2025 Turbo Rules & Enforcement
01/13/2025 – For the 2025 Outlaw Truck and Tractor Pulling Association season the following rules will apply for the turbochargers in the following classes:
Affected Classes:
- Limited Pro Stock Tractor
- 540 Light Pro Stock Tractor
- Light Limited Pro Stock Tractor
New Turbo Checking Procedure:
- 2-point plug with one inch opening and a 30-degree face will verify compliance.
- 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.
2025 Limited Pro Stock Turbocharger – 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.
2025 540 Light Pro Stock Turbocharger – Rule #27.4:
- Any turbo allowed, with 4.5” max exhaust wheel
- Exhaust Wheel must protrude 1/8” into housing
- All exhaust to exit through max 4.5” bore in housing.
- Maximum 5-inch intake housing.
- Refer to rule 20.6.3 “Tractor General: Turbochargers” for inspection process
2025 Light Limited Pro Stock Turbocharger – Rule #24.5
- Any 3×4 smooth bore turbo
- No map width enhancement (MWE) allowed
- Intake and exhaust wheel must protrude into housing 1/8”
- Refer to rule 20.6.3 “Tractor General: Turbochargers” for inspection process