Something is definitely up. Looks like you were braking before you crossed the line. Your short times aren't too bad for someone that doesn't go to the track very often. If you can cut consistent 2.2X 60's, you should be in good shape at the end of the track. But 78 & 79MPH(10 & 11MPH slower than your best MPH) are SLOW! You should be around 90-92 every run.
Mark