2.5 Diesel Truck Rules

  1. All general truck rules apply to this class.
  2. Weight: 8,000# with driver
  3. Ballast: Ballast is permitted. Hanging front weights are permitted but can’t exceed 60” to the furthest most point of the ballast from the center line of the front axle. Ballast may be added in the bed of the truck. If used, ballast must be securely fastened to the bed. Final decisions rest with the NADM Technical Department.
  4. Batteries: The batteries must be securely mounted. They may not be located in the driver compartment or forward of the radiator core support.
  5. Body: The body must be the OEM truck body. The body must retain full sheet metal. Metal aftermarket hoods are permitted. Fiberglass hoods are permitted with a sheet metal or aluminum skin shield underneath of at least .060” thick. The hood must be closed and securely latched while the vehicle is hooked to the sled. The complete OEM firewall and OEM floor pan is mandatory. A factory installed pickup bed or commercial style aftermarket bed must be installed.
  6. Brakes: Four-wheel hydraulic functional brakes are mandatory.
  7. Chassis: The OEM chassis is mandatory. The engine must be in the OEM location for the body used. The vehicle must retain the full OEM chassis. Wheel tubs, back-half conversions, tube chassis, etc., are prohibited.
  8. Cooling systems: Radiators must be in the stock location and be of at least stock size.
  9. Credentials: All drivers must have a valid state driver’s license.
  10. Driveline: An OEM transmission and transfer case are mandatory. They must have been an option on a one-ton or smaller pickup.
  11. Driver Restraint System: The OEM restraint system is mandatory and must be worn, also a DOT approved helmet and full fire suit and neck brace must be worn.
  12. Engine: The engine block must have been available as a factory option on a one ton or smaller pickup truck. Cubic inch limit of 444 CI. Blocks must circulate coolant freely. No hard filled blocks. Electric water pumps allowed. Electric cooling fans allowed. All other accessories must be powered by factory belting.
  13. Kill Switch: All vehicles must have a working and operating kill switch (Located directly above hitch). If the vehicle is equipped with an electric fuel pump, it is required that the kill switch also kill the fuel pump along with the engine ignition.
  14. Exhaust: All vehicles must be equipped to direct exhaust upward. The exhaust must exit rearward of the driver’s compartment. Stacks exiting through the hood or fender well are prohibited. If the muffler or catalytic converter have been changed from stock, two 3/8 inch diameter, minimum grade 5, bolts must be installed through the exhaust pipe in a cross pattern within one inch of each other as close to the turbo as is practical.
  15. Fire Extinguisher System: A fire extinguisher is mandatory. A fire extinguisher system is permitted.
  16. Fuel: The fuel must be pump #1/#2 diesel only. Soy/Bio-diesel fuel is permitted. Off-road diesel fuel is prohibited. NITROUS OXIDE is prohibited along with other oxygen extenders as well as the use of PROPANE is also prohibited. All system components MUST be removed from the truck.
  17. Fuel Injection Pump: The fuel injection pump is limited to a stock-appearing, OEM engine model-specific pump only. The use of multiple high-pressure common-rail fuel pumps is permitted. Powerstroke engines with a single factory turbo may utilize a second HPOP. Pumps from different years in the same engine model may be interchanged. Cylinder number specific (IE: 6 cylinder pump on a 6 cylinder engine). Ag governors are prohibited. Sigma or 12 cylinder pumps are prohibited.
  18. Fuel System: The OEM fuel tank is mandatory and must be used. Racing fuel cells are prohibited and must be removed from the vehicle.
  19. Harmonic Balancer: All engines turning 4500 RPM and higher must be equipped with a harmonic balancer or damper meeting SFI Spec 18.1.
  20. Hitch: MMTTPA requires a drawbar style hitch. NOTE: NADM requires that all hitches have the ability to accept a receiver-style hitch. Reinforcements must not extend forward of the centerline of the rear axle or to the axle housing itself. Trick hitches are prohibited. The hooking point must be the rear-most point on the vehicle and must be rearward of the stock location of the tailgate. The hitch must be horizontal to the ground and stationary in all directions. Bumpers may be notched or removed. The hitch’s height from the ground may not exceed 26 inches on 4wd units and 30 inches on 2wd units. The hooking point must have a minimum 3.750-inch inside diameter opening for the sled hook. The hooking point will be measured to the center of the clevis loop.
  21. Inter coolers: Factory style or aftermarket air-air coolers are permitted. Water-to-air coolers are prohibited. Any means of cooling the air before the engine, except the air to air cooler is prohibited.
  22. Interior: A complete interior, including dashboard, door panels, headliner, etc., is mandatory. Two matching front seats are mandatory. Aftermarket seats are permitted; they must be fully upholstered. All factory controls (lights, signals, horn, windows, wipers, etc.) must be retained and be operative.
  23. Rear-end: Non-OEM rear-end housings are prohibited. It must have been an option on a one-ton or smaller pick up. Rear axle bolts must be covered by a cap or shield.
