Gurney Flap

A Gurney Flap is a small, vertical tab attached to the back edge of a race car's wing that helps create more downforce to improve the car's grip on the track.

Named after American racing driver and engineer Dan Gurney who invented it in the early 1970s, this simple device is typically made from aluminum or carbon fiber. The flap stands perpendicular to the wing's surface and is usually only about 1-2% of the wing's total width, making it a small but effective modification.

The primary purpose of a Gurney Flap is to increase downforce without adding much drag. Downforce is the aerodynamic force that pushes the car down onto the track, giving the tires more grip. This extra grip helps drivers take corners faster and maintain better control at high speeds.

The flap works by changing how air flows around the wing. It creates a small area of turbulent air behind the wing that increases pressure on top of the wing while reducing pressure underneath. This pressure difference generates additional downforce that helps keep the car planted on the track.

Race teams use Gurney Flaps as a tuning tool to adjust their car's aerodynamic balance. By adding or removing flaps, or changing their size, teams can fine-tune how much downforce the car generates to match different track conditions. However, during races, teams typically can only remove flaps rather than add them due to time constraints.

You'll find Gurney Flaps used across many forms of motorsport, including Formula 1, IndyCar, and sports car racing. They can be attached to rear wings, front wings, and other aerodynamic parts of the car. The flaps are usually held in place with strong adhesive tape, making them relatively easy to install or remove between practice sessions.

Beyond motorsport, Gurney Flaps are also used on aircraft and helicopters where improved aerodynamic performance is needed, showing how this racing innovation has found applications in other fields.