Diesel Truck 2.6 Rules

  1. All general truck rules apply to this class. The Street Diesel (SD) class is designed for full bodied, four wheel drive or two wheel drive pickup trucks.
  2. Weight: 8000 lbs. Maximum, with driver.
  3. Ballast: Ballast is permitted. Hanging weights may not extend more than 60 inches from the centerline of the front axle.
  4. Batteries: The batteries must be securely mounted. They may not be located in the driver compartment.
  5. Body: The body must be an OEM truck body. Trucks with gutterd bed must place a 200 lb. weight no further forward than the rear axle. The body must retain full sheet metal. Metal aftermarket hoods are permitted. Fiberglass is prohibited. The hood must be closed and securely latched while the vehicle is hooked to the sled. The complete OEM firewall and complete OEM floor pan is mandatory.
  6. Brakes: Front 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 System: optional
  9. Credentials: All drivers must have a valid state driver’s license.
  10. Driveline: An OEM transmission and transfer case is mandatory to pull at the 8000 lb. weight. They must have been an option on a one-ton or smaller pickup. Trucks will be allowed to run an open driveline, but must weigh 7700 lbs. and have a drawbar hitch height of 25 inches.
  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. Driveshaft Loops: All trucks must have at least six inch wide u-joint shields around the rear u-joint constructed of at least 1/4-inch steel or 3/8 inch aluminum that will safely contain the u-joint and the end of the rear shaft. All shields must be securely mounted to the vehicle. Any front shaft u-joint that is visible from the side of the truck must be shielded to contain the u-joint and the end of the shaft.
  13. Engine: The engine block must have been available as a factory option on a one-ton or smaller pickup truck.
  14. Exhaust: All vehicles must be equipped to direct exhaust upward. Two 3/8 inch diameter bolts minimum grade 5 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 and the use of PROPANE is also prohibited. All system components MUST be removed from the truck.
  17. Fuel Injection Pump: Maximum “P” series pump allowed. One plunger permitted per cylinder.
  18. Harmonic Balancer: All engines turning 4500 RPM and higher must be equipped with a harmonic balancer or damper meeting SFI Spec 18.1. A shield across the frame under the front of the engine shielding the damper and engine fan area is required.
  19. Hitch: Drawbar hitch is mandatory. The hitch must be a frame mount. Reinforcements must not extend forward of the centerline of the rear axle or to the axle housing itself. Trick hitches are prohibited. Hook point must be no closer than 44” to the centerline of the rear axle. The hitch must be horizontal to the ground and stationary in all directions. Hitch must not exceed a maximum of 25 degree angle from pivot point to hook point. 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.
  20. Rear End: Trucks running a rear end that was an option on a one-ton or smaller pick up will be allowed to pull at the 8000 lb. weight. Rear axle bolts must be covered by a cap or shield. Trucks will be allowed to run an open rear end, but must weigh 7800 lbs. and have a drawbar hitch height of 26 inches.
  21. Steering: The vehicle must retain the full, original OEM steering gear. Additional stabilizers are permitted.
  22. Suspension, Front: The factory suspension configuration must be retained. 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. The final decision rests with the NADM Technical Department.
  23. Suspension, Rear: Rigid or 4-link suspensions are permitted. Air suspension is permitted; the compressor must be disconnected.
  24. Tires: The tires must be DOT street tires. Cut tires are prohibited.
  25. Tow Vehicles: Tow vehicles are prohibited.
  26. Transfer Case: Non-OEM transfer cases are prohibited. It must have been an option on a one-ton or smaller pickup truck.
  27. 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 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 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.
  28. Transmission, Manual: Non-OEM transmissions are prohibited. Aftermarket internal components are permitted. A clutch meeting minimum SFI Spec 1.1 or 1.2 is mandatory on all vehicles. All manual transmissions must be clutch assisted. Sequential shifters are prohibited. All vehicles with engines equipped with a manual transmission must have a flywheel shield labeled as meeting minimum 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.
  29. Turbocharger: The vehicle is limited to a single turbocharger; the inducer bore on the compressor housing may be 2.6”. The inlet will be measured using a 2.65-inch plug or internal calipers. Bushing from any larger turbo size down to a 2.6 turbo is PROHIBITED. A stock map width enhancement (MWE) groove is allowed. No MWE groove will be allowed that has a width greater than 1/4 inch. MWE groove must be inside neck area where intake cover is measured @ 2.6. All provisions allowing air to the wheel other than via the bore and the MWE groove are prohibited. 6.4 liter Powerstroke engines may utilize the factory twin-turbo configuration.
  30. Water Injection: Water injection is prohibited. All system components must be removed from the truck.
  31. Wheelbase: The vehicle must retain the original unaltered factory wheelbase and track width. Front dual-wheel spacers may be used only with accompanying positive-offset dually style wheels.
  32. Kill Switch: Kill switch is required and must be in an easily accessible location..