  24. Steering: The vehicle must retain the full, original OEM steering gear. The vehicle must retain the original OEM power steering assistance, if it was so equipped. Additional stabilizers are permitted. Non-OEM power assist methods are prohibited.
  25. Street Equipment: Complete headlight and taillight assemblies (all) are mandatory and must be operative. Complete OEM windshield and windows are mandatory. Windows must be operative per factory specifications; that is, they must open and close via OEM electrical or mechanical means.
  26. Suspension, Front: The upper mounting point for strut assemblies must be in the factory location. Adjustable caster/camber pillow ball mounts are permitted. The lower control arm may be strengthened provided factory-mounting points to chassis are maintained. The lower mounting point for the strut assembly may be modified for improved caster or camber. Strut tower braces, lower tie bars, sway bars, and limit straps are permitted. Traction bars and devices are permitted. Final decisions rest with the NADM Technical Department.
  27. Suspension, Rear: An OEM-style suspension is mandatory. Lowering or raising the vehicle height with suspension modifications is permitted. Traction bars and devices are permitted; they must be bolt-on only; welds are permitted for attachment to frame or axle housing. All OEM suspension mounting points must be retained and used. Sway bars, limit straps, and camber kits are permitted. The rear suspension must maintain a minimum compression shock travel of one inch; compression stops must be adjustable. All rear suspensions must use at least one working shock absorber per wheel. Airbag spring assistance is permitted; airbag compressors must be disconnected.
  28. Tires: The tires must be DOT street tires. Cut tires are prohibited. Dual wheels will be permitted on factory equipped trucks only. Trucks utilizing dual rear wheels will be limited to a tire with maximum width of 8’’ of tread per tire.
  29. Tow Vehicles: Tow vehicles are prohibited.
  30. Transfer Case: Non-OEM transfer cases are prohibited. The transfer case must have been an option on a one-ton or smaller pickup truck.
  31. Transmission, Automatic: Non-OEM transmissions are prohibited. Aftermarket torque converters, valve bodies and internal components are permitted. Transmission brakes are prohibited. Any non-OEM floor-mounted automatic transmission shifter must be equipped with a spring-loaded positive reverse lockout device to prevent the shifter from accidentally being put into reverse gear. A functional neutral safety switch is mandatory. All transmission lines must be metallic or high-pressure-type hose. All vehicles with engines running 4500 RPM or more and using an automatic transmission must be equipped with a transmission shield meeting SFI Spec 4.1 and must be labeled accordingly. A blanket-type shield is permitted; it must be appropriately labeled as meeting SFI Spec 4.1 and it must extend from the rear of the block to the front of tail housing with a minimum six inch overlap where it is fastened. All non-blanket type shields must incorporate two (or one, per manufacturer’s instructions) 3/4 inch by 1/8 inch straps that bolt to the shield on each side and pass under the transmission pan unless the transmission pan is labeled as meeting SFI Spec 4.1. All vehicles with engines running 4500 RPM or more and using an automatic transmission must be equipped with a flex plate meeting SFI Spec 29.1 and be covered by a flex plate shield meeting SFI Spec 30.1.
  32. Transmission, Manual: Non-OEM transmissions are prohibited. Aftermarket internal components are permitted. A clutch meeting SFI spec 1.1 or 1.2 is mandatory on all vehicles with engines running 4500 RPM or more. All manual transmissions must be clutch assisted. Sequential shifters are prohibited. All vehicles with engines running 4500 RPM or more and equipped with a manual transmission must have a flywheel shield labeled as meeting SFI spec 6.3 or greater. Applications for which an SFI SPEC flywheel shield is not available may use a properly attached SFI 4.1 or 4.2 blanket that completely covers the bell housing; it must be attached to the block and extend rearward to the transmission with a minimum six inch overlap where it is fastened.
  33. Turbocharger: The vehicle is limited to a single turbocharger. The inducer bore on the compressor housing may be no larger than 2.500”. The inlet will be measured using a 2.550'' plug or internal calipers. Bushing of any larger turbo size down to a 2.500 turbo is PROHIBITED. Inducer bore must be non-removable. Turbo compressor covers must be a true-bore inlet. Stepped/ Tapered covers are prohibited. Clipping/ trimming of the compressor wheel is prohibited. The turbo wheel must measure no larger than 2.500'' in front of and behind the MWE. The turbo may utilize a stock map width enhancement (MWE) groove, but is to be no wider than .250” maximum. No MWE alterations will be allowed. All provisions allowing air to the wheel other than via the bore and the MWE groove are prohibited. Exhaust manifold/ Pedestal bolt pattern shall measure no larger than 3.500" x 2.750" (t-4 flange). Altering of the turbo housing to accommodate a smaller foot or base will not be permitted. 6.4 liter Powerstroke/ 6.7 liter scorpion engines may utilize the factory turbo configuration. The driver will be responsible for making the compressor wheel and bore accessible for Tech Officials to measure bore and inspect the compressor wheel.
  34. Water Injection: Water injection is prohibited. No after-market inner coolers. All system components must be removed from the truck.
  35. Wheelbase: The vehicle must retain the original factory wheelbase and track width.