9000# Pro-Field Tractor - Heavy & Light Classes

(rules copied from NWMTPA 2020 Rules)

1. Maximum weight will be 9000lbs. 

2. All weights must be securely fastened to the vehicle. 

3. Weights must not interfere with the sled or the sled chain. 

4. Rear weights can not extend more than three inches behind the rear tires. 

5. Front weights can not extend forward more than 13 feet from the center of the rear axle. 

6. All pulling vehicles running anywhere, whether on the track, in the staging area, or in the pit area, must be attended to within 10’ of the vehicle by an association member, or be disqualified for that class. 

7. All drivers must remain seated while operating their pulling vehicle on the track or will be disqualified (general disqualification rule applies). 

8. All pulling vehicles must have fire extinguishers on board and in working condition. 

9. All drivers must wear a full-faced safety helmet, single layer fire suit, and fire retardant gloves during competition (helmet face shield, head sock and fire resistant shoes are recommended). 

10. All pulling vehicles must be equipped with a dead man throttle to bring the vehicle to idle when released. 

11. All tractors must have a strong and rigid seat that is securely fastened to the tractor. All tip seats must be securely fastened while pulling. 

12. All tractors must have stabilizer bars with skid pads. The stabilizers will extend a minimum of 32 inches behind the center of the rear axle. The stabilizer pads must not be more than 10 inches off the ground. The pad must be a minimum of 5 inches square. A minimum of 20 inches will be allowed between the outer most part of the pads. Stabilizer bars must be able to hold the weight of the tractor. All tractors are required to have bumpers on their stabilizer bars that extend behind the rear wheels. 

13. All tractors must have a wide front axle. 

14. All tractors must be equipped with fenders to provide protection for the drivers from the rear tires. The fenders must be strong enough to support the driver's weight. 

15. All ether bottles (starting aids) must be placed outside of engine compartment.

16. All tractors must have an SFI scatter blanket that covers clutch housing 360 degrees. Safety blankets must be inside of safety tie bars.

17. All tractors with frames not bolted to rear axle must have two extra support bars added to prevent splitting of tractor. Each support bar is mounted to the rear axle housing with at least 4 bolts. Each support bar will extend forward of flywheel area and fasten to the side of the block or main frame with at least two 5/8” bolts.

18. On all pulling vehicles using a roll cage, the driver must wear a full-faced safety helmet and use a four-point safety harness securely fastened to the roll cage. Helmet and safety harness must be worn during competition. 

19. All tractors must have engine side shielding made of steel or aluminum and be 16 gauge or .060 thick. 

20. Diesel tractors must have air kill switches sufficient to stop engine.

21. The kill switch fastener must not be placed over 8 inches from the centerline of the tractor. It can't be higher than 48 inches from the draw bar. The tractor weights must not interfere with operation of the kill switch. 

22. All tractors with inline pumps must have a 3 way fuel shut off system that can be activated from the driver’s seat. 

23. Other than the driver, no other riders are allowed in or on the pulling vehicle at any time, whether on the track, in the staging area, or in the pit area. 

24. All tractors must have front axle skid plates. The skid plates must be mounted inline with each frame rail and extend from the center of the front axle forward (on both sides) equal in strength to frame rail material. Skid plate surface to be a minimum of 4” wide and 12” long with minimum 6” curve when measured from the front most part of rolled edge. The skid plate must be able to support the weight of the front end when checked with a jack. Maximum ground clearance is bottom of front wheel rim not to exceed 4 inches with front tires in normal operating position. (See diagram here) OR Front axle support to be made of 2.00” x .095” chrome moly tubing or 2.00” x .120” mild steel tubing or same material as tractor frame rails. (See diagram here) Front axle support should connect to each frame rail inline and extend toward front of tractor. Front skid/front axle support should have radius to prevent digging into track. Front axle support frame should be strong enough to support front end weight of tractor. Support should have a maximum of 4” ground clearance.

25. Each contestant must furnish a hitching device with a hole at least 3” wide x 3.75” long. It must be bolted tightly or welded to the draw bar. If the hitch breaks, a measure will be taken from that point. Drawbars are to be parallel to the ground, with a minimum of 18 inches from the center of rear axle to the hook point, a maximum height of 20 inches to the top of the draw bar. Drawbars must be stationary in all directions. 

