Cars that drag race do not use overdrive as you need torque to get a good et and using overdrive would reduce your torque. A crossfire manual car would only use the first 5 gears and the auto would only use the first 4 gears. And to get your best time you want to reach your max power or redline just after the 1/4 mile. Drag racing is all about the combination of torque and horsepower. Horsepower affects your mph or trap speed, while torque affects your et. That is why drag racers look at trap speed to see if they made more horsepower, as the trap speed will be almost the same weather you smoke up your tires and get a slow et or get a good holeshot and get a low et. So changing your gear ratio by having smaller tires will help your et by giving you more torque but your horsepower always stays the same and will not raise your trap speed, but usually lower it slightly. If your trap speed goes up you made more horsepower and you can not make more horsepower by putting on smaller tires. As I said before I agree that the et of 12.98 is possible but not the 113 mph that is too high, as I have not seen many mph over 108. He must be making more horsepower or the 113 is a misprint or his car is a factory freak

try this link and put in 3,440 for the cars weight, my best estimate for the car and a 200 lb driver. Use the et method and trap speed method and it will give you respective hp numbers.
http://www.dragsource.com/index.php?...s&calctoview=4
try this one too.
http://www.dragsource.com/index.php?...s&calctoview=5