Return to Diesel Tech Section.
How Sled Pulling Works
Tractor/Truck Pulling 1o1
Sled pulling is a motorsport in which the goal is to pull a weighted down sled the farthest distance possible in a straight line. The vehicle that pulls the sled the farthest is the winner. Sled pulling is synonomous with tractor or truck pulling, but more commonly used as it does not narrow down what types of vehicles are involved. The sport attracts and accomodates a wide variety of vehicle and engine types.
Truck/Tractor Pulling Rigs
Sled pulling is considered one of the world's most powerful motorsports due to the use of extremely high performance engines, and in some cases, use of multiple engines in a single vehicle. It is not unusual for a Modified (class) tractor to run multiple 1000+ hp engines, and a competition truck to run a 2,000+ hp diesel. 10,000 hp rigs can also be found in the sport. The 5.9L Cummins diesel is a popular application in the sport, though in such extreme engines no single manufacturer holds a clear advantage over another. Anyone with a truck may participate in sled pulling, as there are several classes to categorize participants by their performance levels. Classes are often named by the maximum turbocharger size allowed in that class. For example, the 2.6" class is restricted to trucks with a maximum 2.6 inch turbocharger inducer. There are classes for stock/street legal trucks, heavily modified trucks, and several classes between. 4 wheel drive trucks generally hang weights on the front of the vehicle to improve traction of the front tires.
How Sled Pulling Works
Trucks are hitched to a weight transfer sledge. Drivers spool their turbos before being signaled to start their pull. The sled has wheels in the rear and a sliding weight that rests over these wheels. As the sled travels, the transfer weight travels toward the front of the sled, increasing the friction force of the sled onto the track and making it more difficult for trucks to overcome the force of the sled. Trucks pull until they can no longer overcome the increasing force of the sled and come to a stop. The 300 foot mark is considered a full pull.
Sled Pulling Techniques
While each driver has their own unique approach to sled pulling, there are 2 major technique principles. One technique is to leave the starting line hard and accelerate as quickly as possible before the weight of the sled starts overpowering the vehicle. The principle here is that the momentum of a fast moving truck will keep the sled moving longer. The second technique is the slow and steady approach. Leave the line strong but conservatively and rely on torque and traction to keep the sled moving as the force is increased. One might argue that the best sled pulling technique is a combination of these principles and unique to each vehicle.