“With the XFR we have a very credible, competitive platform with which to work. What we have given the XFR-S is greater handling capacity, greater precision and greater capability. It’s a car for driving purists – it will feel engaging within the first 50 metres but remains accessible and confidence-inspiring at any speed.”
Mike Cross, Chief Engineer, Vehicle Integrity, Jaguar
The dynamic characteristics of the XFR-S were informed by the engineering development of both the XKR-S and the F-TYPE, the result being an incredibly agile, responsive and involving super saloon.
Both front and rear suspension systems have been uprated and carefully tuned over tens of thousands of miles at Jaguar’s testing centre at the legendary Nürburgring, the high-speed bowl at Nardo in Italy and, of course, the engineers’ favourite roads around the Gaydon Research and Development centre and in north Wales.
Overall lateral suspension stiffness has been increased by 30 per cent front and rear, with front and rear spring rates increased by the same amount.
Front suspension knuckles have been revised in line with those found on the XKR-S to achieve the increased camber and castor stiffness which, along with new wheel bearings, optimise steering and handling precision. The steering system has additionally benefited from the fitment of the valving developed for the F-TYPE.
At the rear a new subframe has enabled revisions to suspension geometry which, allied to stiffer bushes – new rear knuckles and working in tandem with the stiffer springs – increase stability and response.
In order to achieve the maximum benefit from the suspension revisions, the XFR-S has new lightweight, forged 20-inch ‘Varuna’ alloy wheels. These are half an inch wider at the front and an inch wider at the rear in comparison to the wheels found on the XFR but their construction means there is no weight penalty to be paid.
The tyres, developed in conjunction with Pirelli exclusively for the XFR-S, are 10mm wider all round, being 265/35 and 295/30 front/rear. The difference between the wheel rim and tyre width increases has the effect of pre-loading the sidewall to improve handling and steering response without adversely affecting refinement.
Working in harmony with the uprated suspension, wheels and tyres are revised electronic programmes controlling the Adaptive Dynamics, active electronic differential and Dynamic Stability Control systems.
Jaguar’s Adaptive Dynamics system actively controls vertical body movement, roll and pitch rates through the use of continuously variable dampers. The system monitors driver inputs and the road conditions, adjusting damper rates in response up to 500 times a second to optimise stability and agility. The driver’s selection of Dynamic Mode offers enhanced body control through moving the damping rates to the firmer end of the available range.
The Jaguar active electronic differential – which can apply full locking torque almost instantaneously when necessary – has been recalibrated in order to exploit the greater grip offered by the wider rear tyres, the more precisely controlled suspension and the engine output. Working in parallel with the differential, the ‘Trac DSC’ setting of the Dynamic Stability
Control system now offers the enthusiastic driver more opportunity to explore the outer edges of the handling envelope while nevertheless providing a discreet safety net.
Providing equal levels of confidence is Jaguar’s High Performance Braking System which offers an unmatched combination of power, stability and fine modulation. The 380mm front and 376mm rear discs are internally ventilated for assured repeated stopping power and on XFR-S benefit from additional cooling provided by under-body air channeling.
