Diesel Truck 2.6 Smooth Bore Rules

Class Representatives: Corey Peck, Randy Williams

  1. Maximum weight 8000 lbs.
  2. OEM Chassis is mandatory. The vehicle must retain the full OEM chassis. Wheel tubs, back half conversions, and tube chassis are prohibited. Must retain factory OEM wheelbase for make and model of body, not to exceed 158 inches.
  3. The body must be OEM truck body including the full bed floor. No flatbeds permitted. The body must retain the full sheet metal. After market hoods permitted. The hood must be closed and securely latched when hooked to sled.
  4. Complete engine must have stock appearance except where otherwise noted in these rules. Maximum engine size will be 460 ci. Engine must be in OEM location for the body to be used. Engine must have a 3/8 diameter cable surrounding the engine block. Cable is to be positioned between #1 and #2 cylinders and is to pass through manifolds. Cable will have 4-6 inches of slack. Two cable clamps at cable splice are required.
  5. Cylinder head must be OEM or OEM replica for brand of engine. Outside of cylinder head must measure factory width and length. No billet heads of any material. Head must retain factory OEM valve angle. No deck plates permitted.
  6. Hook point to be no closer than 44 of centerline of rear axle. Maximum hitch height of 24 with a minimum of 3.75x3 opening. Hitch must be stationary in all directions. Hitch must be frame mounted. The use of Reese style hitches is prohibited. Hitch must not exceed 25 degree angle from pivot point to hook point. No hitch supports or adjusters fastened to rear axle housing shall be above center point of rear axle. Pivot pin of drawbar can be no further forward than the centerline of rear axle.
  7. Turbo is limited to 2.6 inducer bore. Bore must be smooth. No MAP Width Enhancement groove (MWE) allowed. Compressor wheel must protrude into 2.6 bore for 1/8. Bore will be checked with a 2.605 turbo plug. Plug must not be able to enter inducer bore and contact wheel.
  8. Turbo is limited to 2.6 inducer bore. Bore must be smooth. No MAP Width Enhancement groove (MWE) allowed. Compressor wheel must protrude into 1. 2.6 bore for 1/8. Bore will be checked with a 2.605 turbo plug. Plug must not be able to enter inducer bore and contact wheel.
  9. All vehicles must be equipped with upward pointing exhaust located either directly behind cab or out of truck hood. Two 3/8 diameter bolts must be placed through the exhaust pipe in a cross pattern within one inch of each other and within 12 inches of turbo.
  10. Front hanging weights are allowed, not to exceed 60 inches forward from the centerline of front axle. Ballast may be added in the bed of truck but must be securely fastened.
  11. All trucks must have at least six inch wide u-joint shield around the rear u-joint constructed of at least 5/16 inch steel or 3/8 aluminum that will safely contain the u-joint and the end of the driveshaft. All shields must be securely mounted to vehicle. Any front shaft u-joints that can be visibly seen from side of truck must be shielded to contain the u-joint and the end of the driveshaft.
  12. A fire extinguisher system is required. 2.5# fire extinguisher must be securely mounted within reach of driver. A complete OEM firewall is required.
  13. All drivers must have valid driver license and full SFI fire suit including helmet, neck brace, fire gloves, fire shoes or leather boots. Seatbelt/restrain must be worn.
  14. The complete OEM floor pan is mandatory. Vehicle must maintain a complete firewall. Additional gauges and pillar pods are permitted.
  15. Hand throttles permitted. Diesel fuel only. No propane or N02 or any other oxygen enhancers allowed.
  16. Maximum of one P pump up to P7100 allowed. 13MM plunger limit. Ag governors permitted. The use of multiple high pressure common rail fuel pumps is legal.
  17. OEM rear and front ends required. Must have come factory in a one ton or smaller vehicle.
  18. Axle shield are required. Shield to be .060 thickness steel or aluminum. A hole may be cut in one shield to allow operation of hub lock.
  19. Safety switch (rain cap or guillotine) must shut off air to diesel engines. Switch will be securely mounted to back of vehicle. A 2 inch or bigger solid ring must be attached to end of switch. Ring must be zip tied to switch bracket. Switch must also be able to be activated in cab while driver is secured in vehicle.
  20. Hydraulic steering permitted.
  21. Suspension (Rear) - The upper mounting point for strut assembly must be in factory location. Adjustable caster/camber pillow ball mounts are permitted. The lower control arm may be strengthened provided the factory mounting points are maintained. Strut tower braces, lower tie bars, sway bars, and limit straps are permitted. Traction bars and devices are permitted. Raising or lowering of vehicle height with suspension modifications is permitted but must be bolt on only. Welds permitted for attachment to frame and axle only. Blocked suspension permitted. No air bags. Rear suspension may be made solid.
  22. Must have 3 way dump valve. Must be able to be pulled from drivers seat.
  23. Tires must be DOT approved with maximum size of 35x12.50. No studded tires or tire chains. No alterations to tires permitted. No bar or terra tires.
  24. Dual wheels are prohibited.
  25. OEM transmission and transfer case must be used. Must have come factory in one ton or smaller vehicle.
  26. Non-OEM transmissions prohibited. Aftermarket torque convertors, valve bodies, and internal components are permitted.
  27. SFI bell housing and/or SFI blow proof bell housing or SFI blanket type shield must be used.
  28. Water injection is prohibited.
  29. Air to Air intercooler only. No cooling device allowed for intercooler. No ice boxes.