JS9 was the last Ligier car that used a Matra V12 with the 1979 car being designed around a Cosworth engine. For the 1978 season, Ligier continued to run
for the 1981 season, team owner Guy Ligier had arranged a supply of Talbot-badged Matra V12 engines. The V12 engine, designated the MS81 and newly developed
season, but the next generation of ground effects cars led first by the LigierJS11, then the Ferrari 312T4 and then the Williams FW07 — a car heavily based