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1. All tractors will be required to have a 47.1 SFI Spec. roll-over protection.

2. All Limited Pro Stock/Super Farm Tractors are allowed a maximum tire size of 24.5x32.

3. All Limited Pro Stock/Super Farm tractors must utilize an OEM (Ag Chassis) tractor chassis. Component tractors are PROHIBITTED!

4. Only mechanical activated clutches permitted.

5. Must use an OEM Style Cast Head and Block. No Billet or Aluminum. OEM Style stock head for the series of engines used is required, maximum of two (2) valves per cylinder. OPTION: A Re- Cast Head/block may be used but must remain within 1⁄2” of factory dimension specifications for the OEM head. No Billet or Aluminum recast heads/blocks.

6. O.E.M. block cannot be altered in any way externally, except for normal repair or for mounting fuel injection pumps. Internal webbing and water jacket to remain intact with provisions to re-bore the motor block.

7. All Limited Pro Stock/Super Farm Tractors must have a shield between driver and tire to consist of a solid barrier between driver and any part of the rear tires, sufficient to support the weight of the driver. The barrier must be a minimum of 6” inches from the vertical out over the tire configured as the tire.

8. A deflection shield between driver and engine from top of hood to top of torque or transmission housing or clutch housing is required. Deflection shield must go from side shield to side shield. This also provides a flash fire barrier.

9.  Diesel is the only approved fuel – use of ALCOHOL is strictly prohibited in either the fuel or the water injection. Each tractor is subject to both fuel and water sampling at each event. Failure to submit to immediate testing will result in disqualification from the event.

10. No sigma pumps OR MW pumps are permitted. Fuel injection pumps may not be girdled.


1. Limited Pro Stock Tractors will compete at a maximum weight of 8,700 lbs.

2. 540 cubic inch maximum

3. Tractors are allowed a single (1) turbocharger with any manifold modifications necessary to mount the turbo charger.

4. Limited Pro Stock turbocharger, G-Trim Max on Exhaust Side of Turbo (Limited to 4.5” Outlet I.D.”)

5. Manifold pressure may be a single stage only.

6. ‘A’ PUMP: Only one plunger per cylinder and one injector per cylinder are permitted. All ‘A’ pumps must be derived from the German Bosch design. Pumps must maintain stock dimensions.

7. 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.

8. No inner/after coolers allowed. No CO2 or any other means of cooling the air in the piping or manifold. No ice filled or ice cooled devices onboard tractor of any kind. All engine air must enter the inlet of the turbo at ambient air temp & humidity. Inlet air may not be drawn through or across any type of cooling device.


1. Super Farm Tractors will compete at a maximum weight of 9,500 lbs.

2. 640 cubic inch maximum

3. P-pump with 1 plunger per cylinder. Pumps must maintain stock dimensions.

4. Intake will be limited to a Maximum O.D. Size of 3.75” measured at the manifold attachment point with one inlet pipe only.

5. Turbo housing may not be altered to accommodate a smaller foot or base. Such as a T18 with a smaller foot or base welded to it.

6. Exhaust housing bolt pattern shall be no larger than 2.75 x 3.5 inches.


a) Intake housing to be no larger than 3” at the face of the wheel.

b) Compressor wheel tips must protrude into 3” bore.

c) Map width enhancement of .200” Maximum is permitted. Must be in OEM location

d) 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


a) Turbine wheel to be no less than 2.90” in diameter at intersection of turbine wheel face and tip


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

c) All turbine wheel blades protrude 1/8” into 3” bore. All air must exit through the 3” opening.

d) Exhaust housing will be measured at the intersection of turbine wheel face and tip diameter.

9. No waste gates permitted.

10. No variable geometric turbochargers permitted.

8,700 lb. LIMITED PRO STOCK (Mod Turbo)/ 9,500 lb. SUPER FARM

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