Timelines · Formula 1 · 3 of 7
The whole floor became a wing — downforce with almost no drag, hidden underneath.
1978·Ford-Cosworth DFV 3.0 L V8·~475 hp·1978 Drivers’ (Andretti) + Constructors’ titles, 6 wins·roughly double a winged car of 1977
· THE STORY
After wings, the next trick was hiding the aerodynamics where nobody could see it: under the car. The Lotus 79 shaped its whole underside as two narrowing tunnels, so the air rushing beneath sped up and its pressure fell — sucking the car onto the track like a giant upside-down aircraft wing. It won the 1978 championship at a canter, and its idea rules Formula 1 again today.
· WHY IT MATTERED
A wing makes downforce but drags a big paddle through the air. The floor makes it by squeezing air through a narrowing tunnel — Bernoulli’s principle, the same one that explains an aircraft wing — at almost no drag cost. The 79 cornered like nothing before while losing little straight-line speed.
· WHY IT MATTERED
The suction only works if air can’t leak in from the sides. Sliding "skirts" ran along the sidepods, touching the track and sealing the tunnels. Lose a skirt and the downforce vanished instantly — which is why the demo’s ride-height slider is so touchy.
· WHY IT MATTERED
Ground effect grows viciously as the floor nears the road — until the flow chokes and stalls, dumping the downforce mid-corner. Cars began bouncing on their own suction ("porpoising", the same word used in 2022). After fatal accidents, flat floors were mandated in 1983.
· TRY IT
Air enters under the nose, accelerates through the narrow throat beneath the car, and slows again in the diffuser — faster air, lower pressure, and the track pulls the car down onto itself. Lower the ride height and watch the suction grow… then find the edge where the floor stalls.
Continuity squeezes the air faster through the throat; Bernoulli says faster means lower pressure; the road pulls the car down onto itself. Almost no drag is paid, because nothing is dangled in the wind — the reason ground effect returned in 2022.
Timelines · Formula 1 · component · Lotus 79
The humble plastic strips that the whole ground-effect trick depended on.
Composite blade, ceramic rubbing strip, spring-loaded·~50 mm of vertical float in the channel·Wear or jamming → instant loss of floor suction·Restricted 1981, banned with flat floors 1983
· WHAT IT DOES
The Lotus 79’s underbody suction only works if air can’t sneak in from the sides — so along each sidepod hung a “skirt”: a stiff strip in a channel, pushed down by springs so its ceramic rubbing edge stayed in contact with the road. Those strips carried the whole system: a worn edge or a jammed skirt and half the car’s grip evaporated between one corner and the next.
· WHY IT MATTERS
The floor, the road and the two skirts form a box of low-pressure air. Any gap is a leak straight from the high-pressure outside world, and the suction fades exponentially as the gap grows — millimetres matter, as the demo shows.
· WHY IT MATTERS
The car rolls, pitches and rides kerbs, so a fixed strip would either drag or gape. The skirt floats in its channel, springs holding the edge on the road through every movement — a suspension system for a piece of plastic.
· WHY IT MATTERS
When a skirt stuck up mid-corner, the downforce vanished without warning — a mechanical failure with aerodynamic consequences. Sliding skirts were restricted in 1981 and dead by 1983; the 2022 ground-effect rules manage the same sealing problem with shaped floor edges and vortices instead.
· TRY IT
Open a gap under the skirt and outside air floods the tunnels, killing the pressure difference. Slide the wear and watch the floor’s downforce drain away millimetre by millimetre — the maintenance item that decided championships.
The suction decays exponentially with the gap because the leak flow feeds directly on the pressure difference it destroys. Teams measured skirt wear in tenths of a millimetre — championship margins lived in this slider’s first few ticks.