I think those of you who are really interested in going faster should have another (faster) driver you trust drive your car. With you in it timing them, or DAQ so you can overlay your info.
For those who haven't seen that done...here's an example.
From some friends:
Paul vs Paul vs Eric. My best from this weekend in Blue 1:25.012 , my best from April Summit in Black 1:26.014 and Eric in my car from April Summit in Red 1:24.054
You can really see how a different driver can drive the same car differently.