2025 Rule Updates

The following are the rule changes and updates that will go into effect for the 2025 pulling season. All changes have been updated within the 2025 OTTPA Rule Book. It is recommended that all competitors review the 2025 Rule Book. The rule book has had significant organization, layout, and format changes as well as many grammatical changes and clarifications made on rules. Because of this, if you believe that something is not stated correctly, or that it is different from the 2024 rule book and should not be please contact Kyle Petsch at kyle@outlawpulling.com.

General Rules:

Tire Pressure Adjustment Clarification – Rule #9.4.4 – .5

Air pressure in tires and/or air suspensions should be set to approximate settings to be used on the track before the vehicle crosses the scale. If air pressure needs to be changed, it is recommended that a tech official, the class representative, or a person designated by the class rep oversees the change to confirm that the hitch height is not over the maximum for the class.
Anyone who is suspected of changing air pressure in tires or suspension will be subject to having their hitch remeasured by a tech official. If the hitch height is found to be illegal, they will lose points and money for that event.

Pro-Stock 4×4 Truck Rules:

Maximum Wheel Width – Rule #13.5.2

Maximum 12-inch wheel width.

Airbag Front Suspension – Rule #13.5.7

Front airbag suspension is allowed and cannot be controlled from inside the cab.

2.6 Diesel Truck Rules:

Intake and Turbo Blankets – Rule #15.1.4

This is a new rule that was added for safety.
Exhaust manifold and exhaust turbo blankets are required.

3.0 Diesel Truck Rules:

Intake and Turbo Blankets – Rule #14.1.3

This is a new rule that was added for safety.
Exhaust manifold and exhaust turbo blankets are required.

Modified 4×4 Truck Rules:

Class Weight – Rule #16.1.6

MOD 4WD vehicles will compete at a maximum weight of 6,350 lbs.

Windshields Not Required – Rule #16.3.4.d

Windshields are recommended but not required. If you don’t have a windshield, it is recommended that you have your face shield down on your helmet.

Hitch Measuring Process – Rule #16.2.1

When measuring the hitch, light pressure may be applied to a tire that is not touching the ground to have it make contact with the ground. This will allow for a more accurately measured hitch height.

Tractor General Rules:

Adding Material to Ends of Cylinder Heads – Rule #20.7.2

Cylinder head must retain OEM (Length/Width/Height) for engine application.
1. Exception: 1.5 inches can be added to the front and back end of the head for tie-down purposes only.

Turbocharger Checking Procedure for LPS, 540 Light Pro, and LLP classes – Rule #20.6.2

For the LPS, 540 Light Pro, and LLP classes the following will be used to check the legality of the turbos in use:
1. 2-point plug with one inch opening and a 30-degree face will verify compliance.
2. Plug must fit the bore and avoid contact with compressor blades.

NOTE: Measurement devices to make sure turbo is legal can be purchased by contacting the OTTPA Competition Director.

Light Limited Modified Tractor Rules:

Ag Engine Diesel Cubic Inch Limitation – Rule #21.3.7.a

Diesel fuel engine using a 4.1 turbocharger with a maximum of 640 CID.

Turbo Rule Update – Rule #21.3.7.d

Ag or industrial diesel limited to 4.1” smooth bore with maximum 4.5” exhaust wheel. Intake wheel must protrude no more or less than 1/8-inch into housing; exhaust wheel must protrude 1/8” into housing, no map width enhancement (MWE) allowed, exhaust must exit through max 4.5” bore in housing.

Allowed Engine Combinations – V8 & Turbine – Rule #21.3.9.b

One Lycoming T53 L-13 turbine and a naturally aspirated wedge head style automotive engine with a maximum of 370 CID at 6000 lbs.

Modified Tractor Rules:

New Engine Combination – Rule #22.4.13

Three (3) Big Block Ford engines with a maximum 2.350” intake valve in A-460 heads, limited to 60% overdrive with a maximum 8-71 supercharger, 650 cubic inch limit.

Turbine Engine Combination Update – Rule #22.4.16.b

Removed statement about adjustment of horsepower after the pull in Whitewright.

Updated Two Engine with Turbo Combination – Rule #22.4.7

Two (2) automotive type engines with maximum 2 turbos per engine, no Hemi, Pontiac, Oldsmobile, Big Chief or Big Duke style heads, 650 cubic inch limit per engine.
1. Turbos limited to 1 per bank, non-staged, 88mm compressor inducer & 103mm exhaust turbine exducer. Intake and exhaust wheels must protrude 1/8” into housings.
2. EFI is allowed.

3200 RPM Super-Field Tractor Rules:

Rules Locked for 3 Years – Rule #23.1.1

Rules are locked and will be the same for the 2025, 2026 and 2027 pulling seasons.

Light Limited Pro Stock Tractor Rules:

Recast Heads Allowed to Run for Points – Rule #24.4.1

Any cast or manufactured cylinder head will be accepted.

Deck Plates Allowed to Run for Points – Rule #24.3.6

Deck plates are allowed.

Over 48 Lug Tires No Points – Rule #24.2.5

Must use tires with 48 lugs or less to run for points. Tractors utilizing tires with more than 48 lugs can run for purse only.

Limited Pro Stock Tractor Rules:

Clarification of Turbocharger Rule – Rule #26.4

Allow any 4.1 smooth bore turbo with maximum 4.5 exhaust wheel.
Intake and exhaust wheel must protrude 1/8-inch into the housing.
No map width enhancement (MWE) is allowed.
Exhaust must exit through max 4.5” bore in housing.
Intake must be smooth with no slots or grooves to allow extra air.
Compressor wheel must enter bore by 1.8” with a minimum diameter of 4.0 inches.
Refer to rule 20.6.3 “Tractor General: Turbochargers” for inspection process.

Pro Stock Tractor Rules:

Turbocharger Must be Sealed – Rule #28.4.2

Turbo must contain a seal that was installed by Wimer Fuel Injection and Turbo.

Light Super Stock Ag Tractor Rules:

1” Spacer Plate Allowed for 4010 Transmission/Rear End Housings – Rule #30.2.3

John Deere tractors that run 4010 transmission/rear end housings can run a 1″ spacer plate to match length of a 4020 transmission/rearend housing.

Outboard Planetaries only on Tractors From the Factory – Rule #30.2.4

No tractor can run outboard planetaries on tractors that were not offered from the factory with outboard planetaries.

Clarification on Unnecessary Holes Cut or Drilled – Rule #30.2.1

All Light Super Stock tractors must have OEM cast engine, clutch/transmission housing, and rear end housing, axle housings bolted together with no unnecessary holes cut or drilled. No aluminum replacements.