5900 Pro-Field Tractor Rules

  1. 5900 lb. turbo and 5900 lb. naturally aspirated tractors will pull in the same class.
  2. Any gasoline tractors may run one 4-barrel carburetor; will allow gas turbocharged motors with 361 cubic inch or less to run with no RPM limit. Must use SFI approved clutch.
  3. Tractors will be equipped with a steel flywheel and pressure plate. Positively no gray cast metal allowed in any flywheel or clutch component.
  4. Tractors will be equipped with a SFI SPEC 4.2 bell housing blanket. Any exposed automatic type transmission must be covered by scatter shield.
  5. Sheet metal needs to be in the family of the tractor. Any ag motor with like brand ag rear end.
  6. Primary fuel shall be diesel or pump gas, no alcohol. No electronic controlled fuel injection allowed on gasoline or diesel engine.  No throttle base injection systems.
  7. No nitrous oxide or propane injection system allowed.
  8. Diesel tractors are allowed to run a P pump and gasoline tractors are allowed one 4 barrel carburetor.
  9. Diesel tractors may be converted to gasoline fuel system.
  10. Tractors can pull in higher weight classes, but must comply with all safety rules for that class.
  11. Maximum tire size 18.4x38
  12. Naturally aspirated, maximum of 650 cubic inch Turbo tractors shall have a 360 cubic inch limit.
  13. Diesel tractors equipped with turbo or supercharger shall comply with the following additional rules:
    1. 3000 RPM limit. Tractors shall have operative, factory-equipped governors which will be checked by: visual retarding movement of the throttle linkage from governor case to carburetor; and audible acceleration when clutch is engaged while holding brakes on with tractor in high gear. Tractor shall be equipped with tack cable with one magnet (female connection from tractor) to hook to sled. Verification and consequences, for excessive RPM, shall be the same as Hot Stock classes.
    2. Water & alcohol mix injection into intake allowed.