15/11/12

Overview: Jaguar F-Type

The new F-Type is a front-engined, rear-driven two-seater built around the fourth generation of Jaguar’s lightweight aluminium architecture. Torsional and lateral stiffness were a priority for the designers. Wheel location front and rear is by aluminium double wishbones. Three engines are offered; all drive through ZF’s excellent eight-speed automatic transmission, specified with a close set of ratios, and all bar the least powerful feature driving mode selection and a limited slip differential. The V6-powered S model also includes a Dynamic Launch feature, which optimises acceleration from rest.

All three engines are supercharged. Two use 340PS and 380PS versions of a new V6, while the most expensive model is powered by a 495PS version the Company’s familiar V8. All engines feature a stop-start system.

The new three-litre V6 power unit is derived from the five-litre V8. The 340PS and 380PS variants power the F-Type and F-Type S respectively. The V8 which powers the F-Type V8 S is a newly-developed version of the existing engine; its torque output of 625Nm offers the promise of substantial mid-range acceleration.

An ‘active’ exhaust system is standard on the S and V8 S models and is described by Jaguar as adding ‘another dimension of driver-engagement’. Valves in the exhaust system open under load from 3000rpm, tailoring the exhaust note to the ego of the driver.

Exclusive to the F-Type S is a 380PS and 460Nm version of the three-litre V6 supercharged engine that was introduced to the 2013 model year XJ and XF saloons in 340PS and 450Nm form; that 340PS engine also being offered in the F-Type. Based on the five-litre V8 engine, now in its third generation, the V6 shares the bigger engine’s all-alloy construction, with the lightweight die-cast block stiffened with cross-bolted main bearing caps.

The four-valve cylinder heads are constructed from recycled aluminium, with the valves themselves controlled by a dual independent variable cam timing system activated by the positive and negative torques generated by the movement of the intake and exhaust valves. The actuation rates are more than 150°/s.

Spray-guided direct fuelling is used. This delivers fuel directly into the centre of the combustion chambers at pressures of up to 15MPa. The compression ratio is also raised from 9.5:1 in the supercharged V8 to 10.5:1.

Mounted in the V of the engine is the latest-generation Roots-type twin vortex supercharger. The use of supercharging avoids pumping losses caused by increased back pressure in larger capacity turbocharged engines, although it does of course introduce a parasitic load of its own. It is more compact than the supercharger used with the V8, and uses an air-coolant intercooler.

The supercharger boost is controlled by new Bosch engine management software.

In its 380PS state of tune, the V6 produces the greatest specific power output of any Jaguar engine to date: 127PS/l. In the F-Type S that results in a 0-100km/h sprint time of 4.9s and an electronically-limited maximum speed of 275km/h (171mph). The F-Type and F-Type S achieve CO2 emissions figures of 209g/km and 213g/km respectively on the rolling road.

The V8 S is powered by a new variant of Jaguar’s supercharged five litre engine tuned to provide 495PS and 625Nm. The sprint to 100kmph is covered in a claimed 4.3s with an electronically limited top speed of 300km/h or 180mph. Over the NEDC driving cycle, CO2 emissions are 259g/km.

Structure

Jaguar’s goals for the F-Type were low mass and an extremely rigid body. Key to this was the further development of Jaguar’s alloy technology. AC300, a crash-crush 6000-series alloy was refined specifically for the F-Type application to provide levels of strength comparable to the existing high-performance XK platform — for which it was first developed — while offering a considerable reduction in mass.

As a result the F-Type body-in-white weighs just 261kg. Concentrating more of the mass within the wheelbase by minimising the front and rear overhangs also provides the car with a low polar moment of inertia. The F-Type’s driving position is 20mm lower than the XKR-S’s, dropping the centre of gravity.

In addition to the structural alloy, Jaguar further developed a skin panel alloy in order to deliver the desired design. This AC600 alloy offers the same robustness and quality of finish as the existing metal used on the XK but with much greater formability to provide greater clarity and tightness of radii. This allowed, for example, a reduction in radius of more than 50 per cent., down to just 8mm, to allow the engineers to reproduce the styling ‘heartlines’ exactly as the designers had intended. The clamshell bonnet, an exotic signature feature of the car and where the front heartline begins, is a one-piece stamping, made using a 1000-tonne press.

