- - Thursday, August 4, 2011

Simply put, XKR-S is the most extreme expression yet of Jaguar’s passion for building beautiful, fast cars. For the first time with a series production car, Jaguar gains entry to the exclusive ‘300kph club’ (186mph) thanks to the effortless performance of the supercharged 5.0-litre AJ-V8 engine. A revised fueling map means the direct-injection powerplant now produces 550hp and 502 lb/ft of torque. Extensive tuning has ensured that power delivery and performance are seamless, contributing to a 0-60mph time of 4.2 seconds. The active exhaust encourages and rewards the enthusiastic driver with dramatic, motorsport-inspired aural feedback.

The pinnacle of the XK range builds on experience gathered from the supercharged XKR and has been developed to extend the performance parameters of the car. This new sharper-edged character allows the enthusiastic driver to explore the limits of the car’s dynamics without losing the refinement for which Jaguar is famous. The structural rigidity of the lightweight aluminum platform allowed the suspension to be reworked with bespoke components for increased stiffness without a commensurate loss of refinement. A reworked aluminum front suspension knuckle and revised rear geometry are allied to stiffer springs and dampers, lightweight forged alloy wheels and recalibrated steering effort provide immediate response and produce a more connected and agile driving experience.

The performance of the XKR-S is reflected in both its interior and exterior styling, which feature exclusive new paint colors that reflect Jaguar’s racing heritage. As with competition Jaguar cars of the past, the exterior of the XKR-S adheres to the principle of form following function. In addition to the styling changes, the XKR-S was the subject of extensive Computational Fluid Dynamics development work in order for it to achieve 186mph. The resultant changes reduce front and rear lift and optimizes lateral aerodynamic stability.

The performance intent of the XKR-S is clear from the moment the driver enters the cabin thanks to new cosseting Performance seats with prominent shoulder bolsters for close support during hard cornering. The seats feature 16-way adjustment, with memory and heating functions. A new three-spoke steering wheel provides the perfect interface between car and driver.

Ian Callum, Design Director, Jaguar Cars, “The styling of this car isn’t about image, it’s about true performance. Like other iconic Jaguar cars before it, the styling has been driven by geometry and aerodynamics for genuine design purity.”

The first Jaguar designed entirely under the guidance of Design Director Ian Callum, the XK has received accolades worldwide for its arresting appearance. Now further styling changes keep the XKR-S at the forefront of modern sports car design. Slimmer LED headlights, more compact main air intake and vertical side power vent all contribute to a more purposeful frontend appearance. At the rear of the car, the famous Jaguar ‘Leaper’ now proudly takes its’ place in the center of the decklid.

The XKR-S also required aerodynamic modifications to achieve its 186mph top speed in the unruffled manner expected of a Jaguar. It has been designed solely with an eye for purity of line and singularity of purpose. As the XKR-S approaches its top speed, there is a requirement to channel air cleanly over, around and under the car in order to maintain stability and ensure balanced down force front and rear. An overall reduction in lift of 26 percent has been achieved.

The necessary revisions were made after extensive Computational Fluid Dynamics work, proven through wind tunnel testing and are unique to this flagship of the XK range. The most dramatic changes have been applied to the front of the car, radically altering its appearance and lending it a more assertive look. A new bumper design features near vertical feature lines running down from the edges of the oval air intake and supporting the new carbon-fiber splitter and lower spoiler. At the extreme edges of the front fenders, vertical slots channel air down the sides of the car and along the wider sills for increased high-speed directional stability.

In order to balance front and rear lift, the XKR-S features a separate rear wing, a first for the XK range. This addition, with its carbon-fiber center section, works in concert with the similarly constructed venturi effect structure underneath the rear bumper.

The assertive new appearance of the XKR-S is subtly highlighted by some carefully chosen details exclusive to this model. Exterior trim is finished in gloss black, complemented by 20-inch Vulcan lightweight forged alloys in a dark finish.

The XKR-S is available in five paint colors, two of which evoke Jaguar’s competition heritage: Italian Racing Red and French Racing Blue.

Like the lining of a bespoke suit, the finishing touch is provided by the brake calipers, available in either red or gunmetal and emblazoned with the ‘Jaguar’ name.

Russ Varney, Chief Program Engineer, XK, “With the XKR-S we have exploited the inherent capabilities of the aluminum architecture to its fullest extent to create a track-capable performance derivative, extending all cars’ attributes and, we expect, eliciting an irresistible ‘smile of satisfaction’ response from the driver.”

Astonishing engines have always formed the strongly beating heart of Jaguar’s road and race cars from the record-setting straight-six in the XK120 to the smooth V12 that made the XJ12 the fastest four-door in the world when it was launched.

The AJ-V8 joined this illustrious list from the moment the first one was fired into life but in the XKR-S it is presented in its most potent form to date. Now in its third iteration and with the addition of supercharging, the all-aluminum four-cam powerplant delivers not only extreme performance but also improved efficiency thanks to the technologies incorporated into it, including spray-guided direct injection (SGDI) and dual independent variable cam timing (DIVCT).

Fuel is delivered directly to the center of the combustion chambers at over 2000 psi by the centrally-mounted six-hole spray-guided injection system in order to maximize fuel-air mixing and improve responsiveness, particularly at low speeds. It has also allowed an increase in compression ratio from 9.1:1 to 9.5:1.

