Ford Sierra RS Cosworth
Encyclopedia
The Ford Sierra RS Cosworth was a high-performance version of the Ford Sierra
. It was the result of a Ford Motorsport project with the purpose of producing an outright winner for Group A racing in Europe.
Turner got in touch with Walter Hayes
, at the time 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 Sixties and Seventies. 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 company Cosworth
, where they were presented a project developed on Cosworth’s own initiative, the YAA engine. This was 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 less 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 gear box proved more challenging. The Borg-Warner T5, also used in the Ford Mustang
, was chosen, but the higher revving
nature of the Sierra caused some problems. Eventually Borg-Warner had to set up a dedicated production line for the gear boxes to be used in the Sierra RS Cosworth.
Many of the suspension differences between the standard Sierra and the Cosworth attributed their development to what was learned from racing the turbocharged Jack Roush
IMSA
Merkur XR4Ti
in America and Andy Rouse
's successful campaign of the 1985 British Saloon Car Championship. Much of Ford's external documentation for customer race preparation indicated "developed for the XR4Ti" when describing parts that were Sierra Cosworth specific. Roush's suspension and aerodynamics engineering for the IMSA cars was excellent feedback for Ford. Some production parts from the XR4Ti made their way into the Cosworth such as the speedometer with integral boost gauge and the motorsport 909 chassis stiffening plates.
In April 1983, Turner’s team decided on the Sierra
as a basis for their project. The Sierra filled the requirements for rear wheel drive and decent aerodynamic drag. A racing version could also help to improve the unfortunate, and somewhat undeserved, reputation that Sierra had earned since the introduction in 1982.
Lothar Pinske, responsible for the car’s bodywork, demanded carte blanche when it came to appearance in order to make the car stable at high speed. Experience had shown that the Sierra hatchback body generated significant aerodynamic lift even at relatively moderate speed.
After extensive wind tunnel testing and test runs at the Nardò
circuit in Italy, a prototype was presented to the project management. This was based on an XR4i body with provisional body modifications in fibreglass and aluminium. The car’s appearance raised little enthusiasm. The large rear wing caused particular reluctance. Pinske insisted however that the modifications were necessary to make the project successful. The rear wing was essential to retain ground contact at 300 km/h, the opening between the headlights was needed to feed air to the intercooler and the wheel arch extensions had to be there to house wheels 10” wide on the racing version. Eventually, the Ford designers agreed to try to make a production version based on the prototype.
In 1984 Walter Hayes paid visits to many European Ford dealers in order to survey the sales potential for the Sierra RS Cosworth. A requirement for participation in Group A was that 5,000 cars were built and sold. The feedback was depressing. The dealers estimated they could sell approximately 1,500 cars.
Hayes didn’t give up however, and continued his passionate internal marketing of the project. As prototypes started to emerge, dealers were invited to test drive sessions, and this increased the enthusiasm for the new car. In addition, Ford took some radical measures to reduce the price on the car. As an example, the car was only offered in three exterior colours (black, white and moonstone blue) and one interior colour (grey). There were also just two equipment options: with or without central locking and electric window lifts.
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 3 door RS500 Cosworth. The vehicle was manufactured in both RHD (Right Hand Drive) for the UK market, and LHD (Left Hand Drive) for Europe. The following number of vehicles were registered in the UK:
in 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 3 door Cosworth was the uprated Cosworth competition engine. Its new features were :
The RS500 also had minor external cosmetic differences to its parent the Sierra 3 door Cosworth:
Exactly 500 RS500s were produced, all of them RHD for sale in the UK only - the biggest market for this kind of Ford car. It was originally intended that all 500 would be black, but in practice 56 white and 52 Moonstone Blue cars were produced .
In August 1987 the Sierra RS500 Cosworth was homologated. Fords took pole position in all the remaining six events, and was first over the finishing line in five of them. Disqualification from the 1987 James Hardie 1000
for wheel arch panel irregularities though was a bitter pill for the Fords, depriving Steve Soper
and Pierre Dieudonné
of the World Championship and handing it to BMW driver Roberto Ravaglia
. The Eggenberger Motorsport team did however claim the entrants prize.
