Ford Sierra RS Cosworth
PRODUCTION.- 1986; approximate number built: 5,500; assembled at Genk, Belgium with UK-built Cosworth engine, Borg Warner five-speed gearbox and Ferguson Viscous Coupling rear drive.
Valve gear: four valves per cylinder, twin overhead camshafts, belt-drive. Fuel and ignition: Garrett Airesearch T03, compact air intercooler, Weber-Marelli microprocessor managed four injector injection and ignition. Installation: Front, longitudinal.
Type: Rear drive, Viscous Coupling limited slip differential.
Gearbox: Borg Warner TS.
Internal ratios: lst, 2.95; 2nd, 1.94; 3rd, 1.34; 4th, 1:1 direct; 5th, 0.80.
Final drive: 3.65:1, 22,79 mph per 1,000 rpm in 5th.
Front: Independent by McPherson struts, lower track control arms (TCAs), coaxial coil springs, Fichtel & Sachs twin tube gas damper inserts, 28 mm diameter front anti-roll bar.
Rear: Semi-trailing arms, uniball joints, coil springs in front of axle, separate telescopic F&S gas rear dampers, 14 mm rear anti-roll bar.
Type: Power assisted, Cam Gears/TRW rack and pinion, lock to lock: 2.6 turns.
Front: 283 mm, vented discs.
Rear: 273 mm solid back discs.
System: Hydraulically assisted, Alfred Teves GmbH electronic anti-lock action.
WHEELS AND TYRES
Wheels: unique Rial (BBS style) alloys, 7 x 15 in.
Tyres: 205150 VR (Dunlop D40 was Original Equipment).
Type: 3-dr hatchback Sierra L with Phoenix-manufactured body kit and rear wing to Ford design, wheelarch extensions, side sills, front bumper/spoiler with flexible rubber extension, twin bonnet louvres, air intake between headlights. Colour: Originally sold only in white, Moonstone blue metallic and black.
Construction: Steel monocoque with polyurethane and rubber body additions. Dimensions: Length, 4,458 mm; width, 1,727 mm; height, 1,377 mm; wheelbase, 2,609 mm: front track, 1,450 mm; rear track, 1,470 mm; weight, 1,205 kg.
PERFORMANCE AND ECONOMY (Manufacturer’s figures)
Max speed: 149.8 mph (240 km/h
Fuel consumption: 22.8 mpg urban; 38.2 mpg at constant 56 mph; 30.1 mpg at 75 mph.
Copyright Jan van Elderen