Tractor Pull Guidelines

Modified Stock Rules

Modified Farm STOCK
Revised – 2024

1. Seat Belt Required. (New - Jan. 2024)
2.     All general and safety rules apply to farm stock class.
3.     Maximum tire sizes per weight class are:
5500 & 6000 lb. – 18.4×38
4.     Any cut tires.
5.     Any tractor with a roll cage must wear helmet/seat belt. 
6.     EXHAUST: All exhaust pipes must be straight up with no curves or bends. 

Pro Farm Turbo Rules

Pro Farm Turbo 9,500 and 10,500 lb.
Revised – Dec. 2021

1.     Rules: All General Rules and Safety Rules apply to the Turbo Class unless otherwise specified in the following rules.
2.     Engine: Engine, not to exceed 585 ci, must be of same manufacture as tractor with the same number of cylinders (i.e. an International tractor must have an International engine). Engine must bolt in manufacturer’s intended location.
3.     Intercooler: Only factory equipped intercoolers using engine coolant allowed.
4.     Engine RPM: Engine is not to exceed 3000 RPM while pulling. Tractor must have an ISSpro #01R8906 magnetic pick-up with 14-16 gauge 110v wire attached to 3 prong female plug accessible to the sled. Wire must be one continuous wire outside of frame rails and be visible with no splices.
5.     Charger: 3 inlet 3 exhaust Injector Pump: Any pump up to and including a Bosch P-Pump. 3” inlet 3” exhaust to be measured inside of inlet and exhaust housing. (Revised - Dec. 2021)
6.     Water Injection: Water injection allowed. No pressurized tank systems are allowed.
7.     Maximum tire sizes: 20.8 x 38 any cut tires allowed.
8.     Hitch Opening: Hitch opening size requirements 3 ¾ inch front to back and 3 inch side to side. Note: No loose clevis are to be used. (Revised – Dec. 2017)
9.     Frame Modifications: Frame modifications with approval of tech committee and no component tractors
10.  EXHAUST: All exhaust pipes must be straight up with no curves or bends. (New – Jan. 2020)

Protest Rule: If a tractor is protested, the protest must be made to a member of the Tech Committee by a competitor in same class either before the pull starts or before the tractor in question leaves the pulling track. A protest fee of $500 must be paid by protester, which will go to protestee if the tractor is found to be legal. All points and prize money for that pull will be forfeited, protest fee returned to protester, and protestee barred from pulling at club sanctioned pulls for one year, if tractor found to be illegal or refusal of tear down.

Pro Farm Turbo Safety Rules

Turbo Safety Rules 9,500 & 10,500 lb.
Revised – Jan. 2020

1.     Air Kill: A positive air kill device must be placed on the inlet side of the charger to prevent the ability to build boost. The cable or linkage used to activate this device must be accessible to the sled and driver while in seated position.
2.     Exhaust Pipe: Two 3/8 inch, Grade 5 mm. bolts must be placed at 90 degrees and less than 1 inch apart in the pipe and after the charger outlet.
3.     Hood Line: All Chargers must be under the stock hood or be shielded 360 degrees. If hood is fiberglass charger must be shielded.
4.     Side Shields: If side shields are used they must be made of either 0.060-inch mm thickness aluminum or 0.030-inch mm. thickness steel. If used, shields must cover the entire engine compartment. Side shields must be easily removable.
5.     Dead Man Throttle: Throttle must be spring loaded or otherwise made so that, if released, the engine returns to an idle while running.
6.     Fire Extinguisher: All tractors are to carry a working ABC or Halon type extinguisher that is readily accessible to the driver while in the seated position.
7.     Tip-over Bars: Required as per Safety Rules.
8.     Roll Cage: A roll cage with 5 point harness may be used. ROPS is REQUIRED with quick release seat belt. Must be able to lift one rear wheel when pulled horizontally from top of the ROPS/Cage without damage to the ROPS/Cage.
9.     EXHAUST: All exhaust pipes must be straight up with no curves or bends. (New – Jan. 2020)

Altered Farm Stock Rules

ALTERED FARM STOCK
9,000 — 8 MPH
Revised – Jan. 2026

If no speed board - one horn up to 100 feet. (New - Jan. 2026)

