Ground Effect

Ground effect is an aerodynamic technique used in racing cars to create downforce by designing the underbody to generate low air pressure beneath the car, which effectively sucks the vehicle toward the track surface.

Imagine holding a piece of paper and blowing across the top of it—the paper lifts up because the fast-moving air creates lower pressure above it. Ground effect works in reverse for race cars. By carefully shaping the car's underbody, engineers make air flow faster underneath the car than above it, creating lower pressure below and higher pressure above. This pressure difference pushes the car down onto the track, giving it more grip without adding physical weight.

The magic happens through specially designed channels called venturi tunnels built into the car's floor. These tunnels start wide at the front and gradually narrow as they move toward the back of the car. When air enters these tunnels, it speeds up as the space gets tighter—similar to how water flows faster when you partially cover a garden hose with your thumb. This acceleration of air reduces pressure underneath the car based on a physics principle discovered by scientist Daniel Bernoulli.

The beauty of ground effect aerodynamics is that it produces enormous amounts of downforce with relatively little drag compared to wings and other external aerodynamic devices. This means race cars can take corners much faster while still maintaining good straight-line speed. The closer the car sits to the ground, the stronger this effect becomes, which is why racing teams work hard to keep their cars as low as possible.

Ground effect became famous in Formula 1 during the late 1970s when the Lotus 79 dominated the championship. That car featured sculpted underbody surfaces and flexible side skirts that sealed the gap between the car and track, maximizing the low-pressure zone underneath. The advantage was so significant that other teams quickly copied the concept.

However, ground effect was eventually banned from Formula 1 in the early 1980s due to safety concerns. Cars were becoming dangerously fast through corners, and if the aerodynamic seal was suddenly broken—by hitting a bump or losing a side skirt—the car could lose grip instantly and crash. Formula 1 then relied primarily on wings and other devices for downforce for several decades.

The concept made a grand return to Formula 1 in 2022 with new technical regulations specifically designed to bring back underbody aerodynamics. Modern ground effect cars feature large venturi tunnels along each side of the floor and massive diffusers at the rear. The goal was to reduce the turbulent air created by cars, allowing them to follow each other more closely and improve overtaking opportunities during races.

One challenge with ground effect is a phenomenon called porpoising, where the car bounces up and down rapidly at high speeds. This happens when the car gets sucked too close to the ground, stalling the airflow, which causes the car to rise, then the effect kicks in again, creating a bouncing motion. Teams must carefully balance maximum downforce with controlling this unwanted behavior to keep drivers comfortable and the car stable.