Drag Racing – The Perfect set afloat
Drag racing, a contest between two cars beginning from a complete stop over a distance of a 1/4 mile (1320 feet) depends heavily on first 60 feet of the race, or the set afloat. The technique used for launching varies greatly depending on the how the car is equipped. The kind of transmission, which wheels are being pushed, tires, strength, suspension and track preparation all play meaningful roles in how to go about getting the best set afloat possible from the car.
Improvements on the time it takes for the car to travel the first 60 feet down the track have meaningful implications on the final ET (estimated time). As a general rule, improvements in the 60 foot time, are magnified by 2x on your final ET. For example, a Dodge Viper GTS that runs a 12.2 @ 120 MPH in the 1/4 mile with a 60 foot time of 2.0 can make meaningful improvements to it’s 1/4 mile times by obtaining a better set afloat. If the Dodge Viper GTS is able cut .2 (two tenths) of a second off it it’s 60 foot time, by covering the first 60 feet in 1.8 seconds, it’s final ET for the 1/4 mile would be around 11.8 @ 119 – 121MPH. More examples can be found by searching by the thousands of 60 foot records in the http://www.dragtimes.com drag racing database.
The best possible set afloat is obtained by obtaining the optimal balance of applying the most amount of strength to the ground with the least amount of wheel spin. If too much strength is applied during the set afloat and the tires spin, the resulting 60 foot time will be poor. The same goes for not applying enough strength, thereby causing the car’s engine to bog, and having the car limp off the line slowly.
When launching a car with an automatic transmission, a technique called strength braking is used. After properly staging the car at the drag strip’s staging lane, firmly keep up down the brake with one foot, while slowly applying the accelerator peddle with the other foot. The car’s engine RPM (revolutions per minute) should slowly increase to a point where the car will either start to move or start spinning the tires. keep up down both the brake and accelerator peddles just below the point where the car is starting to move or spinning the tires. When the christmas tree lights reach the last amber light before the green, lift off of the brake and slowly push the gas peddle all the way down. The correct RPM to set afloat at will be different every car depending on all of the variables mentioned earlier. Start conservative with the first set afloat and keep increasing the RPM at which the car is launched at during the later runs. If the car starts spinning the tires after the set afloat, lower the set afloat RPM and try again.
When launching a car with a manual transmission come to a complete stop after the car is properly staged. Press the clutch in all the way with one foot while pressing the accelerator peddle down with the other foot, raising the engine RPM to a continued moderate level for the first set afloat. Lift up on the clutch peddle to the point where the car is just about to start moving and keep up both peddles nevertheless. When the christmas tree lights reach the last amber before the green, slowly release the clutch while quickly applying the accelerator peddle enough to set afloat the car quickly, but not too much to generate a large amount of wheel spin. Start conservative with the first set afloat and keep increasing the RPM at which the car is launched at during the later runs. If the car starts spinning the tires too much after the set afloat, lower the set afloat RPM and try again.
To acquire better launches and bring down 60 foot times already more, the use of drag radial or complete slick tires can be used on more powerful cars that have trouble launching at any RPM on regular street tires. Drag radials and complete slicks usually require a burnout to heat up the tires and clean them from debris for optimum performance. A burnout is a rapid spinning of the car’s tires while the car stays comparatively nevertheless.
All wheel excursion cars (AWD) are typically the easiest to set afloat because the engine’s strength is distributed to 4 wheels instead of two. Rear wheel excursion (RWD) cars typically set afloat better than front wheel excursion (FWD) due to the move of weight to the rear tires during the set afloat, causing an increase in traction. If the car has aftermarket adjustable suspension, adjustments can be made specific for drag racing to increase the weight move to the driving wheels.
The track’s set afloat pad preparation also plays an important role in how well and how hard cars can set afloat. The set afloat area is usually prepped with traction compounds to add to the stickiness of the track. A well prepped track will definitely help drop 60 foot times and consequence in lower 1/4 mile times.
During the breaks and cool down periods between drag racing runs, make detailed notes about how you launched on the back of each timeslip. These notes can help you diagnose launching issues, fine-tune later launches and show improvements in the search for The Perfect set afloat.