Each of the four camshafts features a variable timing system which is activated by the positive and negative torques generated by the movement of the intake and exhaust valves rather than being controlled by oil pressure. This design allows for a smaller, more efficient oil pump to be fitted, reducing fuel consumption. The VCT units respond up to three times faster than previously with actuation rates of more than 150 degrees per second at every point in the RPM range.

Like the car itself, the AJ-V8 features aluminum architecture with the high pressure die-cast lightweight block with cast iron liners and cross-bolted main bearing caps. The four-valve cylinder heads are now constructed using recycled aluminum to reduce the environmental impact of engine manufacture.

Nestling in the ‘V’ of the cylinders is a Roots-type twin vortex supercharger and two intercoolers that help provide the XKR-S with such urgent motive power. This sixth-generation forced induction unit is 20 percent more thermodynamically efficient than its predecessor, while the intercoolers feature their own water-cooling circuit to reduce the temperature of the pressurized air to optimize power and efficiency.

Remapping the engine’s fueling characteristics and increasing exhaust gas flow through the use of an active exhaust system has lifted total output of the 5.0-liter V8 to 550hp* and 502 lb/ft. making it the most powerful Jaguar road engine ever made. This powerplant allows the XKR-S to hit 60mph in 4.2 seconds and touch the magical 300kph (186mph) barrier with ease.

The Performance active exhaust system that helps provide such spirited performance also produces a thrilling motorsport-inspired soundtrack to aurally reward the enthusiastic driver.

Mike Cross, Chief Engineer, Vehicle Integrity, “This car encompasses everything a performance Jaguar should be; as capable, precise and thrilling on a wet Welsh B-road as it is at the Nurburgring. Every response delay has been minimized in order to give the car a more connected feel in the manner in which it steers, handles, stops and goes.”

Jaguar pioneered the use of aluminum construction for production cars, exploiting the metal’s low mass and high tensile strength to optimize benefits in terms of performance, agility, fuel consumption, and emissions.

The aluminum platform underpinning the XK range makes the car light and rigid. This fundamental strength allowed Jaguar’s Vehicle Integrity team, led by Mike Cross, to develop the dynamic attributes of the XKR-S to the full, without affecting refinement. Every Jaguar achieves an unrivalled mix of sporting appeal and luxurious comfort and the XKR-S is the most driver focused Jaguar ever made.

Taking the solid foundation of the aluminum architecture as a starting point, both front and rear suspensions have been upgraded. The double wishbone front suspension has been comprehensively revised with a new aluminum steering knuckle that significantly increases camber and castor stiffness; to transform the accuracy and weighting of the steering for greater levels of connection, feedback and precision. The Active Differential Control has been reprogrammed to reduce steering sensitivity at the very high speeds of which the car is capable, increasing stability and driver control.

Rear suspension geometry has been revised with rear wheel steer while spring rates have been increased at both ends of the car by 28 percent. Bespoke software for Jaguar’s Adaptive Damping has been written for the XKR-S, ensuring both total body control and maximum traction and grip.

Wheel sizes have been increased with lightweight forged “Vulcan” 20-inch alloys. The wheels are now nine inches wide at the front and 10.5-inches at the rear for greater precision and grip. The new wheels wear Pirelli PZero tires measuring 255/35 R20 at the front, 295/35 R20 at the rear. This combination has reduced overall unsprung mass by over 10 pounds, with a commensurate improvement in handling and response.

The Dynamic Stability Control System has been reworked to optimize the benefit of these wider tires. The “Trac DSC” mode utilizes specific traction, stability and eDiff settings to alter slip thresholds, differential torque distribution, and intervention levels to allow the experienced driver to explore the upper limits of the performance and handling envelope.

The end result is a car that captures the essential duality that is a characteristic of every great Jaguar; capable of transporting the driver to the fabled Nurburgring in total comfort and hushed silence, deliver a sub-eight minute lap time on the track, and return home with total ease.

The cabin of any Jaguar is a special place to spend time. The driver is greeted by the red Start button pulsing like a heartbeat. When pressed, the engine fires to life with a rich, deep reverberation. The Jaguar Drive Selector rises from the center console as a point of first contact, initiating the bond between driver and automobile.

The interior of the XKR-S has been subtly refreshed with a host of new trim materials including ebony soft-feel paint for the switches and gloss black finish to the center console.

The model will also be exclusively available with a Dark Linear Aluminum finish as an option to the wood veneers.

A new leather-wrapped, multi-function steering wheel has also been added along with

Jaguar-embossed stainless steel pedals to provide a beautiful, tactile interface between car and driver.

Exclusive to the XKR-S are the new Performance front seats with integrated head restraints and increased lateral support to hold driver and passenger securely and comfortably in place during the high speed cornering. The 16-way adjustment of the seat is supplemented by memory and heating functions.

The sense of occasion offered behind the wheel of the XKR-S will be heightened by the new

carbon leather accents covering the seats, featuring contrast micro-piping and stitching

combinations in Reims Blue, Red and Ivory. Duotone combinations of Charcoal with Tan and

Charcoal with Red are also available.

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