Ford Sierra RS Cosworth

Ford Sierra RS Cosworth

The Ford Sierra RS Cosworth is one of the most important performance cars of the 1980s, a homologation special that brought genuine competition technology to the public road. When Ford and Cosworth joined forces to create a Group A touring car contender, the result was a four-cylinder turbocharged sedan that could embarrass sports cars costing twice as much.

The heart of the RS Cosworth was the legendary YBB engine -- a 1,993cc inline-four with a Cosworth-designed twin-cam 16-valve cylinder head and a Garrett T3 turbocharger. In road trim, the engine produced 204 horsepower at 6,000 rpm, but the engineering headroom was enormous. Competition versions regularly exceeded 350 horsepower, and some qualifying tunes reached over 500 horsepower from the same basic architecture.

The Cosworth engine's construction was competition-grade throughout. Forged crankshaft, forged connecting rods, and cast pistons provided the bottom end with exceptional durability. The twin-cam cylinder head featured large valves, polished ports, and hydraulic lifters that eliminated the need for periodic valve adjustment. The fuel injection system was a Weber-Marelli electronic setup that provided precise fuel delivery under all conditions.

The most visually distinctive feature of the Sierra RS Cosworth was its enormous rear wing, designed by the Aachen wind tunnel laboratory. This was not a styling exercise -- the wing generated significant downforce at speed, dramatically improving high-speed stability and rear-end grip. Combined with front spoiler and side skirts, the aerodynamic package made the Sierra RS Cosworth a genuine 150 mph car that remained planted and stable.

The chassis was based on the standard Sierra three-door body with significant modifications. The suspension was lowered and stiffened, with revised spring rates, larger anti-roll bars, and Bilstein monotube shock absorbers. The braking system used ventilated discs at the front with four-piston calipers, providing the stopping power to match the engine's performance. The rear-wheel drive layout ensured engaging handling, though the turbo's power delivery required respect in wet conditions.

Inside, the RS Cosworth received Recaro sport seats, a leather-wrapped steering wheel, boost gauge, and various RS-specific trim details. The interior was purposeful rather than luxurious, reflecting the car's competition origins.

The Sierra RS Cosworth's racing record validated its homologation purpose emphatically. In the hands of teams like Andy Rouse Engineering and Eggenberger Motorsport, the car won European Touring Car Championships and dominated national series across Europe. Its success on track drove exceptional demand for the road car.

Ford initially planned to build just 5,000 units for homologation, but demand was so strong that production ultimately exceeded 6,000 three-door models before the car evolved into the Sierra RS500 and later the four-door Sapphire RS Cosworth.

The Sierra RS Cosworth has appreciated significantly in value as recognition of its importance in motorsport history has grown. Clean, unmodified examples are increasingly rare, as many were modified or driven hard by their original owners.