I never shift with the tach. I even tell myself to look at it and I just never do as I shift by the sound and feel of how the eng is pulling. I feel that I can tell when its peaking and when to shift. I will look at it going through the traps sometimes and sometimes on the starting line I look at it. But I basically have never shifted with the tach even when I bracket raced a 4-speed car and I was and still am very consisdent. Ron