The Sierra Cosworth was also pressed into service as a rally car, and saw some success. After the abolition of the Group B
formula in the World Rally Championship
at the end of 1986, manufacturers had to turn to Group A cars and Ford, like most others, found itself without a fully suitable car. The Cosworth was very powerful but, with only rear-wheel-drive, lost out to the four-wheel-drive Lancias and Mazdas on loose-surface events, whilst the four-wheel-drive XR4x4 had an excellent chassis but an elderly engine producing only around 200 bhp, at least 100 less than the Lancia. For the 1987 season the team ran both, using the XR4x4 on loose surfaces and the Cosworth on tarmac, but the XR4x4's power disadvantage was too great and from 1988 the team concentrated on the Cosworth alone, and continued to use it until the arrival of the Sierra RS Cosworth 4x4 in 1990.
The rear-drive car never won a loose-surface World Rally Championship event, but in the hands of drivers such as Stig Blomqvist
, Carlos Sainz
and Ari Vatanen
it frequently finished in the top five, except when conditions were particularly slippery. On tarmac it was a much more serious competitor, and a young Didier Auriol
won the 1988 Corsica Rally outright, the only time that season that Lancia were beaten in a straight fight. However, as Lancia developed the Delta further and new cars such as the Toyota Celica GT4 appeared, the Cosworth became steadily less competitive.
Thanks to strong support and readily available parts from Ford Motorsport, the Cosworth was a popular car with private teams. Moreover, below World Championship level four-wheel-drive opposition was limited at the time, and the Cosworth was as fast as any of its two-wheel-drive rivals. It lacked the fine handling of the BMW M3, for example, but on the other hand it was much more powerful. It was also very reliable. Consequently it became a very popular car at national championship level, and during the late 1980s Sierra drivers won many national series. Jimmy McRae
took the British Rally Championship
in a Sierra in 1987 and 1988, whilst Carlos Sainz won the Spanish Championship in the same years, to name but two. The Cosworth was popular with spectators because it was visually dramatic, with its flame-spitting exhaust and tail-sliding, rear-drive handling; and it was popular with amateur drivers because it was competitive, robust and relatively cheap. To this day it is a fairly common sight on lower-level events.
In the UK, the RHD 1988-1989 Sierra Sapphire RS Cosworth is badged as such with a small "Sapphire" badge on the rear door window trims. All 1988-1989 LHD models are badged and registered as a Sierra RS Cosworth 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. Enthusiasts of the marque are mindful of this and will describe the LHD cars by their body shell configuration, 3 door or 4 door. Example: 4 door Sierra RS Cosworth.
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 louvers. According to Ford’s own publicity material, 80% of the engine parts were also modified. The improved engine was designated YBJ for cars without a catalyst and YBG for cars with a catalyst. The latter 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
. This was to some extent a Sierra RS Cosworth clad in an "Escort-like" body. The car was released in May 1992, and was homologated for Group A rally in December, just as the Sierra RS Cosworth was retired.
The 4x4 Cosworth made a few appearances as a works rally car in 1990, and then tackled a full World Championship programme for 1991 and 1992. It was not a great success and never won a World Championship event, although in the hands of drivers such as Francois Delecour
and Massimo Biasion
it did take several second and third places. Initially it was unreliable, the gearbox being an especially weak point, and although by 1992 the reliability problems had been solved the Cosworth was never quite as effective in most conditions as some of its rivals. It was a relatively large car, slightly heavy, and less sophisticated than the latter generations of the Lancia Delta and Toyota Celica in terms of transmission systems and electronics. Biasion was reputedly strongly critical of the car on his first events for the team in 1992, but earned its best World Championship finish on that year's Rally of Portugal, where he finished second. He also brought its World Championship career to a close with fifth place on that Lombard RAC Rally. By then technical development of the Sierra had ceased, and most of the team's effort was directed towards the upcoming Escort Cosworth, which promised to be a much more competitive prospect.
Like the rear-drive car, the Cosworth 4x4 was popular at lower levels of rallying and a consistent winner at national championship level, and it remains a popular car among amateur rally drivers.
Ford Sierra
The Ford Sierra is a large family car that was built by Ford Europe from 1982 until 1993. It was designed by Uwe Bahnsen, Robert Lutz and Patrick le Quément. The code used during development was "Project Toni"....
. It was the result of a Ford Motorsport project with the purpose of producing an outright winner for Group A racing in Europe.
Development
The project was defined by Stuart Turner in the spring of 1983. He had then recently been appointed head of Ford Motorsport in Europe, and he realized right away that Ford was no longer competitive in this area.Turner got in touch with Walter Hayes
Walter Hayes
Walter Hayes CBE was an English journalist, and later public relations executive for Ford.Hayes was key in developing Ford's Formula One program, by signing Jackie Stewart and funding the building of the Cosworth DFV V8 Formula One racing engine; and the creation of the Premier Automotive Group...
