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). At the rear of the 2J were housed two fans (sourced from a military tank engine) driven by a single two stroke twin cylinder engine. 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, thereby providing a zone within which the fans could create a partial vacuum which would provide a downforce on the order of 1.25–1.50 G of the car fully loaded (fuel, oil, coolant). This gave the car tremendous gripping power and enabled greater maneuverability at all speeds. Since it created the same levels of low pressure under the car at all speeds, down-force did not decrease at lower speeds. With other aerodynamic devices, down-force decreases as the car slows down or…