Ford · 1986–1992

Ford Sierra RS Cosworth

The Ford Sierra RS Cosworth is a high-performance version of the Ford Sierra that was built by Ford Europe from 1986 to 1992. It was the result of a Ford Motorsport project with the purpose of producing an outright winner for Group A racing in Europe.

Text from Wikipedia (CC BY-SA 4.0).

Predecessor: Ford RS200 · Successor: Ford Escort RS Cosworth

All Ford Sierra RS Cosworth data: UK builds, safety, recalls, model years →

Development

The project was defined by Stuart Turner in the spring of 1983. He had recently been appointed head of Ford Motorsport in Europe, and realised that Ford was no longer competitive in this area. Turner got in touch with Walter Hayes, at the time the vice-president of public relations at Ford, to get support for the project. Hayes had earlier been the driving force behind the development of the Ford GT40 that won Le Mans in 1966, and the Cosworth DFV engine that brought Ford 154 victories and 12 world championships in Formula One during the 1960s and 1970s. Hayes found the project very appealing and promised his full support. Turner then invited Ken Kohrs, vice-president of development, to visit Ford's longtime partner, the automotive engineering company Cosworth, where they were presented a project developed on Cosworth's own initiative, the YAA engine. This was a twin cam, 16-valve engine based on Ford's own T88 engine block, better known as the Pinto. This prototype proved an almost ideal basis for the engine Turner needed to power his Group A winner. Therefore, an official request for a turbocharged version (designated Cosworth YBB) capable of 180 HP on the street and 300 HP in race trim, was placed. Cosworth answered positively, but they put up two conditions: the engine would produce not less than 150 kW (204 HP) in the street version, and Ford had to accept no fewer than 15,000 engines. Turner's project would only need about 5,000 engines, but Ford nevertheless accepted the conditions. The extra 10,000 engines would later become one of the reasons Ford also chose to develop a four-door, second generation, Sierra RS Cosworth. To find a suitable gearbox proved more challenging. The Borg-Warner T5, also used in the Ford Mustang, was chosen, but the higher revving natur

Production

The Ford Sierra RS Cosworth was first presented to the public at the Geneva Motor Show in March 1985, with plans to release it for sale in September and closing production of the 5,000 cars in the summer of 1986. In practice, it was launched in July 1986, and 5545 were manufactured in total, of which 500 were sent to Tickford for conversion to the Sierra three-door RS500 Cosworth. The vehicles were manufactured at Ford's Genk factory in Belgium in both Left and Right hand drive, with the Pre Production Prove out Process cars produced in February 1986 and the main production of the vehicle commencing summer 1986, the final cars off the production line were in December 1986. 3 colours were produced, Black, White and Moonstone Blue, with White and Moonstone Blue both seeing around 2/5th of the total number of Right Hand Drive models produced with Black cars around 1/5th. The following number of vehicles were registered in the UK: As published in the 1986 RS catalog: Max speed: 149 mph 0–60 mph: 6.5 sec Fuel consumption at 56 mph: 38.2 mpg Fuel consumption at 75 mph: 30.1 mpg Drag coefficient: 0.345 Rear spoiler: 20kgf at 150 mph Front brakes: Disc 28.3 cm diameter Rear brakes: Disc 27.3 cm diameter Differential: Viscous coupled limited slip Tyre size: 205/50 VRx15 Wheels: 15"x7" alloys

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 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 three-door Cosworth was Cosworth's uprated competition engine. Its new features were: The Inline-four engine had a thicker walled cylinder block and smaller core plugs A larger Garrett AiResearch T04 turbocharger A larger air-air intercooler A second set of four Weber IW025 "yellow" fuel injectors and a second fuel rail (not functional in the road version) An uprated fuel pump A larger capacity airbox and turbo inlet pipe Blow-off valve crossover pipe feed relocated to the inlet manifold An uprated oil and cooling system The rear semi-trailing arm beam had extended but unused mounting points Engine output increased to 227 PS (224 hp; 167 kW) at 6000 rpm Max. torque of 277 N⋅m (204 lb⋅ft) at 4500 rpm. The RS500 also had minor external cosmetic differences to its parent the Sierra three-door Cosworth: The rear tailgate had a lower spoiler in addition to the upper "whale tail" The upper "whale tail" had the standard car's trailing edge replaced with a more aggressive "gurney flap" for additional downforce Discreet RS500 badges on the rear tailgate 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 using the 500 Sierra RS Cosworth vehicles that were produced at Genk in December 1986, all of them RHD for sale in the UK only - the biggest market for this kind of Ford car

Motorsport achievements

=== Touring car racing === In August 1987 the Sierra RS500 Cosworth was homologated. Ford took pole position in all the remaining six 1987 World Touring Car Championship events and was first over the finish line in four of them. The works Eggenberger Motorsport team won the entrants' World Championship, although the team's cars were disqualified from the 1987 Bathurst 1000 in Australia for wheel arch panel irregularities. These had been deemed legal in every other race that year however this deprived Klaus Ludwig and Klaus Niedzwiedz of the drivers' title. Eggenberger won the 1989 Spa 24 Hours. Robb Gravett won the 1990 British Touring Car Championship in a RS500. The BTCC points system was such that divisions below the Sierra (3500cc & under, 2000cc & under) would gain more points for a class win therefore although the Sierra finished first in 9/12 rounds of the 1987 season and first in every race from 1988 to 1990 it only took the drivers title once in 1990. The RS500 was successful in the 1988 DTM with Klaus Ludwig in the Ford Team Grab winning the drivers championship and Wolf Racing winning the Team Championship. Both Grab and Wolf were Ford Works Teams and beat Mercedes-AMG along with BMW M Sport for the honours. For the 1989 season, the cars were reined in with even higher weight and boost penalties (partly due to protests from BMW and Mercedes who felt they were at a significant disadvantage) until they were no longer competitive, subsequently forced induction engines were banned for 1991 season onwards. Knowing they were unable to be competitive, Ford left the DTM at end of the 1989 season. The RS500 was successful in Australian touring car racing with Dick Johnson Racing dominating the 1988 and 1989 Australian Touring Car Championships, with Dick Johnson and