Weight savings have been achieved in a number of key areas, using a number of different techniques. For example, the alloy front subframe saves 5kg compared to a steel equivalent. The F-Type also has more composite materials than in any previous Jaguar, with crash-management structures under the sill and the boot lid constructed from high-strength plastics.

Aluminium forms a great part of Jaguar’s corporate commitment to sustainability, with more than half the content of the car coming from recycled metal. In addition, the F-Type’s structure is exclusively riveted and bonded — this manufacturing process emits up to 80 per cent. less CO2 compared to welding a comparable steel structure. Jaguar is also rolling out its closed-loop recycling system to its suppliers, ensuring all offcuts of metal from the manufacturing process are reused.

Eight-speed ‘Quickshift’ transmission

ZF’s 8HP transmission has been set up for the F-Type with closely-spaced ratios. The torqure converter’s lock-up clutch works in every forward gear apart from first.

We have always been very impressed by the speed and smoothness of this transmission’’s gearchanges, though Jaguar makes what seems to be a claim to having made the box more ’thumpy’ for the F-Type. We shall see.

The operating parameters of the transmission are determined by the adaptive shift strategy which has 25 different programs available to it, depending on driving style and road conditions. The transmission can detect the manner in which the car is being driven by monitoring acceleration and braking, cornering forces, throttle and brake pedal activity, road load, kickdown request and whether the car is being driven up or down hill. On detecting a more urgent driving style, the transmission will automatically make the gearshifts more aggressive and move the shift-up point to higher in the rev range.

The transmission also features a number of functions that specifically relate to the enthusiastic manner in which the F-TYPE will be driven. In order to keep the car balanced during a downshift, the transmission will instruct the engine management system to blip the throttle to match engine revs. This function also allows the transmission to perform multiple and very rapid downshifts during hard braking.

Corner Recognition senses when the car is negotiating a bend, the transmission holding its ratio to ensure the correct gear for the exit. The transmission will also recognise when the car is performing a series of overtaking manoeuvres requiring rapid changes in throttle position and, rather than change up, remain in a lower gear ready for the next demand for acceleration.

Manual override of the transmission is available to the driver at any time, using either the steering wheel-mounted paddles or the central shift selector. Moving the selector to the left accesses manual mode in which pushing the lever forward selects a lower gear and pulling it back instructs an upshift. If Dynamic Mode is also selected on the Jaguar Drive Controller, the transmission will not automatically shift up at the redline and will only downshift to prevent engine stalling, leaving control fully in the hands of the driver.

The F-Type S offers one additional feature to optimise acceleration from rest: Dynamic Launch Mode. When the car is stationary, the driver depresses the brake pedal while simultaneously building engine speed until a message reading ‘Dynamic Launch Ready’ appears in the instrument panel. The driver then simply has to release the brake pedal while flooring the throttle and the car will do the rest, optimising acceleration.

A mechanical limited-slip differential is fitted as standard to the F-Type S. The mechanical system was chosen for its ‘authenticity’ (?) and suitability for a rear-wheel drive sports car, offering the driver the opportunity to explore the car’s balance and the outer limits of its grip ‘within a progressive and tactile handling envelope’. The V8 S model is fitted with Jaguar’s active electronic differential to limit wheelspin, maximise traction and offer even greater control. The Jaguar active differential is operated by an electric motor acting on a multiplate clutch which can transfer torque to the wheel with the most grip. Fully automatic in operation, the system can apply full locking torque almost instantaneously. Working in conjunction with the stability, traction and ABS systems, it allows for very fine control of power delivery and always makes the most use of available grip.

Braking

The Jaguar Performance system fitted to the 340PS F-Type has 355mm front and 326mm rear brake discs with silver coloured calipers. The F-Type S gets the Jaguar High Performance system gaining larger 380mm brake discs at the front with black or red painted calipers. The F-Type V8 S uses the Super High Performance system with the largest set of brake discs fitted as standard to a Jaguar production car: 380mm front 376mm rear, with black or red painted calipers. All cars are fitted as standard with ABS, Electronic Brake Force Distribution and Emergency Brake Assist.