, at the time 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
Ford GT40
The Ford GT40 was a high performance sports car and winner of the 24 hours of Le Mans four times in a row, from 1966 to 1969...
that won Le Mans
Le Mans
Le Mans is a city in France, located on the Sarthe River. Traditionally the capital of the province of Maine, it is now the capital of the Sarthe department and the seat of the Roman Catholic diocese of Le Mans. Le Mans is a part of the Pays de la Loire region.Its inhabitants are called Manceaux...
in 1966, and the Cosworth DFV
Cosworth DFV
The DFV is an internal combustion engine that was originally produced by Cosworth for Formula One motor racing. Named Four Valve because of the four valves per cylinder, and Double as it was a V8 development of the earlier, four-cylinder FVA , making it a Double Four Valve engine...
engine that brought Ford 154 victories and 12 World Championships in Formula One
Formula One
Formula One, also known as Formula 1 or F1 and referred to officially as the FIA Formula One World Championship, is the highest class of single seater auto racing sanctioned by the Fédération Internationale de l'Automobile . The "formula" designation in the name refers to a set of rules with which...
during the Sixties and Seventies. 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 company Cosworth
Cosworth
Cosworth is a high performance engineering company founded in London in 1958, specialising in engines and electronics for automobile racing , mainstream automotive and defence industries...
, where they were presented a project developed on Cosworth’s own initiative, the YAA engine. This was twin cam, 16-valve engine based on Ford’s own T88 engine block, better known as the Pinto
Ford Pinto engine
The Ford Pinto engine was the unofficial but generic nickname for a 4-cylinder internal combustion engine built by Ford Europe. In Ford sales literature it was referred to as the EAO or OHC engine and because it was designed to the metric system, it was sometimes called the "Metric engine". The...
. This prototype proved an almost ideal basis for the engine Turner needed to power his Group A
Group A
In relation to motorsport governed by the FIA, Group A referred to a set of regulations providing production-derived vehicles for outright competition. In contrast to the short-lived Group B and Group C, the Group A referred to production-derived vehicles limited in terms of power, weight, allowed...
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 less 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 gear box proved more challenging. The Borg-Warner T5, also used in the Ford Mustang
Ford Mustang
The Ford Mustang is an automobile manufactured by the Ford Motor Company. It was initially based on the second generation North American Ford Falcon, a compact car. Introduced early on April 17, 1964, as a "1964½" model, the 1965 Mustang was the automaker's most successful launch since the Model A...
, was chosen, but the higher revving
Revolutions per minute
Revolutions per minute is a measure of the frequency of a rotation. It annotates the number of full rotations completed in one minute around a fixed axis...
nature of the Sierra caused some problems. Eventually Borg-Warner had to set up a dedicated production line for the gear boxes to be used in the Sierra RS Cosworth.
Many of the suspension differences between the standard Sierra and the Cosworth attributed their development to what was learned from racing the turbocharged Jack Roush
Jack Roush
Jack Roush is the founder, CEO, and co-owner along with John Henry of Roush Fenway Racing, a NASCAR team headquartered in Concord, North Carolina, and is Chairman of the Board of Roush Enterprises....
IMSA
IMSA
IMSA can refer to:* International Management Systems Association, original name of the International Project Management Association * Illinois Mathematics and Science Academy, a residential magnet school located in Aurora, Illinois...
Merkur XR4Ti
Merkur XR4Ti
The Merkur XR4Ti was a short-lived United States and Canada-market version of the European Ford Sierra XR4i. It was the brainchild of then Ford Vice President Bob Lutz. It was sold in the US from 1985 to 1989. It was the first vehicle of Ford's Merkur range, followed in 1988 by the Merkur Scorpio...
in America and Andy Rouse
Andy Rouse
Andrew "Andy" Rouse is an English racing driver, most notably in the BTCC. He won the BTCC in 1975, 1983, 1984 and 1985....
's successful campaign of the 1985 British Saloon Car Championship. Much of Ford's external documentation for customer race preparation indicated "developed for the XR4Ti" when describing parts that were Sierra Cosworth specific. Roush's suspension and aerodynamics engineering for the IMSA cars was excellent feedback for Ford. Some production parts from the XR4Ti made their way into the Cosworth such as the speedometer with integral boost gauge and the motorsport 909 chassis stiffening plates.
