2017 2.5/2.6 Smoothbore Truck Rules
Credentials: All drivers must have a valid driver’s license. Vehicle will be allowed to be hauled to the pull. All trucks must be a 1 ton or smaller chassis.
Weight: 8500 pounds Maximum, with driver.
Engine: The engine is limited to a stock appearing, OEM compressing engine, available from the factory in a one ton or smaller truck. Cubic inch limit of 444ci. Blocks must circulate coolant frequently. Engines will be allowed to cross manufacturer’s lines (ex: a Ford may run a Cummins engine). Water pumps may be electric or factory. All factory belt driven accessories, excluding air conditioner compressor must be retained and powered via the crankshaft by a standard serpentine or v belt or belts. Electric cooling fans are permitted. No hard filled blocks/heads. No aftermarket intake manifolds, side draft/runner style intakes not permitted.
Body: The vehicle must retain the original unaltered factory wheelbase. The body must be an OEM truck body, including the full bed floor. The body and truck bed must retain full factory 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. The engine must be in the OEM location for the body being used. Front bumpers are mandatory; Ranch hand style and others are permitted. Rear Bumpers mandatory; Rear roll pans are allowed.
Fuel: The fuel must be pump #1 or #2 diesel only. Soy/Bio-diesel fuel is permitted. Off road diesel fuel is prohibited.
Fuel System: The OEM tank is mandatory and must be used. Racing fuel cells are prohibited and must be removed from the vehicle.
Intercoolers: Factory style or aftermarket air to air replacement only in the stock location. Air to water intercoolers are prohibited.
Exhaust: Strongly encourage all vehicles to have the exhaust exit upwards. Hood stacks are permitted. Trucks with excessive smoke must have a 90 degree turn up attached to the tailpipe. Final decisions rest with the technical department.
Intercooler: Factory style or aftermarket air to air replacement only in stock location. Water to air coolers are prohibited.
Cooling Systems: Radiators must be in the stock location and must be of at least stock size.
Ballast: Ballast is permitted. Hanging weights may not extend more than 60 inches from the centerline of the front axle. Weight boxes are prohibited. Weights and brackets must be removable by hand. No Ballast/added weight in the cab area. All added weight must be secured in bed of truck or front mount. Truck will be disqualified if any weights or ballast falls off during the pull. Final decisions rest with the technical department.
Batteries: The batteries must be securely mounted. They may not be located in the driver compartment or forward of the radiator core support.
Brakes: Four-wheel fully operational OEM hydraulic brakes are mandatory.
Driveshaft Loops: All trucks running for points must have a minimum of six-inch wide u-joint shields around the rear u-joint. Must be 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. Shields around all the u-joints is encouraged.
Power Adders: NITROUS OXIDE is prohibited along with other oxygen extenders and the use of PROPANE is also prohibited. Water Injection is prohibited. All system components MUST be removed.
Fuel Injection Pump: The fuel injection pump is limited to a stock-appearing, OEM engine make-specific pump only. Dual high-pressure common-rail fuel pumps or HPOPs are permitted.
Throttle: OEM style foot throttle only with two springs on the fuel injection pump. No Hand Throttles.
Interior: A complete interior, including dashboard, door panels, headliner, etc., is mandatory. Two matching OEM style front seats are mandatory. Must have full back and head rests on seats. All factory controls (lights, signals, horn, windows, wipers, etc.) must be retained and operative.
Hitch: The hitch must be a receiver-style hitch; reinforcements are permitted. Any hitch attachments /bracing must be from frame down not from axle up. Reinforcements must not extend forward of the centerline of the rear axle. 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. Hitch must be a minimum of 44” measured form the centerline of the rear axle to the hooking point. 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. 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 rear of the opening in the clevis/hook. Hooking point (i.e. where the hook drops) must be parallel to the ground. Final decision of legality of all hitches resides with the head tech official (see diagram below).
Rear End: Non-OEM rear-end housings are prohibited. The rear end must have been an option on a 1-ton or smaller truck.
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.
Street Equipment: Complete headlight and taillight assemblies (all) are mandatory and must be operative in OEM locations. 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.
Rear suspension: May be solid, but stops must be removable. Rear suspension must retain OEM configuration. Traction bars are allowed.
Front Suspension: The factory suspension configuration must be retained. Traction bars and devices are permitted.
Tires: The tires must be DOT street tires. Cut tires are prohibited. Rear Dual Tires permitted with OEM appropriate bed. Max ground contact patch of 18” Per Side for Trucks running dual wheels. Duals on rear must run matching dually negative offset wheel on front.
Transfer Case: Non-OEM transfer cases are prohibited. It must have been an option on a one-ton or smaller pick-up truck.
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 a Minimum SFI Spec 29.1 and be covered by a flex plate shield meeting SFI Spec 30.1
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 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 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.
Turbocharger: For the 2017 season the vehicle is limited to a single turbo with a compressor inducer of 2.5” or a 2.6” smoothbore turbo as specified below. Competitors must make provisions at tech officials' request to allow complete inspection of the compressor wheel and housing. Failure to comply with the request will result in disqualification until the turbo is re-inspected.
· The 2.5 turbo compressor cover inducer bore is limited to 2.50” diameter and will be checked with a 2.530” plug.
· The 2.6 smoothbore is limited to a 2.6” inducer bore with no MWE provisions that allow additional airflow to the wheel and will be checked with a 2.630” plug.