hp.thank you greatly.KENZILLA said:Maybe i can help....I have a KB at 15 psi using the KB flip chip (as of now, i am about to have a new chip tuned in order to make more power and also it does run rich on this tune from KB) When i put the KB on it made around 563hp on the KB tune for the 15 psi. I few months later i hit the dyno again and tried the 21 psi pulley with the kb chip on tune #2 and used race gas. The car ran lean at i think around 3500 to 4000rpm and we had to get out of it. At that point i had a tuner come in and burn a chip for me and tried it again. Well, it was close to the same results. It went lean at close to 5500 to 6000rpm, but not before it registered close to 670hp. We tried a few more runs and same result, LEAN. So we put the kb chip back in and stayed on the 15 psi set up. The conclusion is that to go over about 15 to 17 psi will need a custom chip tuned and probably larger injectors. I will probably go to 60# injectors myself. The other mods on the car at the time of this tune was a CAI, pro chamber, cat back, BAP, and gauges to monitor boost and fuel. Maybe this will help.