In April 1983, Turner’s team decided on the Sierra
Ford Sierra
The Ford Sierra is a large family car that was built by Ford Europe from 1982 until 1993. It was designed by Uwe Bahnsen, Robert Lutz and Patrick le Quément. The code used during development was "Project Toni"....
as a basis for their project. The Sierra filled the requirements for rear wheel drive and decent aerodynamic drag. A racing version could also help to improve the unfortunate, and somewhat undeserved, reputation that Sierra had earned since the introduction in 1982.
Lothar Pinske, responsible for the car’s bodywork, demanded carte blanche when it came to appearance in order to make the car stable at high speed. Experience had shown that the Sierra hatchback body generated significant aerodynamic lift even at relatively moderate speed.
After extensive wind tunnel testing and test runs at the Nardò
Nardò
Nardò is a town and comune of 31,185 inhabitants and comune in the southern Italian region of Apulia, in the province of Lecce.-History:...
circuit in Italy, a prototype was presented to the project management. This was based on an XR4i body with provisional body modifications in fibreglass and aluminium. The car’s appearance raised little enthusiasm. The large rear wing caused particular reluctance. Pinske insisted however that the modifications were necessary to make the project successful. The rear wing was essential to retain ground contact at 300 km/h, the opening between the headlights was needed to feed air to the intercooler and the wheel arch extensions had to be there to house wheels 10” wide on the racing version. Eventually, the Ford designers agreed to try to make a production version based on the prototype.
In 1984 Walter Hayes paid visits to many European Ford dealers in order to survey the sales potential for the Sierra RS Cosworth. A requirement for participation in Group A was that 5,000 cars were built and sold. The feedback was depressing. The dealers estimated they could sell approximately 1,500 cars.
Hayes didn’t give up however, and continued his passionate internal marketing of the project. As prototypes started to emerge, dealers were invited to test drive sessions, and this increased the enthusiasm for the new car. In addition, Ford took some radical measures to reduce the price on the car. As an example, the car was only offered in three exterior colours (black, white and moonstone blue) and one interior colour (grey). There were also just two equipment options: with or without central locking and electric window lifts.
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 3 door RS500 Cosworth. The vehicle was manufactured in both RHD (Right Hand Drive) for the UK market, and LHD (Left Hand Drive) for Europe. The following number of vehicles were registered in the UK:
| 1985 | 10 |
| 1986 | 1064 |
| 1987 | 579 |
| Total | 1653 |
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 MartinAston Martin
Aston Martin Lagonda Limited is a British manufacturer of luxury sports cars, based in Gaydon, Warwickshire. The company name is derived from the name of one of the company's founders, Lionel Martin, and from the Aston Hill speed hillclimb near Aston Clinton in Buckinghamshire...
in Tickford
Tickford
Tickford is an automobile engineering and testing company with a history of coachbuilding and tuning and is famous for such products as the 140 mph Tickford Turbo Capri.-Early years:...
was signed for the job of converting the 500 cars.
The Cosworth RS500 was announced in July 1987 and was homologated
Homologation
Homologation is a technical term, derived from the Greek homologeo for "to agree", which is generally used in English to signify the granting of approval by an official authority...
in August 1987.
The main difference to the Sierra 3 door Cosworth was the uprated Cosworth competition engine. Its new features were :
- The engine had a thicker walled cylinder block to cope with the rigours of the track.
- A larger Garrett T31/T04 turbocharger.
- A larger air-air intercooler.
- A second set of 4 fuel injectors and a second fuel rail (unused in the roadgoing version).
- The fuel pump was uprated.
- A reworked induction system to allow higher power outputs to be realised.
- The oil and cooling system were both also uprated.
- The rear semi-trailing arm beam had extended but unused mounting points.
The RS500 also had minor external cosmetic differences to its parent the Sierra 3 door Cosworth:
- The rear tail gate had a lower spoiler in addition to the upper whale tail, which had an added lip.
- Discrete RS500 badges on the rear tail gate 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, all of them RHD for sale in the UK only - the biggest market for this kind of Ford car. It was originally intended that all 500 would be black, but in practice 56 white and 52 Moonstone Blue cars were produced .
