Tom Walkinshaw conceived the concept in 1988, following Jaguar's success at Le Mans, enlisting Peter Stevens to develop a road-going version of the XJR-9, originally designated as R-9R. A number of wealthy racing enthusiasts were keen to own such a car and pressed Walkinshaw into manufacturing a 'road going racer'. Original owners included Derek Warwick, Bob Wollek, Vern Schuppan, Matt Aitken, Andy Evans and the Sultan of Brunei.
In order to adapt the XJR-9 for road use, Stevens made a number of modifications to increase space and improve access. "Taking the race car as a base, we widened the cockpit by 75 mm (3.0 in) and raised the roof by 40 mm (1.6 in) to allow more headroom" he said, when interviewed in 1991. "The scale model was ready by Easter 1989, from there we went to clay...which was finished by October (1989). The first prototype was held up by Le Mans preparations but it was ready for Tom (Walkinshaw) to drive when he came back from France in July 1990."
TWR explicitly developed the XJR-15 as a road-going racing car, in the mould of the Jaguar C and D types, the Ford GT40 and the Ferrari 250 GTO. As such, the car complied with British construction and use regulations and could be registered by the owner for road-use in the UK, although with such a limited production run, the car was never type approved.
The car's production was announced in a press release on November 15, 1990 with an official launch at Silverstone early in 1991. XJR-15 was built by Jaguar Sport in Bloxham Oxfordshire (a subsidiary of TWR) England from 1990 to 1992.
At some point during the production run, TWR produced a limited run of more powerful variants designated XJR-15 LM. These cars are thought to feature a 7.4 litre V12 based on the engine featured in the XJR-9 with a power output upwards of 700 bhp (522 kW; 710 PS). Bodywork alterations include a larger rear wing, an additional front splitter with air vents in the middle and an air intake situated on the roof to help with the larger engine.
Very little is known about the LM variant, though there are photos to suggest that at least five cars were produced (three in dark green, one in white and one in the same blue as the standard car). All of them were sold to buyers in Japan.
The mid-engine, rear-wheel drive sports car is powered by a 450 hp (336 kW), naturally aspirated 24-valve V12 engine of 5993 cc, with a Group C bottom-end and Group A top-end. The engine features an advanced electronically managed fuel injection system with a very advanced (for its time) 'fly by wire' throttle. Transmission is via a TWR 6-speed manual, unsynchronized transmission (a 5-speed, synchromesh transmission was also available as an optional extra).
The XJR-15's chassis and bodywork are composed of carbon fibre and Kevlar (XJR-15 was the first road-going car built entirely of Carbon and Kevlar composites, before the McLaren F1 used similar techniques in 1992). It was designed to comply with 1990 Group C regulations, being 480 cm long, 190 cm wide and 110 cm high. At 1,050 kg (2,315 lb), the XJR-15 weighed about the same as a contemporary VW Golf.
Suspension is fully independent, with non-adjustable Bilstein shock absorbers all round. Front suspension is by wide-based wishbones, working push-rods to spring damper units mounted horizontally across the centre of the car. TWR racing practice is also followed at the rear, with vertical coil-springs mounted in units with uprights within the rear wheels, allowing for the maximum possible venturi tunnels. The engine forms a stressed member for the rear-frame. The bottom of the car is completely flat, in line with Group C practice.
Steel disc brakes are fitted, with powerful AP four-pot callipers.
The XJR-15 has a 0–60 mph time of 3.9 seconds and a (gearing limited) top speed of 191 mph (307 km/h).
Although marketed as a racer, the car had been developed as a "road-going-racer" and as such, the ride height was somewhat higher than required to take full advantage of under-body aerodynamics. Additionally, the suspension was softer than would be found on the XJR-9 racer and - in a last-minute deal - Tom Walkinshaw switched tyre suppliers from Goodyear to Bridgestone just before the race series started. When interviewed by Autosport in 2011, Ian Flux recalled: "The worst thing was that Tom had done a deal with Bridgestone. At first, it was going to be on road tyres, but then they changed to slicks and wets. The fronts weren't a problem, but they didn't have moulds for the rears, so used F40 moulds instead. They went off very quickly and it was hard to judge how hard to push."
