They all look about the same to me. My G-tech meter will give you HP in a 1/4 mile run. I had ran 4 or 5 runs all at around 12.7, I went and had the resonator removed & installed the SL55 "Y" & hose's. I did not do any runs between the resonator & "Y" mod's, but I dropped to a 12.3 and the G-tech meter showed a 27 HP increase compared to before the two mod's mentioned. That's at the wheels and the wind hitting the front of the car. All of my runs that I have done with the G-tech meter the launch was the same, TC off-small burn out, TC back on and floor it. That type of launch sure does make a bad 60' time, but you are alway's comparing apples to apples that way.