The 1987 World Touring Car Championship was a controversial and political affair, but gave birth to two dominant models, the BMW M3 and Ford Sierra RS500 Cosworth.
Work began on the Sierra way back in 1985 when English ace Andy Rouse developed an early version for a successful tilt at the British Touring Car Championship.
For 1986, Ford furthered its program to include the European Touring Car Championship, which was led by Ruedi Eggenberger.
The Swiss tech whizz had won the previous year’s ETCC with Volvo, but changed allegiance to Ford where he swiftly began improving the Ford Sierra XR4Ti.
Funnily enough, the XR4Ti designation was never sold in Europe rather it was Ford’s attempt at rivalling the premium makes in the US through the Merkur brand, but this failed.
Eggenberger soon found failings in the XR4Ti platform and worked to improve these throughout the 1986 ETCC season. It proved a competitive testing bed as Tom Walkinshaw’s Rover team, RAS with Volvo, Schnitzer BMW and the occasional Holden threat ensured Ford had a strong product for the World Touring Car Championship.
This led to the RS Cosworth and latter RS500 homologation special versions of the Sierra.
Beginning the 1987 WTCC with the RS designation, BMW’s new M3 proved a match despite a disadvantage in the power stakes.
Improvements for the RS500 included to the engine and aerodynamics, but mainly to the rear end as combined with newly developed tyres by Pirelli, it made this specification almost unbeatable in the Eggenberger team’s hands.
However, this where a premium manufacturing was called in to aid the Ford attack.
Homologation requirements in Group A racing required 5000 of the base model to be produced and 500 Evolution versions to be produced.
Ford produced 5000 RS Cosworths and the Blue Oval engaged Aston Martin Tickford to produce the 500 RS500s.
Debuting at Round 6 of the WTCC at Brno, the RS500 went onto secure the remaining pole positions for the season and four victories, the fifth of which was a disqualification at Bathurst.
The RS500 dominated touring car racing globally until the demise of Group A in the early-1990s.