Motorsport achievements
The car also fulfilled Ford's expectations on the race track. The 1987 World Touring Car Championship came like a gift to Ford. Competent BMW drivers, some trouble with gear boxes, amongst other things, and only 340 HP in the first Sierra RS Cosworth prevented Ford from dominating the first half of the season.In August 1987 the Sierra RS500 Cosworth was homologated. Fords took pole position in all the remaining six events, and was first over the finishing line in five of them. Disqualification from the 1987 James Hardie 1000
1987 James Hardie 1000
The 1987 James Hardie 1000 was the eighth round of the inaugural World Touring Car Championship, the first round to be held in the southern hemisphere. The race was held for cars eligible for Group A touring car regulations. It was the 25th anniversary of the original touring car endurance race...
for wheel arch panel irregularities though was a bitter pill for the Fords, depriving Steve Soper
Steve Soper
Steve Soper is a retired racing driver from Surrey, England, born in 1951. He raced in sports cars and touring cars at the top level for over 20 years. In 1983 he almost won the British Touring Car Championship before his Rover was deemed illegal. He finished as runner-up in the series in 1988 in a...
and Pierre Dieudonné
Pierre Dieudonné
Pierre Dieudonné is a Belgian auto racing driver.-Career:He spent a large part of his career competing in Touring car racing. He twice finished third in the European Touring Car Championship in 1977 and 1979. He won two consecutive Spa 24 Hours in 1974 and 1975 with a BMW 3.0 CSi...
of the World Championship and handing it to BMW driver Roberto Ravaglia
Roberto Ravaglia
Roberto Ravaglia is a former auto racing driver, who currently runs ROAL Motorsport, who operate the BMW Team Italy-Spain operation in the World Touring Car Championship...
. The Eggenberger Motorsport team did however claim the entrants prize.
The Sierra Cosworth was also pressed into service as a rally car, and saw some success. After the abolition of the Group B
Group B
Group B was a set of regulations introduced in 1982 for competition vehicles in sportscar racing and rallying regulated by the FIA. The Group B regulations fostered some of the quickest, most powerful and sophisticated rally cars ever built. However, a series of major accidents, some fatal, were...
formula in the World Rally Championship
World Rally Championship
The World Rally Championship is a rallying series organised by the FIA, culminating with a champion driver and manufacturer. The driver's world championship and manufacturer's world championship are separate championships, but based on the same point system. The series currently consists of 13...
at the end of 1986, manufacturers had to turn to Group A cars and Ford, like most others, found itself without a fully suitable car. The Cosworth was very powerful but, with only rear-wheel-drive, lost out to the four-wheel-drive Lancias and Mazdas on loose-surface events, whilst the four-wheel-drive XR4x4 had an excellent chassis but an elderly engine producing only around 200 bhp, at least 100 less than the Lancia. For the 1987 season the team ran both, using the XR4x4 on loose surfaces and the Cosworth on tarmac, but the XR4x4's power disadvantage was too great and from 1988 the team concentrated on the Cosworth alone, and continued to use it until the arrival of the Sierra RS Cosworth 4x4 in 1990.
The rear-drive car never won a loose-surface World Rally Championship event, but in the hands of drivers such as Stig Blomqvist
Stig Blomqvist
"Stig" Lennart Blomqvist is a Swedish rally driver. He made his international breakthrough in 1971. Driving an Audi Quattro for the Audi factory team, Blomqvist won the World Rally Championship drivers' title in 1984 and finished runner-up in 1985...
, Carlos Sainz
Carlos Sainz
Carlos Sainz Cenamor is a Spanish rally driver. He won the World Rally Championship drivers' title with Toyota in 1990 and 1992, and finished runner-up four times...
and Ari Vatanen
Ari Vatanen
Ari Pieti Uolevi Vatanen is a Finnish rally driver turned politician and Member of the European Parliament 1999–2009. Vatanen won the World Rally Championship drivers' title in 1981 and the Paris Dakar Rally four times....
it frequently finished in the top five, except when conditions were particularly slippery. On tarmac it was a much more serious competitor, and a young Didier Auriol
Didier Auriol
Didier Auriol is a French rally driver.Born in Montpellier, and initially an ambulance driver, Auriol made his name as a French rally driver in the World Rally Championship throughout the 1990s. He became World Rally Champion in 1994, the first from his country to do so...
won the 1988 Corsica Rally outright, the only time that season that Lancia were beaten in a straight fight. However, as Lancia developed the Delta further and new cars such as the Toyota Celica GT4 appeared, the Cosworth became steadily less competitive.
