Ford’s position as rally race heavyweights, emphasized by the success of the Ford Escort RS1600 and RS1800, had suffered after the closure of after the closure of the company’s Advanced Vehicle Operations (AVO) division, which had created these models. In the 1980s, Ford Motorsport (European division) tried to ensure a return to the top. It would need vehicles that fit the bill to put this in effect. Among them was the Sierra Cosworth.
The Sierra RS arrived on the scene in 1986, attempting to balance the blend of performance and affordability that is the vital sweet spot for vehicle sales. At £16,000 (approximately $19,600) at the time, drivers got a package with a T.03b turbocharger crafted by Garrett, a Garrett AiResearch T3, and a hefty YB engine, significant bang for their buck. In terms of performance, it offered a respectable 201bhp and a 375 bhp race trim.
In order to be eligible for rally racing, 5,000 model sales were required. It achieved just that early in 1987, and work began on the RS500, which Cosworth would soup up to a staggering 500bhp (204bhp on the road). Mike Moreton writes in “Rallye Sport Fords: The Inside Story” that this was achieved through extraordinary additions: “Twin fuel injectors and revised cylinder-head ports were part of the list, as was a bigger capacity oil pump and better cooling from a larger water pump and radiator. A bigger crankshaft damper would also be needed because of the extra vibration.”
