Late Model EFI Rules

Last Updated 9/12/18 – Changes Marked in Yellow

Please also read the ORP General Rules which apply to all races conducted at Ozark.


  • ANY Engine with EFI
  • Exhaust – Mufflers required on all combinations except turbos. Exhaust exiting ahead of
    front tires allowed, but must not affect timing or staging beams. No Zoomies.
  • Engine diaper or NHRA accepted belly pan for oil containment required.


  • N2O – Single Stage Maximum
  • Blower- 8-71 Maximum
  • ProCharger – F1X Maximum
  • Single Turbo – 88mm Maximum
  • Twin Turbo – 67mm Maximum


  1. No Back Half Chassis, No Full Tube Chassis.
  2. Cars must maintain the factory frame. Frame rails must be located in factory position.
  3. Chassis bracing and reinforcing is permitted.
  4. Ladder Bars permitted.
  5. Factory four links are acceptable. Aftermarket four links are illegal!
  6. Minor frame notching will be allowed.
  7. Bolt on front K member allowed.
  8. Front frame rails must be in original OEM location.
  9. Front suspension components may be replaced with after-market bolt-on parts.


  1. Fiberglass hoods, bumpers and deck lids will be the only fiberglass body parts allowed.
  2. Lexan windows are legal


  1. Drag Radial Tire labeled 275/60R15 or smaller.
  2. 28×10.5 Pro Bracket Radial.
  3. 10.5×28.5 slick or smaller – No W’s.


  1. 3000 lb. minimum weight for all combinations
  2. Engine Transplants OK
  3. Cars must have factory interior. Racing seats allowed. Rear seat may be removed.
  4. Cars must have WORKING headlights and tail lights.
  5. Cars must have coolant overflow tank and secured battery mounts mandatory.
  6. Rules subject to review at anytime. Competitors will have a 30 day compliance period should there be any new rules.
  7. No tow vehicles. Racers must drive to the staging lanes from their trailer and drive back to their trailer after their pass.
  8. Cars will run on a .400 pro tree, for an 1/8th mile.
  9. All cars must be able to pass track’s tech inspection – NO EXCEPTIONS.
  10. To maintain the “Spirit of the class” any vehicle to enter the class must be true to the intent and nature of the class. For example, You may not enter your Tow Vehicle, Honda Prius, Smart Car etc. in this class to maintain points if the race car is broke. Any “Fill-In” or “Cross-Over” car that does not typically race this class that wishes to participate, must first meet class rules and must be cleared by the race director before entering the class.

Weight Rule

  • Cars racing in a class with weight restrictions must weigh each pass in qualifying and eliminations. Failure to weigh is a disqualification for that round. There is a zero tolerance policy on weights, you must weigh at least your minimum class weight or more.
  • If the winning car does not make weight and the red-light car does make weight, then the red-light car will be the winner.
  • Any questionable situations in regards to weighing process will be resolved by the Race Director and will be final.