2003 Jaguar XJR

Overview

The 2003 model year XK benefits from a broad programme of improvements -there are some 900 part number changes - underlining the fact that while its appeal may be timeless, development of this sporting Jaguar has certainly not stood still. Now with a full 400bhp (DIN), the XKR is now even more impressive than the car that has earned the model its reputation. In fact, the 400bhp XKR shares with the latest S-TYPE R sports saloon the distinction of having the most powerful series production engine in Jaguar 's history.

The package of advances over the previous generation XK also encompasses the latest electronic driving aids. Covering areas from handling and braking to 'intelligent 'cruise control, these include Dynamic Stability Control and Emergency Brake Assist as standard across the XK range, and Jaguar's innovative, traffic-sensing ACC (Adaptive Cruise Control) as an option.

The latest R Performance range of options (available on both XK8 and XKR) includes unique Recaro seats, high performance Brembo brakes (now standard on the XKR)and a package of interior details with sporty aluminium or leather finishes. A handling package that uprates suspension and steering is available on coupe models only.

Engine

The adoption of all-new powertrains is the biggest change in the new-generation XK. The latest 4.2-litre AJ34 version of Jaguar's outstanding AJ-V8 engine is

coupled to an industry-leading six-speed automatic transmission. (posted on conceptcarz.com) Driving through a rear axle with a new differential that is fine-tuned to maximise the power and torque characteristics of the new engine, the result is an exceptional powertrain. Both engine and transmission are very similar to those recently introduced in the S-TYPE range, but have been specifically engineered for use in the XK.

The new 4.2-litre V8 benefits from continuously Variable Camshaft Phasing. A hydraulic actuator on each inlet camshaft is operated by a pair of electronically-switched oil-pressure control valves, activated by the engine control module - which contains maps of engine speeds and loads. The system continuously adjusts the phasing of the camshafts, from maximum advance to maximum retard in less than 0.7 seconds. The inlet timing is therefore optimized at all times, according to load and other conditions, to produce faster engine response and optimum performance at all engine speeds -with more torque at low speeds and maximum power at high speeds.

To match the increased output and the increased mechanical and thermal stresses that supercharging imposes, the new XKR V8 has stronger pistons, forged from single billets of aluminium alloy. It also features oil jet cooling on the underside of the piston crowns, for maximum cooling and minimum distortion.

Transmission

The transmission is not a Continuously Variable Transmission (CVT) with six intermediate steps, rather it is a traditional automatic transmission with six ratios. With 'Mechatronic' shift control providing an adaptive shift strategy that responds both to road conditions and the way the car is being driven, the transmission gives the smoothest possible shifts and optimum performance. This is complemented by changes to the final drive to match the increased power of the new engine, and a revised version of Jaguar's 'J-Gate 'selector, which has a smoother shift action. The transmission gives improved performance with better economy, is lighter, more compact and mechanically simpler than the five-speed automatic it replaces, and requires minimum maintenance for life.

Brakes

The 2003 XKR now has Brembo brakes as standard. The system features 355x32mm ventilated front discs and 330x28mm ventilated rear discs, with four-piston aluminium calipers carrying the Jaguar R Performance logo. Steel-braided brake lines complete the highly impressive specification and give the XKR stopping power and feel more than equal to its exceptional performance. The Brembo braking set-up is available as a cost option on XK8, linked to one of the three 20-inch R Performance styles available.

Electronic Driving Aids

A car with the power and performance potential of the new-generation Jaguar XK deserves the best in mechanical and electronic driver safety aids - and this car gets them. Features including Dynamic Stability Control (DSC), Emergency Brake Assist (EBA), and Jaguar 's Computer Active Technology Suspension (CATS) system are all standard (CATS optional on XK8).Also standard on every new-generation XK model is Jaguar 's Adaptive Restraint Technology System (A.R.T.S.), which is universally acknowledged as a major advance in passive vehicle safety.

Source - Jaguar Media