The use of computational fluid dynamics allowed Jaguar to optimise brake cooling, with cold air channelled to the brake discs by way of the air intakes flanking the grille and by the use of aerodynamically shaped suspension components to direct airflow beneath the car.

The F-Type is also fitted as standard with Jaguar’s ‘intelligent’ stop-start system, which unfortunately requires the driver to keep his foot on the brake pedal. If he engages the parking brake and releases the brake pedal, the engine will start again — not ideal for motorists who actually drive properly.

The speed of operation of the twin solenoid system also allows for ‘change of mind’ functionality, bringing the engine back up to speed even during its run-down phase if, for instance, the car is coming to a halt at a junction when the driver sees an opportunity to join the traffic flow. The system offers fuel economy and emissions benefits of ‘up to 5 per cent.’

Dynamics

The F-Type’s overall torsional rigidity is 10 per cent. greater than for the all-aluminium XKR-S, but of greater significance are increases in local point mobilities. Using Computer Aided Engineering programs, gains of up to 30 per cent have been achieved in lateral stiffness in key areas such as the front suspension mounting points. The stiffer the underlying structure, the greater the precision with which the suspension can be made to work. In essence, if all components remain exactly in their correct positions with respect to each other during cornering, the car will handle as well as its underlying design will allow.

As we have mentioned, the F-Type uses double wishbone suspension all-round. Its wheelbase is 2622mm; front and rear tracks are 1585mm and 1627mm. These figures compare with 2650mm, 1638mm and 1595mm for the mid-engined Audi R8 Spyder. (It is also worth noting that the Audi, which like the Jaguar is built from aluminium, weighs around the same at the kerb.)

Reducing the front and rear overhangs also helps in concentrating the mass within the wheelbase, reducing the polar moment of inertia and giving the car a more immediate turn-in, all other things being equal. To gain the greatest benefit from this, Jaguar apparently paid rather obsessive attention to mass distribution: the Company claims that this is why not just the battery but even the washer fluid reservoir has been placed in the boot rather than under the bonnet. We aren’t totally convinced.

The F-TYPE uses an alloy front subframe which reduces the front axle load, while a stiffer front knuckle, also in aluminium, provides the greatest accuracy in steering response and feedback. This has allowed the fitment of the quickest steering rack ever on a Jaguar.

The balance between ride and handling has been set in favour of involving, exploitable handling, though Jaguar naturally claims that the ride never deteriorates into harshness. The Dynamic driving mode fitted to the F-Type enables the driver to emphasise the sporting character of the car further by sharpening throttle response, increasing steering weighting, performing gear changes more quickly and higher up the rev range and by allowing a greater level of slip before the stability control intervenes. Selecting Dynamic mode also prevents automatic upshifts when the gearbox is used manually.

Additionally, the F-Type S and V8 S models are fitted with Jaguar’s Adaptive Dynamics system that actively controls vertical body movement, roll and pitch rates. The system continuously monitors driver inputs and the attitude of the F-Type on the road, adjusting damper rates accordingly up to 500 times a second. The presence of the Adaptive Dynamics system also allows the F-Type S and V8 S to offer a Dynamic Mode with greater functionality, and in these models it also offers enhanced body control through firmer damping rates.

A Configurable Dynamics option is another first for a Jaguar. This allows the driver to select which elements of the Dynamic Mode are required; so, for instance, the steering weight and throttle response can be sharpened while allowing the ride to remain unchanged. Configurable Dynamics also adds functionality to the central touchscreen aimed at track use of the car. The system allows drivers to record lap and split times and will provide information on throttle and brake inputs and even G-forces generated.

Driver environment

‘We wanted the experience of sitting in the F-Type to be exciting. A sports car cockpit should be an intimate place and so we aimed to get a sense of the surfaces falling towards and then wrapping around the driver.

‘What we’ve done is given it the essence and spirit of doing what you want to do rather than what’s expected of you. The more processed this world becomes, the more important that is.’

These are the words of Ian Callum, Jaguar’s Director of Design. In practice, the cabin was designed as a ‘one plus one’ sports car, focused on the driver and their interaction with the car. The passenger is just coming along for the ride.

