PRO MODIFIED DIESEL 4x4 TRUCKS –8000 lb.
The Pro Modified Diesel category is designed for full-bodied street or track trucks. Weight is with driver.
1. The body must be the OEM truck body. Fiberglass body parts are prohibited. The OEM firewall and OEM floor pan, front to rear, is mandatory. Complete OEM windshield and windows are mandatory. Functional back-up lights are mandatory. Batteries must be securely mounted; they many not be located in the driver compartment.
2. An OEM chassis with complete OEM floor pan and firewall is mandatory. Wheel tubs, back-half conversions, tube chassis etc. are prohibited. The engine must be in the OEM location for the body used. The vehicle must retain the full factory frame.
3. All engines are to be shielded with heavy belting or 0.60 steel. e.g. Steel inner fenders or rubber belting covering everything above the frame to the deck of the motor.
4. The vehicle must have an OEM wheelbase and track width.
5. Front weight is permitted. Hanging weights may not extend more than 60 inches from the centerline of the front axle. They must be securely mounted.
6. An OEM Style Front suspension is mandatory:
(i) 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 lower braces, lower tie bars, sway bars and limit straps are permitted. Traction bars and devices are permitted.
(ii) All locking hubs must be covered with shields made with a minimum of 0.60 steel.
7. An OEM -style rear suspension is mandatory.
(i) Traction bars and devices are permitted. They must be bolt on only; welds are permitted for attachment to the frame or axle housing.
(ii) Control arms may be strengthened or replaced, provided all original mounting points are retained.
(iii) Strut tower braces, lower tie bars, sway bars, limit straps and camber kits are permitted
(iv) Blocking is permitted.
8. Working brakes are mandatory on all four wheels.
9. The hooking point must be the rear-most point on the vehicle.
10. The hitch must be horizontal to the ground and stationary in all directions hooked to the frame no further ahead than t he center of the rear axle.
11. The hitch’s height from the ground may not exceed 26 inches.
12. The hooking point must have a minimum 3.00 inch inside diameter opening for the sled hook.
13. OEM transmission and transfer case is mandatory. It must have been an option on a one-ton or smaller pick up.
14. Vehicle must have at least 3 round metal hoops shielding drive shafts.
(i) 360 Degree hoop must be a minimum of 3/8 inch aluminum or 5/16 steel ¾ inch wide and not more than 2 inches from the shaft in any direction.
(ii) End loops must be placed no further than 6 inches from the universal joints with third loop in center of shaft.
(iii) May use solid tube (3/8 aluminum or 5/16 steel) to meet above requirements.
(i) Non OEM manual transmissions are prohibited.
(ii) All transmissions must be clutch assisted. Sequential shifters are prohibited.
(iii) Non OEM Automatic transmissions are prohibited. Aftermarket torque converters, valve bodies and internal components are permitted.
(iv) Transmission brakes are prohibited.
(v) 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.
(vi) A functional neutral safety switch is mandatory.
16. Tires must be stamped DOT approved with a maximum height of 35 inches and mounted on rims no wider than 14 inches.
Engine: Max. R.P.M. 4500 no load
17. The engine is restricted to a single 6 cylinder or 8 cylinder compression ignition engine.
a) Maximum displacement of 7.6 lt (466 cu.in) all vehicles must have an OEM style engine that came in a 1 Ton pickup or less (conversions are allowed)
b) All engines must be chained down on torque side with a min. of a 3/8” chain grade 70.
c) Balancers must be SFI Approved or be contained with at least one 2 inch by ¼ inch steel bar across the front of the balancer anchored to the engine.
d) All engines must OEM heads and maximum P-pump.
18. All vehicles must be equipped to direct exhaust straight up (no curve outs) either in the box or out of the hood. All hood stacks must be at least 12 inches over the sheet metal. Two Grade 5-(3/8 inch diameter) bolts must be placed in a cross pattern within one inch of each other as close to the final turbo as is practical.
19. Fuel must be pump #1/#2 diesel only. Soy/Biodiesel fuel is permitted. No diesel fuel may enter the Cab.
20. Nitrous oxide is prohibited. All oxygen extenders are prohibited. System components must be removed from the truck.
21. Propane is prohibited. System components must be removed from the truck.
22. Water injection is permitted. Alcohol, methanol and all other flammables are prohibited. No dry ice. Commercially available pump lube is allowed.
23. Turbochargers are limited to dual stage compounding turbos. Atmospheric (final) turbo is limited to a 3-inch inducer bore measured with a 3.05 inch slug. Single turbos are unlimited in size.
ALL BLANKET FASTENERS MUST BE GRADE 8 BOLTS.
1. All vehicles must have a properly attached SF1 4.1 or 4.2 blanket that completely covers the bell housing. It must be attached to the black and extend rearward to the transmission.
a) A clutch (including a flywheel) meeting minimum SF1 Spec 1.1 or 1.2 is mandatory on all vehicles.
b) All transmissions must be clutch assisted. Sequential shifters are prohibited.
2. Automatic Transmission:
a) All vehicles must be equipped with a blanket-type shield meeting SF1 Spec 4.1 and extending from the rear of the block to front of tail housing.
b) All vehicles must be equipped with a flex plate meeting SF1 Spec 29.1
c) All transmission lines must be metallic or high-pressure type hose.
3. A sled- and driver- operated emergency air shut off is mandatory. The sled cable must terminate into a two-inch diameter steel ring.
4. All trucks must be equipped with a driver operated fuel shutoff capable of blocking fuel flow to the injection pump. e.g. inline three-way dump valve or fuel start/stop valve.
5. A fire extinguisher is mandatory. It must be securely mounted behind the driver’s seat.
6. All drivers must wear a fire suit meeting a minimum of SF1 3.2 A/1 and wear leather steel toe boots.
7. All drivers must have a valid driver’s license.
8. The OEM restraint system is mandatory and must be worn.
9. The driver must wear a helmet meeting DOT approval.
10. Driver’s window must remain down during pulling.
11. No vehicle is to be left unoccupied while running at any time.