Chapter 3 of 6 · 1 min read
Ground Effect & the Floor
The most powerful aerodynamic part of a modern F1 car is the one you cannot see: the floor. Today’s cars are ground-effect cars, using shaped tunnels underneath to generate the bulk of their downforce.
- Venturi tunnels
- Channels under the floor that narrow then widen, accelerating the air flowing beneath the car.
- Low pressure
- Faster-moving air has lower pressure (the Bernoulli principle), so the underside is sucked toward the road.
- Ground effect
- The resulting downforce generated under the car rather than on top of it.
Ground effect is fierce but fussy: it strengthens the closer the floor runs to the road, so teams want to run the car as low as they dare. Run it too low and the airflow under the floor can stall and reconnect over and over, making the car bounce violently on the straights — the phenomenon nicknamed porpoising. There is also a hard limit: a wooden plank under the floor must not wear past a set thickness, proof the car was not run illegally low, and a worn plank means disqualification.
Key takeaways
- The floor is the dominant aerodynamic surface today.
- Venturi tunnels speed up underbody air, dropping pressure and sucking the car down.
- Ground effect makes grip with little drag, so floor gains help everywhere.
- Running too low risks porpoising and illegal plank wear (a disqualification).
- Ground effect was used in the 1970s, banned, then reintroduced for closer racing.