SR DRY CARBON FIBER TURBOFAN AERODISC PRO (for Aluminum FRONT Rims) [PORSCHE 718 GT4 RS]

Four decades ago, Porsche introduced a significant aerodynamic innovation known as the turbofan aerodisc, or wheel fan, which remains a subject of intrigue and misunderstanding. This technology first appeared on the Porsche 917/30, a vehicle that dominated the 1973 Can-Am racing series. Widely regarded as the most powerful road racing car of its era, the 917/30 surpassed its predecessor, the 917/10, in speed, size, and weight. During initial testing at Weissach, the 917/30 generated brake temperatures exceeding 700°C (1,290°F), consuming 2.5 inches of brake material in under 300 miles.

Confronted with brake temperatures surpassing the boiling point of contemporary brake fluid, Porsche engineers faced the challenge of managing extreme heat, particularly with the car's wide wheels—15 inches at the front and 19 inches at the rear. Their solution was a set of meticulously crafted, 20-fin wheel fans, or turbofan aerodiscs. The design was straightforward yet effective: radial blades, affixed to the wheel’s outer face, rotated with the wheel to strike and compress air. This action leveraged centrifugal force to expel hot air from the brake system, enhancing cooling efficiency. As long as the wheels spun at sufficient speed, these simple air pumps continuously evacuated superheated air, mitigating the risk of brake failure and improving overall performance.

These devices are no longer utilized in contemporary racing primarily due to regulatory prohibitions enacted by governing bodies. They were classified as movable aerodynamic devices, which violated rules intended to maintain fairness and safety by restricting components that actively alter airflow during motion. Such bans were implemented across various series, including those under the Fédération Internationale de l'Automobile (FIA) and other motorsport organizations, as the turbofans provided an unintended performance advantage through dynamic air evacuation and potential downforce generation.