Class Definitions

Super Farm Tractor   Hot Farm Tractor   Super Stock Tractor
Class Director   Class Director   Class Director
Drivers   Drivers   Drivers
Limited single turbo charger diesel only tractor class. 9300 pounds, 20” drawbar, 640 cubic inch displacement limit, 1 turbo charger 3×3” (sealed after inspection), 24.5 x 32 tires, “p” pump, water injection allowed. No after/inter coolers or overhead cams       Diesel or alcohol powered, multiple turbo chargers. Heavy Super Stock tractors at Regional level will run 20” drawbar with the weight at 8000 for alcohol and 8300 for diesel. Light Super Stock Tractors at RN level only will run component tractors at 6200 lbs. and the agricultural rearend tractors at 6500 lbs. Grand National Open (Alcohol) and Diesel (Diesel fuel only) tractors run with a 20” drawbar and weigh 8000 pounds. The Grand National Light Super Stock class has a mixture of fuels, run at 6200 lbs. and put a a wild show due to the high horsepower to weight ratio.
         
Light Pro Stock Tractor   Mini Modified Tractor   Modified Tractor
Class Director   Class Director   Class Director
Drivers   Drivers   Drivers
Single turbo charger diesel only tractor class. 10,000 pounds, 20” drawbar, 680 cubic inch displacement limit, 1 turbo charger, 24.5 x 32 tires, water injection and/or intercoolers allowed. All rules from Pro Stock class plus 540 cid limit, no component chassis, engine heads must be OEM agricultural-type for brand (no billet), no overhead cams, no inner/after coolers, “p” pump 3000 or 7100 series only (only one plunger per cylinder). 8500 pounds   High power to weight ratio, offers exciting rides. Powered by automotive style or turbine engines. 2050 pounds, 18” drawbar, 18.4×16.1 tires. Turbines limited to NTPA 1800 horsepower rating, 575 cid blown or 650 cid naturally aspirated limits.   The class began as farm tractors with non-tractor engines and grew into fully custom machines with multiple engines and power plant types. All divisions of the Modified class use a maximum of a 20” drawbar and 30.5 x 32 tires.
         
Two Wheel Drive   Light Four Wheel Drive Truck   Four Wheel Drive Truck
Class Director   Class Director   Class Director
Drivers   Drivers   Drivers
Truck body, 6200 pound, 575 cid limit, turbocharged or supercharged engines, alcohol fuel, 18.4 x 16.1 tire, 30” drawbar.       Stock appearing 4×4 truck, 6200 pound, 650 cid limited naturally aspirated engine, 112 inch circumference and 20 inch wide rim tire limit, 26” drawbar