This is an old revision of this page, as edited by Fuzzyworcester (talk | contribs) at 20:20, 27 May 2007. The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.
Revision as of 20:20, 27 May 2007 by Fuzzyworcester (talk | contribs)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)The Jaguar XJR-14 was a Sports-prototype racing car introduced for the 1991 World Sportscar Championship season. The 1991 season marked the introduction of the FIA’s new 3.5 litre formula, which replaced the highly successful Group C category that had been used in the World Sportscar Championship since 1982.
To meet the new regulations Jaguar came up with an all-new car; the XJR-14 which was designed by John Piper under the design direction of Ross Brawn and built by Tom Walkinshaw Racing (TWR). Brawn brought with him Formula One design methodology. In the past, TWR's Jaguars had been designed under the direction of Tony Southgate, while Brawn worked with a large design staff (12 according to John Piper). The primary feature of the new regulations was the use of a 3.5 litre naturally-aspirated engine. This made it impossible for Jaguar to use the engines from it’s previous Group C cars – even the 3.5 litre V6 from the XJR-11 was turbocharged. Also, to produce similar power to the Group C cars any 3.5 litre naturally-aspirated engine had to be very high-revving and be constructed from different materials in order to rev highly.
Fortunately, Jaguar’s owners were Ford who also supplied 3.5 litre naturally-aspirated engines to Formula One teams of that era, and most notably the Benetton team. The engine regulations for the new 3.5 litre formula were identical to Formula One so TWR were able to use the Ford HB V8 engine from the Bennetton B190B Formula One car. Detuned to about 11,500 rpm (compared to about 13,000 rpm) and producing slightly less power (about 650 bhp compared to around 700 Bhp) Jaguar effectively had a race-proven engine.
Design wise the XJR-14 looked unlike any other previous sports-prototype, primarily because the redesign of the Le Mans circuit in 1990 meant that the low drag, top-end power, straight-line acceleration and top-speed characteristics of previous sports-prototypes was no longer required. The car now focussed more on downforce and featured a full width double-decker rear wing and a front wing between the lights, making the car have a lower top speed than Group C cars and, as a result of the chasteristics of the 3.5 litre engine, less accelerative above 150-170 Mph. However, the lower kerb weight of 750 Kg and the increased downforce meant that the XJR-14 was a lot faster in corners. The overall effect of the new design meant that the XJR-14 was as fast as a contemporary Formula One car around circuits used by the Grand Prix fraternity.
In the 1991 World Sportscar Championship season, the XJR-14 had a hard fight with the new and quickly improving Peugeot squad, but was able to gain three wins on the season, securing a world championship. However, at the 1991 24 Hours of Le Mans, Jaguar initially entered two XJR-14s but later decided that the XJR-14 would not be capable of finishing the distance due to unknowns in the development of the Cosworth HB. Jaguar instead decided to enter three older XJR-12s entered in the C2 class. Although the XJR-12s did not manage to win, Jaguar's decision not to run the untested XJR-14 was vindicated by the fact that neither Peugeot's nor Sauber-Mercedes' 3.5 liter cars finished.
After 1991, Jaguar decided not to continue in Group C, believing that they had spent enough time in Group C and the instability of rules recently in the World Sportscar Championship. Jaguar decided to take the XJR-14 to the United States for the IMSA Camel GTP championship. However, without a major upgrade, the XJR-14 was unable to beat the latest challengers from Toyota and Nissan, forced to finish third in the championship with only two victories. Jaguar had to go through three chassis in the series after two, #591 and #791, were written off in separate accidents.
Meanwhile, TWR had reached an agreement to supply more XJR-14 chassis to Mazda, minus the Cosworth V8s but installed with Mazda-badged Judd V10s for the World Sportscar Championship. Mazda would rebadge the XJR-14s as MXR-01s. The MXR-01 was essentially a productionsed XJR-14 and as there had been no ongoing development they ended up not being particularly competitive, scoring no wins and finishing third in the championship.
Several years later, TWR would resurrect XJR-14 chassis #691, which had competed in IMSA Camel GTP, for the development of a new prototype for Porsche. The car would be renamed the TWR WSC-95, and its most significant feature was that it had it's roof removed to turn the car into an open cockpit prototype to run under the then-new LMP regulations. The WSC-95 would carry a Porsche 3.0L turbocharged Flat-6. After chassis #691 was modified, TWR built a second WSC-95 from scratch. In both the 1996 and 1997 24 Hours of Le Mans, the TWR-Porsches were able to take the overall win. Former XJR-14 chassis #691 would eventually end up in the Joest museum, the team which took the WSC-95 to victory in both years.