Originally Posted by big john

There was a car called the Chapparral in the 60s with that and they were driving around the Ford GTs and the fan was quickly banned.

The most unusual Chaparral was the 2J. On the chassis' sides bottom edges were articulated plastic skirts that sealed against the ground (a technology that would later appear in Formula One). Two fans adapted from a military tank engine were housed at the rear, driven by a single two-stroke twin-cylinder engine.[5] The car had a "skirt" made of Lexan extending to the ground on both sides, laterally on the back of the car, and laterally from just aft of the front wheels. It was integrated with the suspension system so the bottom of the skirt would maintain a distance of one inch from the ground regardless of g-forces or anomalies in the road surface. The skirting produced a zone within which the fans could create a vacuum producing downforce on the order of 1.25 to 1.50 g when the car was fully loaded (fuel, oil, coolant).