Officials in the National Muscle Car Association (NMCA) and the National Mustang Racers Association (NMRA) Technical Departments have released updates to its 2019 rules regarding turbocharger modifications.

The NMCA divisions affected include the NMCA VP Racing Fuels Xtreme Pro Mods and the NMCA VP Racing Fuels/Mickey Thompson Street Outlaws. The NMCA Factory Super Cars will also be affected, but not until after the 11th annual NMRA/NMCA All-Star Nationals event at Atlanta Dragway (Commerce, Georgia) on April 4-7, 2019.

Only one NMRA division is affected by the update, the NMRA VP Racing Fuels Street Outlaws.

The updated rules remind competitors that compressor and turbine wheels, blades, hubs, as well as cover or housing modifications are prohibited. Turbos must be run as-produced. Recent incidents, according to the racing organizations, have revealed modifications to original designs that could become a safety hazard.

In related news, the NMRA announced that its ProCharger Modified Street category will now include the 2019 Cobra Jet supercharger combination at 3,500 pounds and require a specific set of supercharger/crankshaft pulley dimensions.

These rule adjustments can be found online at the NMCA website and the NMRA website.