26. Drawbars must be rigid in all directions with no movement allowed. Drawbars must have the pivot pin on the same plane as the hitch point and parallel to the ground within 1.5”, plus or minus, per foot of length. This translates into a legally allowed 10 degrees or less of drawbar angle.

27. No fuel additives such as nitrous oxide will be allowed. 

28. All tractors must be equipped with stock appearing factory block or factory replacement for make and model of tractor being pulled. 

29. All tractors must be equipped with individual working rear brakes.

30. A curved exhaust pipe is not allowed. All exhaust will discharge vertically. Cross bolts 3/8 inch in diameter are to be used in the exhaust system. 

31. With the exception of water and approved lubricant, the use of alcohol or any other substance is prohibited for injection purposes.

32. Maximum wheelbase for all tractors to be 114” measured from the center of the rear axle to the center of front axle. 

33. Maximum tractor length for all tractors will be 13’ from the center of the real axles to the furthest point forward (including weights). All tractors can have a 6” maximum tow loop that may exceed the 13’ limit. 

34. No computers are allowed that controls any mechanical operation of the vehicle. 

35. All tractor classes with an RPM limit must purchase an RPM sending device from the NWMTPA and mount this device to their tractor. The connection/hookup to the remote unit for this device will be mounted at the rear of the tractor next to the air/ignition kill switch. 

36. A 1” diameter light will be placed in proximity to the hook point and sensor to aid in hooking the vehicle to the sled. 

37. All tractors in classes with an RPM limit will have their RPM sending device connected to the remote tachometer as they pull the sled down the track when the remote tachometer is mounted on the sled. 

38. All tractors must provide a clear view from the hitch straight up with a width of 8”, and this area must be free from obstructions. This means that no weights should be placed in an area 8” wide extending upward from the top of the drawbar. 

39. Maximum tire size will be 24.5x32 or 20.8x38. 

40. Maximum cubic inch will be 466 with 1% tolerance for wear. 

41. Maximum rpm will be 3500 

42. 5/8 inch Deck Plates Allowed. 

43. The class is in charge of reading the RPM Box All pro-field tractors must purchase a RPM sending device from the NWMTPA and mount this device to their tractor. The connection/hookup to the remote unit for this device will be mounted at the rear of the tractor next to the air/ignition kill switch. The hookup plug will be the female style end of an electrical cord, with a wire going to each side of the spade terminals, ground pin is not used. 

    • All pro-field tractors will have their RPM sending device connected to the RPM box as they pull the sled down the track when the RPM box is mounted on the sled. 

    • Any RPM violation in excess of tolerance will result in disqualification in that class for that pull only. General disqualification rule applies. Protest & Disqualification rules #16 and #17 as they regard over 50 RPM violations do not apply to the pro-field classes.

    • Tractors that are hooking under a single event membership must still comply with rpm limits set for the class and are still subject to protest and inspection. These tractors will be checked using a hand tachometer. 

44. Engine block, transmission, rear end housings and sheet metal must all be from the same manufacturer. 

45. Only OEM intake and exhaust manifolds are allowed. 

    • After market or homemade headers or intakes are not allowed. 

    • Adapters and spacers are allowed between the factory manifold and the turbo for mounting purposes only. 

46. Maximum two valves per cylinder. 

47. No aluminum, billet or re-cast heads allowed. 

48. VP Spec Fuel Troque or DX must be used. 

49. A pitcock needs to be placed somewhere in the fuel system, so a fuel sample can be taken 

50. VP Water injection systems are allowed. Only Spec water will be allowed. 

51. Tractors caught not using current Spec Fuel and/or Water: 1st offence; No Points or Prize Money for the event that night and a $500 fine that must be paid before that Tractor can pull in that class or any other NWMTPA Class. 2nd Offence; Tractor cannot return for Two (2) years and One (1) day from date of 2nd offence and a $500 fine to be paid before the Tractor can pull in that class or any other NWMTPA Class. 