As Tiff Needell, who road-tested a development car at Silverstone early in 1991, put it: "the result is oversteer". However, once accustomed to the characteristics, he went on: "Through the very tight chicane, the XJR-15 showed excellent change of direction and I was able to pick up power early for the long right hander leading up to Beckett's. This gradually became a long right-hand power slide as my confidence increased." Users of the car as a racer in later years would lower the suspension, fit a larger wing and proper tyres to restore race-car dynamics.
As a road-car, the suspension was more softly set-up and with the right tyres, testers were unanimous in their praise. Ian Kuah, writing in World Sports Cars in 1992: "Considering its racing pedigree, ride quality is pretty good - at low speeds, better than a Ferrari 348...Levels of grip are far beyond those transgressed by any sane man, except perhaps when exiting a tight corner in a low gear when the sheer grunt pushing you through can persuade the huge Bridgestones to relinquish some grip. Seat of the pants feel and communication is terrific and the steering nicely weighted so that smooth inputs are easy. When it comes to stopping, the huge AP Racing brakes - with softer pads for road use - wash off speed with steely determination."
Ron Grable, the racing driver, writing in Motor Trend in May 1992: "As the engine sprang into a muted rumbling idle, it was impossible to keep from grinning. Easing the unsynchronised six-speed into gear, I accelerated onto the straight. Many race cars are diabolical to get moving...not so the Jag, the smooth V-12 pulled cleanly away, nearly as docile as a street-car. On the track, the XJR-15 is a truly wonderful ride, the perfect compromise between racing and street. You can say the savage edge of a pure race car has been softened slightly, or conversely, that it's the best handling street car you can imagine. Being 100% composite, it's so light that every aspect of performance is enhanced. Relatively low spring and roll rates are enough to keep it stable in pitch and roll, as well as deliver a high level of ride compliance. The brakes are phenomenal and the acceleration fierce. And always, there's that V-12, a medley of mechanical noises superimposed over the raucous rise and fall of the exhaust."
The XJR-15 offers little in the way of practicality. Entry to the car, over a wide sill, requires the driver to step onto the driving seat. The gear-lever is mounted on the right-hand side of the driver (all cars are right-hand-drive), while the driver and passenger seat are extremely close together - almost central in the car. There is little in the way of sound insulation, so an in-car head-set system is fitted. There is virtually no storage space. However, considering the purpose for which it was intended, the interior was highly praised in contemporary road reports. Ron Grable again: "Aesthetically, the XJR-15's interior is breathtaking. Expanses of shiny black carbon fibre woven with yellow Kevlar are everywhere, all fitting together with meticulous precision. Instrumentation is detailed and legibly analogue. The shift leaver is less than 3 inches (76 mm) from the small steering wheel, and the motion between gears is almost imperceptible. The reclined seating position provides excellent forward visibility - over the top of the instrument panel you see only racetrack."EngineEngine type: 60° V12 overhead cam, naturally aspirated
Construction: aluminium-alloy block and heads, forged-alloy pistons, nitrided forged EN40B steel crankshaft with Holset harmonic damper, seven main bearings, cast-iron ‘wet’ cylinder liners, Cosworth pistons
Bore x Stroke: 87 mm (3.4 in) x 84mm
Valve Gear: two valves per cylinder operated by single chain-driven overhead camshaft per bank of cylinders
Fuel System: Zytek electronic engine management
Displacement: 5993 cc/ 365.7 in³
Compression ratio: 11.0:1
Max Power: 335.6 kW/ 450.0 bhp @ 6250 rpm
Specific output: 75.09 bhp (56 kW; 76 PS) per litre
Max Torque: 420 lb·ft (570 N·m) @ 4500 rpm
Weight of Engine: 299 kg (659 lb) including clutch and accessories
TransmissionType: TWR 6 speed manual non synchromesh
Gear Ratio 1st: 3.00 :1
Gear Ratio 2nd: 2.13 :1
Gear Ratio 3rd: 1.66 :1
Gear Ratio 4th: 1.38 :1
Gear Ratio 5th: 1.18 :1
Gear Ratio 6th: 0.91 :1
Final drive ratio: 2.90 :1
AP carbon triple-plate clutch
BodyBody/Frame type: carbon fibre
Body/Chassis details: Carbon fibre and Kevlar composite construction monocoque chassis with engine used as rear suspension load bearer; lightweight composite and carbon fibre reinforced body with under-surface adopting ground-effect venturi channels to the rear and regulation flat floor
Coefficient of Drag: 0.30
Weight distribution: 48% front, 52% rear
According to a press release by Jaguar Sport, XJR-15 was built specifically with the 1991 Jaguar Sport Intercontinental Challenge in mind: a three-race competition held throughout the year as support events for the 1991 Formula One Grand Prix at Monaco, Silverstone, and Spa-Francorchamps.