1.     Drivers must be able to safely maintain control of tractor at all times.  Those under 18 years of age must have parental/guardian permission.
2.     No year limit on age of tractor.
3.     Speed limit will be 8 mph.
4.     Tractors must have a stock engine or their factory replacement.  Engines are to remain unchanged in outside appearance.
5.     The Hood, Grill, Frame, (revised - Jan.2024) Transmission, Rear End, and Axel must be for that make and model and must maintain stock appearance and dimension.
6.     All manifolds must be from the same manufacturer and must bolt in stock location without modification.  Manifolds may be altered to fit turbo under hood.  M&W OK.
7.     3000 RPM Maximum. [Engine RPM: Engine is not to exceed 3000 RPM while pulling. Tractor must have an ISSpro #01R8906 magnetic pick-up with 14-16 gauge 110v wire attached to 3 prong female plug accessible to the sled. Wire must be one continuous wire outside of frame rails and be visible with no splices. (new Jan. 2020) ]. The governor lever must come to the governor stop on all injection pumps.
8.     Single Turbo Charger Only.
9.     18.4 x 38 maximum tire size.  Radials allowed.  Top Cut tires allowed.
10.  Wheelie bars are mandatory.  Kill switches/air shut-offs recommended (Revised - Jan. -2024).
11.  Draw bar must not exceed 20 inches in height or be less than 18 inches from the center of the axle to the hooking point. No part of the draw bar may extend rearward beyond the point of hook.  Draw bars must be stationary in all directions.  No clevises.
12.  Total length of tractor is to be a maximum of 13 feet from the center of the rear axle to the furthest point forward, including weights.  Weight brackets may be used. (revised - Jan. 2026)
13.  Any jerking of sled or side stepping clutch will result in disqualification.
14.  Drivers must stay on the seat of the tractor at all times.  Hands must be on the steering wheel, hand clutch, or throttle.  Feet must stay on platform at all times during the pull.
15.  Any tractor or puller found to be unsafe or illegal may be disqualified or barred from hooking. No alcoholic beverages will be permitted during pull.
16.  Any tractor parts falling off (weights, etc.) while hooked to the sled will result in disqualification.
17.  Judge’s or promoter’s decision is final at all times during the pull.
18.  Any tractor with a roll cage must wear helmet/seat belt. (New Jan. 2017)
19.  EXHAUST PIPE: Must have (2) 3/8”, grade 5, bolts through exhaust pipe (must make cross in pipe) as close to turbo as possible. (New – Jan. 2020)
20.  EXHAUST: All exhaust pipes must be straight up with no curves or bends. (New – Jan. 2020)

ALTERED FARM STOCK
10,000 — 12 MPH
Revised – Jan. 2026

If no speed board - one horn up to 100 feet. (New - Jan. 2026)

1.     Drivers must be able to safely maintain control of tractor at all times.  Those under 18 years of age must have parental/guardian permission.
2.     No year limit on age of tractor.
3.     Speed limit will be 12 mph.
4.     Tractors must have a stock engine or their factory replacement.  Engines are to remain unchanged in outside appearance.
5.     The Hood, Grill, Frame, (revised - Jan.2024) Transmission, Rear End, and Axel must be for that make and model and must maintain stock appearance and dimension.
6.     All manifolds must be from the same manufacturer and must bolt in stock location without modification.  Manifolds may be altered to fit turbo under hood.  M&W OK.
7.     3000 RPM Maximum. [Engine RPM: Engine is not to exceed 3000 RPM while pulling. Tractor must have an ISSpro #01R8906 magnetic pick-up with 14-16 gauge 110v wire attached to 3 prong female plug accessible to the sled. Wire must be one continuous wire outside of frame rails and be visible with no splices. (new Jan. 2020) ]. The governor lever must come to the governor stop on all injection pumps.
8.     Single Turbo Charger Only.
9.     18.4 x 38 maximum tire size.  Radials allowed.  Top Cut tires allowed.
10.  Wheelie bars are mandatory.  Kill switches/air shut-offs recommended (Revised - Jan. -2024).
11.  Draw bar must not exceed 20 inches in height or be less than 18 inches from the center of the axle to the hooking point. No part of the draw bar may extend rearward beyond the point of hook.  Draw bars must be stationary in all directions.  No clevises.
12.  Total length of tractor is to be a maximum of 13 feet from the center of the rear axle to the furthest point forward, including weights.  Weight brackets may be used. (revised - Jan. 2026)
13.  Any jerking of sled or side stepping clutch will result in disqualification.
14.  Drivers must stay on the seat of the tractor at all times.  Hands must be on the steering wheel, hand clutch, or throttle.  Feet must stay on platform at all times during the pull.
15.  Any tractor or puller found to be unsafe or illegal may be disqualified or barred from hooking. No alcoholic beverages will be permitted during pull.
16.  Any tractor parts falling off (weights, etc.) while hooked to the sled will result in disqualification.
17.  Judge’s or promoter’s decision is final at all times during the pull.
18.  Any tractor with a roll cage must wear helmet/seat belt. (New Jan. 2017)
19.  EXHAUST PIPE: Must have (2) 3/8”, grade 5, bolts through exhaust pipe (must make cross in pipe) as close to turbo as possible. (New – Jan. 2020)
20.  EXHAUST: All exhaust pipes must be straight up with no curves or bends. (New – Jan. 2020)

AFPA 5-MPH Top Cut (New March 2024).