52. A pitcock needs to be placed somewhere in the water system, so a water sample can be taken 

53. Top 3 finisher Fuel and Water will be pulled at each event after every 4th event. 

54. Gasoline, ether, oxygen, alcohol, nitrous oxide, nitromethane, glycerol, and propane (or any combination thereof) are all illegal fuels for primary or secondary fuels. 

55. One fuel injection pump allowed per tractor with all pumps having a maximum one 13mm barrel and plunger per cylinder. 

    • All “P” series pumps are limited to a maximum 13mm barrel and plunger. No pumps larger than Bosch 3000 series or P7100 series. No Sigma or billet housing pumps allowed. 

    • There will be a $25 protest fee to have any one person’s pump inspected. Violation of the above pump specifications will result in disqualification from that class for 1 year, plus forfeit of all winnings from that pull. 

56. One turbocharger allowed per tractor. Turbo must be the box style charger or a charger meeting the following specifications. 

    • If running a P Pump ONLY the 3”(larger) box turbo is allowed. Must be a Garrett GT4202 or GT4202r (with one of the four manufactured exhaust housings: 1.01, 1.15, 1.28, or 1.42) and run in its stock unaltered form. Push in slugs are allowed in this turbo for tuning purposes but turbo housings can not be altered in any way (reducers/slugs must be of the push-in style). 

    • If running an A Pump a 2.8” box turbo is allowed. Must be a Garrett GT4294 or GT4294R (with one of the four manufactured exhaust housings: 1.01, 1.15, 1.28, or 1.42) and run in its stock unaltered form. Push in slugs are allowed in this turbo for tuning purposes, but turbo housings can not be altered in any way (reducers/slugs must be of the push-in style). Turbo maximum inlet size (excluding reducers/ slugs) is 2.800”-2.804” to allow for manufacturing variances. A factory Map width enhancement groove of .102-.106 is allowed. 

    • Otherwise if running an A pump, any alternate turbo can be used but must meet the following specifications: 

      • A maximum 2.75” inlet size measured at the face of the compressor wheel. 

      • Compressor wheel must protrude 1/8” into the inlet housing. 

      • Factory MAP width enhancement groove of .125 or less allowed. 

      •  No removable slugs or reducers allowed. 

      • Slugs or reducers must be welded in place. 

      •  Compressor wheel must protrude 1/8” into the 2.75” opening. 

      •  No bigger than a 3” exhaust wheel. 

      • No Billet Wheels. 

      •  There will be a $25 protest fee to have any one person’s turbo inspected. 

      • At every pull, the 1st place winner in the 9,000# Pro-Field class will have their turbocharger checked for compliance with the rules either by inspecting the seals, or by actually measuring the turbocharger. 

      • Any violation of the turbo rule will result in loss of points, placing, and prize money in that class for that night. 

      • A second violation of the turbo rule in the same season will cause the tractor and puller to be banned from competing in the division for one year from the date of the second violation.

57. NWMTPA can run maximum allowed Turbo for the Pro-Field Class at the Missouri State Fair. 

58. No type of inter-cooler systems are allowed. 

59. All pro-field tractors must be equipped with at least a 2-bar roll cage. 

    • Two bar cage must consist of at least two hoops, and be constructed of at least 1.5” material. If chromemoly is used, wall thickness is a minimum of 0.093”. If steel is used, wall thickness is a minimum of 0.125”. There should be at least two levels of brace bars between each hoop. 

    • It is strongly recommended that a Limited Pro-Stock spec roll cage be used. 

60. On all tractors using a roll cage, the driver must use a four-point safety harness securely fastened to the roll cage. 

61. No u-bolt style dual hubs allowed. Weld on style plates are highly recommended. 

62. No “shift-on-the-fly” (ie torque amplifiers, powershifts, over/unders etc…) can be used during the run. 

63. All balancers or steel hubs are required to have a retainer to restrict forward movement more than ½ inch to keep balancer from coming off the crank. 

64. To receive points, a contestant must give vehicle number when signing up for the class they are pulling in. 

65. Kill Switches must be Zip Tied. 

66. No Traction Control Devices Allowed. IE(Line Lock, Extra Brake Calipers)