Sierra Sapphire RS Cosworth (RWD)

The second generation four-door Sierra Sapphire Cosworth was assembled in Genk, Belgium, with the UK-built Ford-Cosworth YBB engine. Cylinder heads on this car were early spec two wheel drive heads and also the "later" two wheel drive head which had some improvements which made their way to the 4X4 head. Suspension was essentially the same with some minor changes in geometry to suit a less aggressive driving style and favour ride over handling. Spindles, wheel offset and other changes were responsible for this effect. Approximately 13,140 examples were produced during 1988–1989 and were the most numerous and lightest of all Sierra Cosworth models. Specifically the left hand drive models (LHD) which saved weight with a lesser trim level such as roll up rear windows, no air conditioning etc. In the UK, the RHD 1988–1989 Sierra Sapphire RS Cosworths are badged with small "Sapphire" badges on the rear door window trims. All 1988–1989 LHD models are badged and registered as Sierra RS Cosworths with no Sapphire nomenclature at all. "Sapphire" being viewed as a Ghia trim level that saw power rear windows, air conditioning and other minor options. The Sapphire Cosworth, being based on a different shell to the original three-door Cosworth, along with its more discreet rear wing, recorded a drag co-efficient of 0.33, thus allowing it to register slightly better performance figures (top speed of 150 mph [240 km/h] and 0–60 mph [0–97 km/h] of 6.1 seconds) compared to the original Cosworth.

Sierra RS Cosworth 4x4

In January 1990 the third generation Sierra RS Cosworth was launched, this time with four wheel drive. As early as 1987, Mike Moreton and Ford Motorsport had been talking about a four-wheel drive Sierra RS Cosworth that could make Ford competitive in the World Rally Championship. The Ferguson MT75 gearbox that was considered an essential part of the project wasn't available until late 1989 however. Ford Motorsport's desire for a 3-door "Motorsport Special" equivalent to the original Sierra RS Cosworth was not embraced. The more discreet 4-door version was considered to have a better market potential. It was therefore decided that the new car should be a natural development of the second generation, to be launched in conjunction with the face lift scheduled for the entire Sierra line in 1990. The waiting time gave Ford Motorsport a good opportunity to conduct extensive testing and demand improvements. One example was the return of the bonnet louvres. According to Ford's own publicity material, 80% of the engine parts were also modified. The improved engine was designated YBG for cars with a catalytic converter and YBJ for cars without. The former had the red valve cover replaced by a green one, to emphasize the environmental friendliness. Four wheel drive and an increasing amount of equipment had raised the weight by 100 kg, and the power was therefore increased to just about compensate for this. The Sierra RS Cosworth 4x4 received, if possible, an even more flattering response than its predecessors and production continued until the end of 1992, when the Sierra was replaced by the Mondeo. The replacement for the Sierra RS Cosworth was not a Mondeo however, but the Escort RS Cosworth. Based on the Sierra Cosworth platform, the Escort went on sale in May 1992, more than a

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Specifications

name: Ford Sierra RS Cosworth
Manufacturer: Ford Europe
Production: 1986–1992
Assembly: Belgium: Genk (Genk Body & Assembly)
Body style: 3-door hatchback (1986–1987), 4-door saloon (1988–1992)
Engine: 2.0 L Cosworth YBD/YBG/YBJ turbo I4
Transmission: 5-speed manual, Borg Warner T5 (1986–1989), Ferguson 4x4 MT75 (1990–1992)
Length: 446 cm (1986–1987), 449 cm (1988–1992)
Layout: Front-engine, rear-wheel drive (1986–1989), Front-engine, all-wheel drive (1990–1992)
Width: 173 cm (1986–1987), 170 cm (1988–1992)
Height: 138 cm (1986–1992)
Kerb weight: 1217 kg (1986–1987), 1206 kg (1988–1989), 1305 kg (1990–1992)
Predecessor: Ford RS200
Successor: Ford Escort RS Cosworth
Designer: Lothar Pinske

Specification summary from Wikipedia (CC BY-SA 4.0). Check the linked sources for citations.

More photos

Sources

Wikidata — https://www.wikidata.org/wiki/Q4566760CC0 1.0 · retrieved 2026-10-01
Wikipedia — https://en.wikipedia.org/wiki/Ford_Sierra_RS_CosworthCC BY-SA 4.0 · Text © Wikipedia contributors; revision 1368078791 · retrieved 2026-10-01
Wikimedia Commons — https://commons.wikimedia.org/wiki/File:Cosworth800px.jpgPublic domain · Photo: Lemmus · retrieved 2026-10-01
Car Model Index — https://models.autoculturesociety.com/Compiled record. Sources that do not permit reuse are not copied; this index is credited instead.