The Brabham BT46 is a good example of what good creativity, mixed with engineering genius will create. The BT46B was known as the ‘fan-‘car’ designed to counter the strong ground-effects of the Lotus 79.
Powered by a three-liter Alfa-Romeo sourced flat 12
(520 bhp at 12,000 rpm), the car was ingeniously designed by Gordon Murray. (Who I believe to be the Adrian Newey of his day.)
The way that the car generated it’s strong downforce was through a fan at the rear, which designers had “claimed” was made for cooling the car. However, it add the “added benefit” of drawing air from underneath the car, creating strong downforce.
“Murray designed a version driven by a complex series of clutches running from the engine to a large single fan at the back of the car. Therefore the faster the engine ran, the stronger the suction effect. Like the Lotus, it had sliding “skirts” that sealed the gap between the sides of the cars and the ground. These prevented excessive air from being sucked into the low pressure area under the car and dissipating the ground effect.“- Wikipedia