8W – How? – Brabham BT46B: This is a great page about the legendary “fan car” of Formula One. The Fan Car used a fan (powered through the transmission) to eject air from under the car and basically suck itself down onto the track.
The basic concept of ground effects in auto racing requires that you create a low pressure zone under the car. If you can get some kind of vacuum under there, atmospheric pressure will push your car onto the track and enable you to corner at insane speeds.
(And downforce is everything. At speed, Formula One and Indy cars generate more downforce than they weigh, which means you could turn the track upside down and they would happily zip around it upside down, now being pushed up into the “ceiling.” Slowing down for hairpins would be a problem, though…)
Car designs create ground effects by various methods, usually involving a small inlet at the front of the car and an enlarged chamber under the car. A little air gets in, and then has to fill a big space, which drops its pressure, etc.
The Fan Car went a step further and used an actual fan at the rear to suck the air from under the car. It apparently worked insanely well:
The fan was so effective, that the car could be seen to suddenly squat downwards when the throttle was blipped in the pits.
The Fan Car won the first race in which it was ever entered — the 1978 Swedish Grand Prix. It was promptly banned, never to race again.
The page at the link above has a fantastic account of The Fan Car and the legacy it left behind.