1. Tractor Frame-Chassis
Tractors must be agricultural tractors having chassis, engine, transmission housing, differential housing, transmission, hood, and grille of one manufacturer. OEM cylinder head must be for series engine used-No re-cast, No aluminum, No overhead cams allowed. Engine, clutch, transmission, and differential housings, must be bolted together as one unit. All bolts connecting all housings must be in their stock location-OEM length & location from rear end housing to front of engine. No component powertrains. All tractors must have wide front end configuration. No hood alterations allowed, except by approval. All exhaust must discharge upwards with a minimum pipe length of 18" from the hood line. No rain caps. Exhaust pipe must be cross-bolted with two 5/16" bolts in the horizontal pipe within 2"of exhaust wheel and two 3/8" bolts in the vertical pipe.. The frame and weights must not extend any further than 13 feet from center of rear axle to further most point - excluding tow hook. The wheelbase must not exceed 114". Hitch height shall be 20". Hitch length shall be 18" minimum, from center of axle to hook point. Drawbar must be rigid in all directions - No movement allowed while pulling. HITCH HOLE TO BE 3.75 x 3.0". Drawbar must be within 10 degrees of parallel to the ground. Hitch must be horizontal - Not vertical. All hitch components must be steel - No cast components. Maximum tire size 24.5" x 32" - No radials. Radial tires are allowed for all other tire sizes. Double cut tires are allowed.
2.Engine
Engine size maximum of 466 cubic inches. OEM fuel only - Diesel pump fuel, gasoline, propane - No accelerants. Water injection permitted - No accelerants or alcohol permitted. Injection pump to be stock injection pump or one "A" type (German Bosch only with one plunger per cylinder) = one injector per cylinder. The "A" or stock pump to be the only source of fuel - No "P" pumps allowed. No billet pumps or housings allowed. Tractor must have 3 way fuel dump valve. Tractor allowed one turbocharger and any manifold modifications necessary to mount the turbocharger. Manifold pressure to be single stage only. Carburaters are not to exceed 850 CFM. No fuel injection allowed for gasoline engines. Home made engine adaptor plates are not allowed. Turbocharger must be under hood. Hood may be modified to accept the turbocharger. The maximum size of the turbocharger is not to exceed 3" intake and 4" exhaust. Turbocharger must be equivalent to HX60 series or S-4 series. Map width enhancement grooves allowed. Compressor wheel must enter into the compressor housing. If a tech official finds a pullers turbocharger to be illegal that puller has the option to put a legal turbocharger on or make necessary changes to deem it a legal turbocharger. Only after the tech official has re-inspected the turbo can the puller be eligible for that event. Otherwise the puller is ineligible for that event. If you are caught for a second time with an illegal turbo by a tech official, you are kicked out of the class for 1 year and 10 days. The use of torque converters, and automatic shifts are permitted. All clutch components and flywheels are to be steel or aluminum. Intercoolers are legal for diesel powered tractors but are not allowed on gasoline powered tractors.
3.Safety rules
Tractors must have working air shutoff and deadman throttle. The throttle must have at least 2 springs. The air shutoff cable must activate the air shutoff to the engine and must be positive-type enclosed cable with a minimum 2" diameter solid ring - 1/8" cross section thickness attached to it. Air shutoff must also be able to be operated manually by the operator from the seat of the tractor. Gasoline and propane powered tractors must have a shutoff switch which shuts off the spark and stops the electric fuel pump. Stabilizer bars are required and are to be a minimum of 32" rearward from the center of rear axle. Pads on the bottom of bars to be a minimum of 5 in. sq. and a maximum of 10" off the ground. Outside to outside width to pads to be a minimum of 20". Minimum of 12" high bumper bars required - Top to be fastened to stabilizer bar framing. Do not connect hitch to stabilizer bars. Stabilizer bars must support the weight of tractor. Skid bars are required on front of tractor. Tractors must have a shield that consists of a solid barrier between the driver and any part of the rear tires. The barrier must be able to support the weight of the driver and must extend a minimum of 6" horizontally at the top, and be a minimum of 6" wide at the top. Harmonic balancer must be shielded to contain the balancer within the vehicle. A fire extinguisher is required within reach of driver. Driver must wear a helmet with a Snell 85 rating. Fire suits mandatory. This includes pants and jacket. 5 point safety harness is mandatory and must be worn. Seats must be stationary in all directions - No springs, and have a minimum 6" high back and 4" side rails. Tractors must have approved clutch/transmission safety blanket and engine shields. Side shield material to be minimum .060" thickness. Six strap blankets only - No three strap blankets. Roll cages are mandatory. No roll bars will be accepted. 4.The weight class is 7700 lbs.