Rules set until year 2025

If there is no Speed Board Display at the event and you go over the speed limit of 5 MPH. No horn will blow. Disqualified from the announcers stand. Revised - Mar. 2025

  1. Speed limit will be 5 MPH.

  2. 15.5 x 38 maximum tire size. Radials allowed. Top cut or non-cut tires only.

  3. Any year tractor allowed.

  4. Any engine modification/repower allowed. Maximum 6 cylinder. Inline configuration only. Forced induction allowed. Gasoline, LP, or Diesel fuel only.

  5. Must have tractor rear end and sheet metal, aftermarket frame rails and altered wheelbase allowed. Sheet metal and rear end do not have to be like kind.

  6. A fire extinguisher is mandatory on all tractors.

  7. Working kill switch is required on all tractors.

  8. Any tractor turning 3000RPM must have high speed fan or electric fan, dead man throttle, and safety blanket, steel scatter shield 8” wide x 3/8” thick 360 degrees around clutch housing, or SFI approved explosion proof bell housing.

  9. Exhaust: All exhaust pipes must be straight up with no curves or bends. If running a turbo, one of the three following methods of containment MUST be present in the exhaust as close to the turbo as possible. 4 x 3/8” Grade 5 bolts, 2 x 1/2” grade 5 bolts spaced less than 1” apart in the pipe, or a turbo containment ring. All turbos must be shielded 360 degrees. If hood is fiberglass, charger must be shielded.

  10. Operator’s seat must be sturdy. NO flat seats, must be at least a pan style.

  11. Weights, brackets, or any part of the tractor may not extend forward more than 11 feet from the center of the rear axle or rearward past the plane of the rear tires. Front weights must be secured. Rear weights may not be mounted on any part of the 3-point hitch.

  12. Drawbar may be no shorter than 18 inches from the centerline of the rear axle to the point of hook and no higher than 20 inches and stationery in all directions with a hitch opening size requiremens: 3 3/4 inch front to back and 3 inch side to side. No Loose clevis to be used.

  13. Tip-over bars required. Minimum requirements are: Tip=over bars must be attached to drawbar. Pads are to be 5 inches square and 20 inches appart. Pads must be 5 inches behind the plane of rear tire and a maximum of 10 inches above ground. Tip-over bars must support weight of tractor in its heaviest class. Jacking up tractor pads is test of strength and tech committee may perform this test.

  14. The first puller, who will be the test puller in each class, has the option to keep the pull or drop to third position or last, In pull-off, there will be no test puller.

  15. If the puller attempts to stop before the 75-foot mark, the puller will be given one restart.

  16. If the tractor touches the boundary line during the pull, except after 300feet, the tractor will be disqualified.

  17. If any weight or part falls to the ground while hooked to the sled, the tractor is disqualified. If due to internal breakage, a measurement will be taken.

9,500# Hot Farm Tractor

New - Jan. 2026

THE AFPA HOT FARM TRACTOR CLASS WILL FOLLOW SUIT AND ADJUST THE RULES TO COMPLY WITH NTPA’S TURBO UPDATE for 2026 WITH THIS EXCEPTION: 600 CUBE TRACTORS CAN RUN A 3X3.5 AND THE CLASS WEIGHT WILL BE 9500 POUNDS FOR ALL TRACTORS.

  1. NTPA Hot Farm Turbo Rule Amendment - effective 01-29-2026 The WPI and NTPA Executive Board of Directors have approved the following amendment to the Hot Farm turbocharger rules. this rule change came about due to manipulation of the turbocharger MWE groove machined into the air intake portion of the compressor housing. Turbochargers with a MWE groove will not be accepted in the Hot Farm division after the 2026 season.

  2. Turbochargers MWE groove must be located in the neck area of the compressor housing and be no larger than .200 inch where the intake opening is measured at 3-inches. In addition, the MWE groove must measure no larger than .200 inch the entire length of the machined groove. Enforcement may include disassembly for inspection as necessary.

    New Rule: The current 3-inch inlet x 3.5-inch exhaust outlet turbocharger will be accepted with a .200-inch MWE groove as stated through the end of the 2026 season.

