Also available on the IROC was the new R/T performance package, which featured a 224 horsepower Turbo III version of the 2.2 L four-cylinder, but with a Lotus designed DOHC cylinder head and direct ignition system instead of a distributor-type ignition system; this engine was shared with the Dodge Spirit R/T. Although the Shelby trim was discontinued after 1991 (due to the end of Carroll Shelby's involvement with Chrysler), a small number of 1992 Daytona IROCs were produced bearing the Shelby name.