E.T. Slip

An E.T. Slip, also called a timeslip, is an official printout given to drag racing drivers after each run down the track that shows detailed performance data including their reaction time, speed, and elapsed time from start to finish.

When a drag racer completes a run, they drive to a designated area where they receive their E.T. Slip. This small piece of paper serves as an official record of everything that happened during those few seconds on the track. Think of it like a report card for that specific run, showing exactly how the car and driver performed.

The "E.T." in E.T. Slip stands for "elapsed time," which is the total time it took the vehicle to travel from the starting line to the finish line. However, the slip contains much more information than just that single number. It includes multiple timing points along the track, giving racers a complete picture of their performance from launch to finish.

One of the most important pieces of data on a timeslip is the reaction time, which measures how quickly the driver responded to the green starting light. This doesn't count toward the elapsed time but is crucial in competitive racing where races can be won or lost by thousandths of a second. A perfect reaction time is 0.500 seconds, meaning the driver left exactly when the light turned green.

The 60-foot time is another critical measurement that shows how quickly the car covered the first 60 feet of track. This number tells racers how well their car launched off the starting line. A poor 60-foot time usually means problems with traction, tire pressure, or launch technique, while a good time indicates a strong start.

The slip also includes intermediate times at various distances like 330 feet, the eighth-mile mark (660 feet), and sometimes the 1,000-foot mark. These checkpoints help racers understand exactly where their car is performing well or struggling. For example, if the 60-foot time is good but the 330-foot time is slow, there might be an issue with gear shifting.

At the finish line, the E.T. Slip records two final measurements: the total elapsed time and the speed in miles per hour. The speed is measured by sensors called a speed trap located just before the finish line, showing how fast the car was traveling at the end of the run.

Racers use their timeslips for tuning and improving their vehicles. By comparing multiple slips over time, they can see whether changes to their engine, transmission, or suspension are helping or hurting performance. Many drag racers keep binders full of old timeslips to track their progress throughout a season or even over years.

In bracket racing, a popular form of drag racing, the E.T. Slip becomes even more important. Drivers predict their elapsed time before the race (called a "dial-in"), and the goal is to run as close to that prediction as possible without going faster. Going faster than your dial-in is called "breaking out" and results in automatic disqualification, even if you crossed the finish line first. The timeslip is the official record that determines the winner.