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Group C: The Rise and Fall of the Golden Age of Endurance Racing: Cars and Constructors Part 7

Submitted by on January 6, 2020

By Marcel Hundscheid / Speed-O-Graphica

In this seventh part of our Group C retrospective, we focus on Jaguar’s final three cars that would participate under Group C regulations: the XJR-9, XJR-11, XJR-12 and the XJR-14.

At the 1988 Daytona 24 Hours Jaguar debuted the XJR-9, an evolution of the earlier XJR-8 designed by Tony Southgate.

They went on to enter five cars in the 24 Hours of Le Mans. Winning the great race doesn’t come easy, and the first car retired from the race early due to transmission problems, a second car followed, struck down by an engine problem.

This left just three cars to keep the dream alive, with Dutchmen Jan Lammers driving chassis J-12-C-488 in the lead. This car suffered from the same gearbox problems as the first, but Lammers noticed it and drove the rest of the race in 4th gear. Just a single gearshift would have ended Jaguar’s dream but thanks to Lammers, Andy Wallace and Johnny Dumfries, the British marque claimed their first Le Mans 24 Hour victory since 1957, breaking Porsche’s seven-year winning streak in the process.

Pictured below is a Jaguar XJR-9 seen at the 2018 Le Mans Classic.

Tony Southgate designed the XJR-11 for the 1989 World Sports Prototype Championship. As the TWR-produced V12 engine struggled against the might of the Mercedes engines of the time, Jaguar decided a change was in order. It was decided to use the Rover V64V 3.5 V6 originally designed for the MG Metro 6R4 Group B rally car

Jaguar developed two versions, a 3.0 litre variant for use in the American IMSA championship and a 3.5 litre variant for the World Sports Car Championship. Both engines were fitted with two Garrett turbochargers generating 659 and 750 bhp. Jan Lammers and Patrick Debuted the car at the 1989 World Sports Car race at Brands Hatch finishing 6th. Jaguar managed just a single victory during the 1990 season due to reliability issues. In contrast the XJR-11 was one of the most unsuccessful prototypes produces by Tom Walkinshaw Racing.

Jaguar’s final outing in the World Sports Car Championship was the XJR-12, developed for the 1990 season. The XJR-12 was very successful and would go on to win both the Le Mans 24 Hours and the Daytona 24 Hours.

The Jaguar XJR-14 was the answer to the controversial 3.5 litre formula which replaced the Group C category. After just nine years the FIA had decided to ban turbocharged engines in favour of normally aspirated 3.5 liter engines. Due to the fact that only a handful cars were entered in the 3.5 liter formula, Group C cars with very limited performance were allowed to participate in the new C2 category. One of those manufacturers was Jaguar, which produced the brand new XJR-14 designed by Ross Brawn and John Piper.

In the end the XJR-14 was built by Tom Walkinshaw Racing. Fitted with new aerodynamics and a lower curb weight of just 750 kg, the XJR-14 had a much higher cornering speed than front runners from the Group C era. As the earlier twin turbo engine from the XJR-11 was no longer allowed, Jaguar adopted the 3.5 liter Ford HB V8 engine as used in Formula 1. For use under the new regulations this engine was down rated from around 13,000 rpm to 11,500, resulting in slightly less available power from around 700 to 650 hp.

Jaguar built three chassis, 591, 691 and 791 for use in the 1991 World Sportscar Championship. The XJR-14 turned out as a very fast car, outclassing cars such as the Peugeot 905 and the Mercedes-Benz C291. Although Peugeot entered the upgraded 905B, Jaguar managed to secure the manufacturers title with three wins. Jaguar decided not to enter the XJR-14 at Le Mans as they were unsure if the Cosworth HB-engine would last 24 hours. After 1991 Jaguar decided to leave the World Sports Car Championship in favour of the IMSA championship.

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