I saw an SS beat a TT buy more than 5 car lengths, but this is just what I saw. I am sure there was age factory between the two cars. I also have never seen your Z in action, and so it may beat an SS. What I know is that I drove a both a TT Z and a the SS and I felt that the Camaro was faster now that is because of the torque, but I also look at the speedometer and the Camaro climed a little faster as well. The fact that the top was down may have also given it a faster feel. This is all from what I felt and saw. I have still thinking of doing the tt swap on my car but I am not sure if I will see a diffrence in speed between the SS and the TT. -David