I have the same problem. I have a 1.33 60 ft. and run 108 mph most of the time and ran 109 once. According to the calculator on Wallace Racing web sight I should be running 112 mph and 2.5 tenths faster.

1.33 60 ft,6.21 at 110.59 in the 1/8, pump gas small block,2950lbs,drag radials,mufflers and driven to track ...