Jaguar’s stated aim was to create an enveloping cockpit for the driver with all the controls placed naturally to hand and logically grouped so that there would be no distractions from the driving experience. A clear division exists between the driver and passenger sides of the cabin, created in the first instance by a grab handle which sweeps down from the top of the centre console and wraps around behind the gearbox selector and Dynamic Mode buttons, sending the clear message that these are driver interfaces. The handle also, of course, serves as a signal to the passenger that some spirited driving could be in store.

Further differentiation is provided by the use of different finishes in the driver areas with a more ‘technical’ grain (?) to the top of the instrument panel and centre console in comparison to that found on the passenger side of the car. In the S and V8 S models, the main control interfaces — the Engine Start button, steering wheel mounted gearshift paddles and Dynamic Mode toggle — are highlighted in an orange finish, similar to that used on the markings on professional divers’ watches.

The small diameter three-spoke steering wheel is also available in either flat-bottomed form or with alcantara trim. The wheel frames a brace of analogue instruments, with the numerals on the rev counter being larger and bolder than those on the speedometer. A TFT screen between the two dials provides further information for the driver as necessary.

Jaguar pioneered the use of a (Bosch) touchscreen interface for controlling the majority of its cars’ functions, but with the F-Type it was deemed important that there were more physical interfaces and touchpoints for the driver. Particularly, the heating and ventilation functions have been separated out from the touchscreen and now have physical controls beneath it. Commendably, rotary dials control the climate for each side of the car and feature a screen at their centre to indicate temperature and status. This also allows the controls to fulfil a dual-purpose: in cars fitted with heated seats, pushing the left or right hand rotary control alters their functionality, allowing them to control seat temperature. A row of toggle switches below the dials echoes Jaguar sports cars of the past and control further climate functions.

The ventilation system features Jaguar’s characteristic ‘deployable’ vents on top of the centre console. Controlled by the climate control system, these are hidden until required to provide rapid high-level temperature regulation, at which point they rise up from the top of the centre console.

Sports seats featuring electric adjustment of the recline and height functions with manual control of fore and aft movement (to save weight) are the standard specification. Optional Performance seats can be supplied with additional side bolstering and prominent wings for greater support during high speed cornering. Both variants can also be specified with full electric adjustment which includes adjustable lumbar and side support.

The F-Type is available with three audio systems, two of which come from British experts Meridian. These offer either 10 or 12 loudspeakers with outputs of 380W and 770W respectively. The Meridian systems benefit from the company’s experience in digital signal processing. The top of the range offering also features Meridian’s proprietary Trifield System which places both occupants at the centre of their own perfectly focused surround-sound field.

Jaguar F-Type F-Type S F-Type V8 S
Cylinders 6V 6V 8V
Block/head Al/Al Al/Al Al/Al
Valves 4 4 4
VVT IE IE IE
Aspiration/
geometry
S S S
Injection
pressure
20MPa 20MPa 20MPa
Bore/stroke 84.5/89.0 84.5/89.0 92.5/93.0
Swept volume 2995cc 2995cc 5000cc
Compression
ratio
10.5:1 10.5:1 9.5:1
PS/rpm 340/6500 380/6500 495/6500
Nm/rpm 450/3500 460/3500 625/2500
Maximum speed 161 171 186
0-100km/h 5.3 4.9 4.2
Combined MPG
(l/100km)
31.4
(9.0)
31.0
(9.1)
25.5
(11.1)
CO2 g/km 209 213 259
Emissions EU5 EU5 EU5
Transmission
— I
— II
— III
— IV
— V
— VI
— VII
— VIII
— Final drive
— I/VIII
A8
4.714
3.143
2.106
1.667
1.285
1.000
0.839
0.667
3.15
7.07
A8
4.714
3.143
2.106
1.667
1.285
1.000
0.839
0.667
3.31
7.07
A8
4.714
3.143
2.106
1.667
1.285
1.000
0.839
0.667
2.56
7.07
Driven wheels Rear Rear Rear
Fuel tank (l) 72 72 72
Kerb mass 1597 1614 1665
PS/t 213 235 297
Nm/t 282 285 375
Length 4470 4470 4470
Width 1923 1923 1923
Height 1296 1296 1307
Wheelbase 2622 2622 2622
Track
— front
— rear

1585
1627

1585
1627

1585
1627
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