Sixteen XJR-15s were entered in each of the events. The winner of the third and final race, Armin Hahne, was awarded a cash prize of US$1 million.
Having parted with nearly $1m for their cars, most XJR-15 owners wanting to participate in the Intercontinental Challenge got professional drivers to do the racing. Preparation and maintenance by JaguarSport was included in the purchase price. At stake for the winners of the first two rounds were a pair of Jaguar XJR-S road cars whilst at the Spa finale there was a $1m winner-takes-all prize fund.
A maximum of 16 grid slots were available for each event and all three were fully subscribed. Derek Warwick emerged top of the timesheets in qualifying followed by Armin Hahne, Jim Richards, David Brabham and Davy Jones. Rounding out the top ten were Bob Wollek, Tiff Needell, John Nielsen, Ian Flux and Juan Manuel Fangio II.
Each race kicked off with a rolling start administered by Tom Walkinshaw and the charge into Ste Devote saw Warwick and Hahne touch several times before Warwick emerged in front. On lap two, John Nielsen ran wide at Tabac and thumped the barriers on both sides of the track before Hahne lost it entering the swimming pool on lap three, luckily emerging unscathed. This allowed Warwick to open up a four-second gap from Brabham, Jones and Fangio before losing it all after locking up into the swimming oool. The Englishman eventually finished seven tenths of a second ahead of Brabham after 16 laps hard racing.
With the first race having enthralled the crowd yet passed without major incident, hopes were high for another great spectacle at Silverstone. Warwick again started from pole with Brabham, Cor Euser, Ian Flux, and Wollek in fifth. Fangio, David Leslie, Hahne, Kenny Acheson and Needell also qualified in the top ten. The rolling start saw five abreast into the first corner but the opening lap passed with all 16 cars intact. On the second lap Nielsen and Jones engaged in some panel bashing at Becketts whilst at Stowe, second placed Warwick turned in on leader Euser. Warwick took the position, Euser spun (dropping to third) but Warwick’s lead was short lived as he picked up a puncture, lost control and hit Brabham when making a pass.
Both men went into the pits for repairs. This left Euser back in the lead but his bonnet was gradually working loose which forced him to miss the apex at Beckets resulting in a spectacular 120 mph (190 km/h) spin. Now Flux was in the lead followed by Fangio and Hahne. By lap six Euser’s charge back to contention suffered another setback when he hit David Leslie at Priory, both cars spinning as a result. Two corners later, Needell bumped Hahne out of the way to take third. Lap nine finally saw an end to Euser’s afternoon when he hit Acheson and ended up beached in the gravel. Acheson was forced to pit. Competing for third, Needell and Hahne had another coming together forcing both cars out of contention. At the front, Fangio took the lead when Flux missed a gear at Club and dropped to second ahead of Wollek and Win Percy. Wollek’s tyres were still in great condition having driven steadily throughout and the American was able to reel in Flux, passing on lap 18. Fittingly, the race was won by Fangio precisely 45 years after his famous uncle’s last win at Silverstone. At the end of the race, 11 of the 16 entries had suffered some kind of damage.
