Featured: Before It Won Le Mans As A Porsche, Jaguar's XJR-14 Was A Group C Champion

Before It Won Le Mans As A Porsche, Jaguar’s XJR-14 Was A Group C Champion

By Jayson Fong
March 13, 2018

When it comes to Group C, the Jaguar XJR-14 takes more fighter jet styling cues than anything else on the grid. More sculptural and lithe compared to its counterparts, its sleek profile and bubble canopy lead to an enormous rear wing hung off the rear to complete its silhouette, and when coupled with the simple but striking Silk Cut livery it stands out even among the icons like the 956 and C9. But it was more than just the fighter jet looks that made the XJR-14 a memorable piece of kit, for beneath the purple body shell is a car full of technical innovations, marked with many ups and downs during its development… and not always as a Jaguar.

A design overseen by Ross Brawn, then constructed and developed by Tom Walkinshaw Racing in 1991 on behalf of Jaguar, the XJR-14 was built to conform to the new 3.5-liter formula put forth by Bernie Ecclestone that was taking its first steps in replacing the aging Group C era that had been the pinnacle of sports car racing since 1982. However, with minimal entries coming forward for the new formula, the 1991 World Sportscar Championship would see the new 3.5-liter cars running side by side with handicapped Group C machines running alongside. 

Visibly different in appearance compared to the older cars, the XJR-14 was designed around a tight naturally aspirated package that would provide maximum downforce and minimal weight (coming it at 750kgs, or 1,653lbs). Using the same approach as he would for Formula 1, Brawn’s influence saw the car designed under a “competitive interpretation of the rulebook,” which would include the second use of a carbon fiber monocoque on a sports car, extensive wind tunnel testing, and a host of experimental aerodynamic solutions to give the car its edge.

Inside, the driver was suitably cocooned into the his space, which featured pop-out windows doubling as doors (one of the creative rulebook interpretations mentioned above), while behind the cockpit sat a Formula 1-derived 3.5-liter V8 HB from Cosworth, which also saw use by the Benetton F1 team albeit in a different state of tune. In the XJR-14, the motor was detuned slightly for endurance, but it still revved to 11,500 and made 650 horsepower doing it—and recall it only weighed a few pounds over 1,650.

For the 1991 WSC season, the XJR-14 lived up to the reputation of the names behind it. With pace that would have seen the car qualifying for races in Formula 1, its success as a Jaguar would reach its peak with the 1991 manufacturer and driver’s championship in World Sports Cars (although it did not race at Le Mans that year, with Jaguar instead opting for the older and proven-reliable XJR-12).

In 1992, the team took the car to compete in IMSA, but without development in its upgrades and suspension for the bumpier circuits in the United States, the XJR-14 would retire without success as the last “Big Cat” Jaguar sports car.

However, all was not lost for the car itself. Although TWR had lost Jaguar’s sponsorship, Mazda in 1992 was in need of a new machine after their famous rotary engine in the 787B was essentially banned from competition. As a result, the spirit of the XJR-14 would finally race at Le Mans as a Mazda MXR-01, and this time with an off-the-shelf 3.5L Judd V10. But the success enjoyed by Jaguar was not to be repeated by Mazda, and without ongoing development the car fell behind the rest of the pack.

After Mazda decided to depart from sports car racing at the end of 1992, TWR still retained a leftover chassis from the Jaguar era. In a joint partnership with Porsche in 1994 (although never officially factory-backed until 1998), the newest development of the XJR-14 (now called the TWR-Porsche WSC-95) featured an open cockpit and a 3.2-liter Porsche twin turbo flat-six. With the intention of racing it at the 24 Hours of Daytona in 1995, a last minute regulation change meant the car didn’t see any action until Le Mans in 1996 under the the new LMP regulations. However, in prototype form with Joest, the XJR-14 would see a double victory at Le mans in 1996 and 1997 before finally being retired in 1998 as a fully sanctioned Porsche.

A story of ups and downs, the XJR-14 has a unique history in racing from a definitive era. Although a story with many successes, the car is strangely left in the shadows by the manufacturers that used it. Never 100% a Jaguar, nor a rotary-engined success for Mazda, nor an official Porsche Le Mans winner, it’s an outsider. However, despite its many variations, it’s the original Jaguar-era XJR-14 that captures my imagination the most, the purest design in its timeline. Now an occasional racer in the historic Group C racing series, I’m glad at least one original car survived the evolution process; the world would be less one incredibly good looking car without it.


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Rubens Florentino
Rubens Florentino
6 years ago

Wow… amazing story. I would never thought that a same chassis would run under 3 different brands, Jaguar, Mazda and Porsche.
And a Jaguar powered by Cosworth Ford? Perhaps because by that time Ford had already taken ownership of Jag… I don’t know.
I always thought the brands racing at the sports prototype were pretty radical about keeping chassis and engines under the same umbrella.

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