Ford Sierra RS Cosworth - Sierra RS500 Cosworth

Sierra RS500 Cosworth

Mike Moreton was head of the team that planned to develop an evolution edition aimed at making the car unbeatable on the race tracks. In March 1987, Aston Martin in Tickford was signed for the job of converting the 500 cars.

The Cosworth RS500 was announced in July 1987 and was homologated in August 1987.

The main difference to the Sierra 3 door Cosworth was the uprated Cosworth competition engine. Its new features were:

• The engine had a thicker walled cylinder block to cope with the rigours of the track.
• A larger Garrett T31/T04 turbocharger.
• A larger air-air intercooler.
• A second set of 4 fuel injectors and a second fuel rail (unused in the roadgoing version).
• The fuel pump was uprated.
• A reworked induction system to allow higher power outputs to be realised.
• The oil and cooling system were both also uprated.
• The rear semi-trailing arm beam had extended but unused mounting points.

The RS500 also had minor external cosmetic differences to its parent the Sierra 3 door Cosworth:

• The rear tail gate had a lower spoiler in addition to the upper whale tail, which had an added lip.
• Discrete RS500 badges on the rear tail gate and front wings.
• A redesigned front bumper and spoiler to aid cooling and air flow, including the removal of the fog lamps and their replacement with intake grilles to supplement brake cooling

Exactly 500 RS500s were produced, all of them RHD for sale in the UK only - the biggest market for this kind of Ford car. It was originally intended that all 500 would be black, but in practice 56 white and 52 Moonstone Blue cars were produced .