The final Intercontinental Challenge race at Spa was a big deal. With $1m on the line for the winner, there had been much speculation about race fixing agreements between the drivers. To counter, JaguarSport decided the race would run for an undisclosed number of laps. All the drivers knew was that the chequered flag would fall after at least six laps.
Qualifying saw Euser on pole followed by Brabham, Warwick, Hahne, Percy, Will Hoy, Wollek, Leslie, Thierry Tassin and Flux all in the top ten. However, only fourth place Hahne and newcomer Tassin had saved a spare set of fresh tyres for race day. The rolling start went off without a hitch until Brabham had a big moment at the top of Eau Rouge dropping from second to seventh in the process. This left Euser, Hahne and Warwick to open up a gap at the front, the three drivers pacing themselves for the opening stint. There was plenty of action going on behind though, John Watson losing it at the end of the main straight, flying off the track backwards at 140 mph (230 km/h) and collecting Needell in the process.
On the next lap, Tassin and Percy had a coming together at the bus stop, Tassin ending up atop the barriers after a heavy impact. After six laps were up, the racing became more fraught at the front. Now up to second, Hahne seized the initiative when Euser went offline through Eau Rouge on the eighth lap. Hahne’s momentum took him through down the main straight and third place Warwick had eyes on second but dicing with Euser allowed Hahne to get away. Warwick then lost it at the sequnce of corners before the bus stop, pin balling off the barriers and into retirement. From thereon in it was Hahne all the way and when the chequered flag fell at the end of lap 11, the $1m prize was secure.
When interviewed by Autosport in February 2012 for 'Race of Your Life', Armin Hahne chose his XJR-15 win at Spa as career-highlight: "I qualified second to Warwick in Monaco but half-spun on oil while chasing him, so fell to fifth. At Silverstone I had a misfire and again finished fifth. At Spa, I managed to qualify second without using both sets of new Bridgestone slicks. I found a time good enough for the front row with my 'scrubbed' first set. At the start, I followed poleman Cor Euser for a few laps, but his tyres went off as he'd used them for the second qualifying session. I passed him - it was quite easy really. The race lasted 11 laps and I won by 3-4 seconds to collect the $1m prize."
Monaco 16 laps x 3,328 = 53.248 km
Silverstone 20 laps x 5,226 = 104.52 km
Spa Francorchamps 11 laps x 6,94 = 76,34 km
After Jaguar withdrew from sportscar racing in 1994, Nissan approached TWR to develop the R390 race car. TWR used the middle-section of the XJR-15's tub - the cockpit and greenhouse - for the R390, however the R390 used revised rear and front ends, a wider overall chassis, and a different suspension for better handling, as well as a new exterior design, and - obviously - a Nissan rather than a Jaguar engine. All four R390s finished in the top 10 at the 1998 Le Mans, in 3rd, 5th, 6th and 10th.
On the 6th of June 1999, the Aston Martin Owners Club ran the first ever Historic 'Group C' invitation race at Donington in the UK. Bryan Wingfield entered an XJR-15 (number 7, originally driven by Cor Euser in the Jaguar Intercontinental Challenge), driven by Tommy Erdos, finishing 4th overall and first in class.
The original very high price of the XJR-15 meant that the majority entered private collections and were never driven. Vijay Mallya, Lindsay Fox, Matt Aitken, Andy Evans, Derek Warwick and the Sultan of Brunei, amongst others, each owned (or now own) an XJR-15 as part of a large collection. Cars released from collections, often with very low mileage but in need of re-commissioning, occasionally come up for auction. Known results are shown in the table below with prices in original currency and conversion to GBP at Sept 2012 rates.
The car features in the 1998 video game Need for Speed III: Hot Pursuit, published by Electronic Arts. The car is the only Jaguar to make an appearance besides the Jaguar XKR.
It also made its first, and so far, only appearance in the Gran Turismo franchise in Gran Turismo 2. Its official name in the game is Jaguar XJR15 GT Race Car, and could be purchased in the special vehicles list in the Jaguar dealership.
In Cars 2, Holley Shiftwell resembles a Jaguar XJR-15