Downforce operates on the same principle as lift, but in reverse. This effect is referred to as “aerodynamic grip” and is distinct from “mechanical grip”, which is a function of a car’s mass, tires, and suspension. Downforce increases with the square of a car’s speed and requires a certain minimum speed to be significant.
The magnitude of downforce created by wings or spoilers is dependent on the shape, orientation, and speed of the vehicle. A larger surface area creates greater downforce and drag, while a greater angle of attack creates more downforce but also more drag.
The shape of a car’s body is designed to minimize wind resistance. Detailed bodywork directs airflow to downforce-creating elements. The overall shape of a car resembles an airplane wing, typically producing lift, which is counteracted by techniques to create downforce.
Race cars amplify downforce effects by adding a rear diffuser to accelerate air under the car and lessen the car’s wake. Other aerodynamic components, such as splitters and vortex generators, can also improve downforce and reduce drag. Some cars, like the DeltaWing, generate all their downforce through their body shape.
Airfoils, or wings, at the front of a car create downforce to enhance front tire grip and optimize airflow to the rest of the car. These front wings undergo constant modification based on data gathered from each race and are customized for each circuit.
At the rear of the car, the flow of air is affected by multiple components, making the rear wing less aerodynamically efficient than the front. However, the rear wing typically generates more than twice as much downforce as the front to maintain car balance, and often uses multiple elements to increase the amount of downforce created. Like the front wings, these elements can be adjusted during servicing.
Teams have experimented with positioning wings in unconventional locations, partly due to rules aimed at reducing downforce from traditional front and rear wings. Small wings mounted on the rear of sidepods were common in the mid-1990s but were outlawed in 2009.
The 1995 McLaren Mercedes MP4/10 featured a "midwing" mounted on top of the engine cover, a design later adopted by other teams. “X-wings,” high wings mounted on the front of the sidepods, were used by Tyrrell in 1997 and other teams, but were banned due to obstruction during refueling and driver safety concerns. Modern teams often focus on improving the performance of existing wings using flow controllers.
Bernoulli’s principle, body kit, Formula One car, grip (auto racing), ground effect in cars, lift (force).
Simon McBeath, Competition Car Downforce: A Practical Handbook, SAE International, 2000, ISBN 1-85960-662-8. Simon McBeath, Competition Car Aerodynamics, Haynes, 2006. Enrico Benzing, Ali / Wings. Progettazione e applicazione su auto da corsa, Nada, 2012.
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