Although during the 1983 Formula 1 World Championship did not manage to gather much in the hands of Jean-Pierre Jarier and Raul Boesel, the Ligier JS21 is remembered as a completely unconventional single-seater. This is due to the total absence of the side parts, determined by the abolition of the skirts, and for its markedly arrow-shaped line. The car was characterized by many innovative elements, but it had to pay the price of not having been adequately developed following to the decision of the French team to design another single-seater to fit the Renault turbo engine. The engine used was therefore the Ford Cosworth 8 cylinder 90 ° V of 2.990 cm3 with a power of 505 hp. Built on a monocoque aluminum frame, the Ligier JS21 was equipped with double triangle front suspension and rear suspension with upper link and lower wishbone. Equipped with a 5-speed Hewland sequential manual transmission plus reverse, it had a dry weight of 540 kg and a wheelbase of 2,630 mm. The brakes were auto-ventilated steel disc brakes. Tires were supplied by Michelin.