The Sierra project was instigated in 1983 by the head of Ford Motorsport to create a competitive competition car. Ford then engaged Cosworth, who had developed the likes of DFV engines for Ford in the sixties and seventies (Cosworth-Ford were very successful in Formula 1 at this period). The Sierra 3-door was selected as the base vehicle, and they improved the Sierra’s performance by fitting a turbocharger and twin overhead camshafts, along with other modifications to achieve a much greater performing Sierra RS Cosworth. The car also featured lowered suspension and aerodynamic aids such as the strategically placed rear spoiler, with comments on the car saying it had an adequate aerodynamic drag.
The RS Cosworth helped to improve the poor, and somewhat undeserved, reputation that the Sierra had earned since its introduction in 1982. It was identifiable in difference to the standard Ford Sierra family saloon thanks to its RS body kit, large rear-spoiler and modified front grille and bumper. Initially 500 cars had to be manufactured for homologation purposes, relating to Group A racing. Production spanned 1986 to 1992 with further models such as the Sierra Sapphire 4-door RS Cosworth and the more powerful Sierra RS Cosworth 500. The car was only offered in three exterior colours (black, white and ‘moonstone’ blue) and one interior colour (grey). The Sierra Cosworth was highly successful car both in rallying and racing, providing a ‘Halo’ effect for the rest of the Ford range.
The Sierra RS Cosworth on display at Dundee Museum of Transport is a 1st generation 3-door model with a 5-speed manual gearbox. Its layout is a front longitudinal engine, which drives the rear wheels. A Cosworth 4-cylinder YBD 1993cc, Garrett Turbocharger, twin camshaft engine develops 204 bhp. It performs 0-60 in 6.5 seconds and has a top speed of 149 mph.