Thanks to strong support and readily available parts from Ford Motorsport, the Cosworth was a popular car with private teams. Moreover, below World Championship level four-wheel-drive opposition was limited at the time, and the Cosworth was as fast as any of its two-wheel-drive rivals. It lacked the fine handling of the BMW M3, for example, but on the other hand it was much more powerful. It was also very reliable. Consequently it became a very popular car at national championship level, and during the late 1980s Sierra drivers won many national series. Jimmy McRae
Jimmy McRae
Jimmy McRae is a Scottish rally driver. He is the father of World Rally Championship drivers Alister McRae, and the late 1995 World Rally Champion Colin McRae...
took the British Rally Championship
British Rally Championship
The Dulux Trade MSA British Rally Championship is a yearly rallying series based in the United Kingdom. It comprises seven events with eight scoring opportunities throughout the British Isles. The first championship was run in 1958 and it has been licensed by the MSA Motor Sports Association since...
in a Sierra in 1987 and 1988, whilst Carlos Sainz won the Spanish Championship in the same years, to name but two. The Cosworth was popular with spectators because it was visually dramatic, with its flame-spitting exhaust and tail-sliding, rear-drive handling; and it was popular with amateur drivers because it was competitive, robust and relatively cheap. To this day it is a fairly common sight on lower-level events.
2wd Sierra Sapphire RS Cosworth
The second generation 4 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 2wd heads and also the "later" 2wd 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 LHD models 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 Cosworth is badged as such with a small "Sapphire" badge on the rear door window trims. All 1988-1989 LHD models are badged and registered as a Sierra RS Cosworth 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. Enthusiasts of the marque are mindful of this and will describe the LHD cars by their body shell configuration, 3 door or 4 door. Example: 4 door Sierra RS Cosworth.
Sierra RS Cosworth 4×4
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 Borg Warner T75 gear box 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 louvers. According to Ford’s own publicity material, 80% of the engine parts were also modified. The improved engine was designated YBJ for cars without a catalyst and YBG for cars with a catalyst. The latter 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
Ford Mondeo
The Mondeo was launched on 8 January 1993, and sales began on 22 March 1993. Available as a four-door saloon, a five-door hatchback, and a five-door estate, all models for the European market were produced at Ford's plant in the Belgian city of Genk...
. The replacement for the Sierra RS Cosworth was not a Mondeo however, but the Escort RS Cosworth
Ford Escort RS Cosworth
The Ford Escort RS Cosworth was a sports derivative of the Ford Escort. It was available from 1992-96 in very limited numbers.It was instantly recognisable due to its large "whale tail" rear spoiler...
. This was to some extent a Sierra RS Cosworth clad in an "Escort-like" body. The car was released in May 1992, and was homologated for Group A rally in December, just as the Sierra RS Cosworth was retired.
The 4x4 Cosworth made a few appearances as a works rally car in 1990, and then tackled a full World Championship programme for 1991 and 1992. It was not a great success and never won a World Championship event, although in the hands of drivers such as Francois Delecour
François Delecour
François Delecour is a rally driver.In the employ of Ford Motor Company as a driver of the factory-fettled Ford Escort RS Cosworth, he finished as runner-up in drivers' standings in the 1993 World Rally Championship season. He was still driving for Ford by January 1994, when he won the...
and Massimo Biasion
Massimo Biasion
Massimo 'Miki' Biasion is an Italian rally driver, two times world rally champion.-Career:Born at Bassano del Grappa, Biasion came to prominence in the early 1980s, winning both the Italian and European Rally Championships in 1983, driving a Lancia 037...
it did take several second and third places. Initially it was unreliable, the gearbox being an especially weak point, and although by 1992 the reliability problems had been solved the Cosworth was never quite as effective in most conditions as some of its rivals. It was a relatively large car, slightly heavy, and less sophisticated than the latter generations of the Lancia Delta and Toyota Celica in terms of transmission systems and electronics. Biasion was reputedly strongly critical of the car on his first events for the team in 1992, but earned its best World Championship finish on that year's Rally of Portugal, where he finished second. He also brought its World Championship career to a close with fifth place on that Lombard RAC Rally. By then technical development of the Sierra had ceased, and most of the team's effort was directed towards the upcoming Escort Cosworth, which promised to be a much more competitive prospect.
Like the rear-drive car, the Cosworth 4x4 was popular at lower levels of rallying and a consistent winner at national championship level, and it remains a popular car among amateur rally drivers.