    New Rule: Effective immediately, a 3.4-inch inlet x 4-inch exhaust outlet turbocharger utilizing a smooth ait inlet bore will be accepted for the 2026 NTPA season and beyond. Beginning with the 2027 season, this turbocharger will be the only turbocharger accepted in the Hot Farm division.

  3. Turbocharger Pressure Pipe Blanket NEW: Hot Farm division added to rule a) - all applicable rules listed apply to all accepted turbochargers in this division

  4. Turbocharger Intake Cross Intake cross requirement for Hot Farm division will remain as stated for all accepted turbochargers.

  1. 9,500 pounds

  2. 20” hitch height max

  3. Must have at a minimum of a factory R.O.P.S. system capable of supporting the tractor at its heaviest weight class. A 47.1 SFI Spec. roll cage is preferred

  4. Must have steel engine side shield

  5. Must utilize an OEM (Ag Chassis) tractor Chassis. Component tractors are prohibited

  6. Rear weights may not extend more than 6” past rear tires and may not interfere with hooking devices or ability to hook and unhook the tractor from the sled

  7. Tractor must have a stock block or its factory replacement. ReCast Heads allowed (stock dimensions)

  8. Maximum engine displacement of 600 cubic inches. Any tractor is subject to a cubic inch check at any time

  9. Any intake or exhaust manifolds allowed

  10. Diesel fuel only allowed in the “Hot Farm” class

12. Legality of the injector pump by officials is based on the visual inspection of the outside housing and not the inner workings of the injector pump. No billet or Re-Cast Pumps

  1. ‘A’ PUMP: All ‘A’ pumps must be derived from the German Bosch design. Allowed an intercooler

  2. ‘P’ PUMP: No Intercooler

13. All fuel injection Pumps must maintain stock OEM dimensions

14. A single turbocharger ONLY is permitted with the following:

1. 510 CI and under allowed 3×3.5 turbo

2. 511 CI to 600 CI allowed a 3×3” turbo

Intake/Exhaust

  1. Intake manifolds may be non-OEM with a maximum inlet size 3.75” measure on the outside diameter. One inlet pipe only

  2. Exhaust headers allowed

  3. Intake housing to be no larger than 3.11’ at the face of the wheel

  4. Compressor wheel must protrude into the 3” bore

  5. Map with enhancement of .200” Maximum is permitted. Must be in OEM location

  6. All Air flow must go through the turbo intake and map ring, no other air flow will be permitted. IE. Drilled holes around the turbo intake

510 CI AND UNDER

  1. Turbo restriction 3” inlet x 3 1/2” exhaust outlet, no waste gates. Compressor wheel must protrude into the 3” bore. Intake housing to be no larger than three inches at the face of the wheel. No additional openings in compressor housing outside the 3” opening. The exhaust side must be no larger than 3.5” at the face of the wheel and the wheel should protrude the housing 1/8”. MWE groove is allowed a maximum width of .200. MWE groove must be inside neck area where intake covered is measured at 3” and over

  2. Turbine wheel to be no less than 3.0” in diameter at intersection of turbine wheel face and diameter

  3. Turbine housing to be no larger than 3” at intersection of turbine wheel face and tip diameter

  4. All turbine wheel blades must protrude into 3” bore. All air must exit through 3” opening

  5. Tip diameter

  6. No waste gates permitted

  7. No variable geometric turbos permitted

15. No waste gates permitted

16. No variable geometric Turbos permitted

17. No clipping of turbo wheels to allow larger wheels in a smaller housing

18. Engine head must be OEM agriculture-type (re-cast heads allowed, stock dimensions) for that brand engine

19. No overhead cams allowed. Maximum of 2 valves per cylinder.

These rules are only effective for the 2026 pulling season. They will be revisited at the end of the pulling season.

Run What You Brung

New - Jan. 2026

  1. 8,500 LBS

  2. Hitch height: Tractor 20 inches

  3. Cross bolts, if turbo engines

  4. Kill Switch

  5. Fire Extinguisher - STRONGLY RECOMMENDED

  6. Wheelie bars - tractors

Hitch: Tractor & truck pullers hitch opening size requirements: 3 ¾ inch front to back and 3 inch side to side, Note: No loose clevis are to be used (Revised - Dec. 2017)

For info contact: Tony Carnahan: 740-416-8707, John Ohlinger: 304-882-2422, Glen Kennedy: 740-742-2133, Ralph Kelvington: 304-812-7133, Rusty Carnahan: 740-416-1590, Noah Hysell: 740-591-4034, or Dave Wilcox: 740-742-2278.