Drag racing, a race between two cars starting from a complete stop for a distance of 1/4 mile (1320 feet) depends heavily on the first 60 feet of the race or the launch. The technique used for the launch varies greatly depending on how the car is equipped. The type of transmission, the wheels that are driven, the tires, the power, the suspensions and the preparation of the track all play a key role on how to get the best possible launch from the car.
The improvements in the time needed for the car to travel the first 60 feet along the track have significant implications on the final ET (estimated time). As a general rule, the 60-foot time improvements have increased 2x on the final ET. For example, a Dodge Viper GTS running a 12.2 @ 120 MPH in 1/4 mile with a 60 foot time of 2.0 can make significant improvements to its 1/4 mile times for a better pitch. If the Dodge Viper GTS is able to cut .2 (two tenths) of a second is 60 feet time, covering the first 60 feet in 1.8 seconds, it is a final ET for 1/4 of a mile it would be about 11.8 @ 119 – 121mph. Other examples can be found by looking through the thousands of 60-foot records in the http://www.dragtimes.com drag the racing database.
The best possible throw is obtained by obtaining the optimal balance of the application of the maximum amount of power on the ground with the lowest number of wheel turns. If too much power is applied during the launch and the wheels turn, the resulting 60-foot time will be short. The same goes for not applying enough power, getting the car’s engine bogged down and slowing the car down.
When launching a car with an automatic transmission, a technique called power braking is used. After correctly staging the car in the parking lane of the drag strip, hold the brake with one foot while slowly applying the accelerator with the other foot. The engine speed (revolutions per minute) of the machine should increase slowly to the point where the machine will start moving or the wheels will start spinning. Hold both the brake and accelerator pedals just below the point where the car starts moving or spinning the wheels. When the lights of the Christmas tree reach the last amber light before the green, lift the brake and slowly push down on the gas accelerator. The correct RPM for the launch will be different for each car depending on the variables mentioned above. It starts conservatively with the first launch and continues to increase the speed at which the car is launched in subsequent races. If the car starts spinning the tires after the launch, lower the launch RPMs and try again.
When launching a car with a manual gearbox, stop completely after the car has been staged correctly. Press the clutch all the way down with one foot while pressing the accelerator down with the other foot, increasing the engine speed to a steady moderate level for the first launch. Raise the clutch pedal to the point where the machine is about to start moving and hold both pedals still. When the lights of the Christmas tree reach the last amber before the green, slowly release the clutch while quickly applying the accelerator enough to quickly launch the car, but not too much to induce a large rotation of the wheel. It starts conservatively with the first launch and continues to increase the speed at which the car is launched in subsequent races. If the car starts to turn the tires too much after the launch, lower the launch RPM and try again.
To obtain better launches and further reduce the time of 60 feet, the use of radial drag or full slick tires can be used on more powerful cars that have difficulty launching at any rpm on normal road tires. Drag radials and full slicks usually require a depletion to heat the tires and clean them of debris for optimum performance. A burnout is a rapid rotation of the tires of a car while the car remains relatively stationary.
All four-wheel drive (AWD) cars are generally the easiest to launch because the engine power is distributed over 4 wheels rather than two. Rear-wheel drive (RWD) cars typically launch better than front-wheel drive (FWD) due to the transfer of weight to the rear wheels during launch, causing an increase in traction. If the car is equipped with adjustable aftermarket suspension, specific adjustments for endurance races can be made to increase the weight transfer to the drive wheels.
The preparation of the runway springboard also plays an important role in how and how hard cars can be launched. The launch area is usually prepared with traction compounds to increase the viscosity of the runway. A well-prepared track will surely help you lose 60 feet and score in less than 1/4 mile.
During breaks and cooling periods between drag racing, make detailed notes on how you launched on the back of each time window. These notes can help you diagnose startup problems, refine subsequent launches, and show improvements in your search for The Perfect Launch.