An air restrictor is a device that limits the amount of air that can flow through something, such as a machine or a tool. It is used to control the power, speed, or efficiency of the device by regulating the airflow. Full definition
The rear wing was raised and the Corvettes» 5.5 - liter engines were outfitted with larger intake air restrictors in accordance with the GT regulations. (corvetteracing.com)
GTA (and SprintX) rules allow the Porsche 911 GT3 R a 2 mm larger air restrictor compared to the car in the Pro class. (sportscar365.com)
* Dodge Viper GT3 - R: 20 kg weight reduction (1340 to 1320 kg), 1 mm reduction in air restrictor (39 to 38 mm x2), 4 - liter increase in fuel capacity (103 to 107 liters) (sportscar365.com)