Scrutinize runs

To get real accurate, you need to do what I call equalizing the ET’s based on 60’ time differences. There are only 2 reasons why ETs change. 1- From horsepower changes, and 2- from Traction changes. If the change was from horsepower, the ET will progressively change throughout the run. ET changes from Traction will be the same all the way down the track. To separate this you need to find the run that had the best 60’ time and reference it for the rest of the runs. As the weather goes up or down by 100', I figure the 60’ time should have changed by .001 seconds on gas. The 60’ times will need about 200’ for a change of .001 seconds on Alcohol. So if you are comparing two runs on gas, where the one you are comparing to the reference run has 200’ worse air, then you add .002 to the reference run’s 60’ time that is what it should of been. I usually write the 60’ time that it should have been above the real 60’ time, and put it in parenthesis. Then subtract the difference. This difference needs to be subtracted from the finish line ET so you are looking at the real ET’s without the influence of run to run 60’ time variances. Write the corrected finish line ET above the real ET and put it in parenthesis. If the 60’ times look reasonable in relation to each other, just leave them the way they were. Next we should look for any runs that were done at near the same Density Altitude and pick the one with the lowest ET. That means the one with the quickest ET made the most out of the available air. So scratch out the bad run. Likewise if you have two runs that produced close ET's, but there was a couple hundred feet difference in Density Altitude, the one that was done at the higher Density Altitude is the better run because the one with the better air should of speeded up but it did not. So scratch out the bad run. The rough rule of thumb for Gas is that you should pick up a hundredth with every 100’ to 190’ of better air. The faster the car, the more air it takes to make the ET change by .010 seconds. Alcohol usually takes 225’ to 400’ for the ET to change by a hundredth. It takes a greater change of air for the faster cars like a Super Comp car as opposed to a 12-second Bracket car.