In a few months Dr. Ing. h.c. F. Porsche AG, Stuttgart, will be presenting the Cayenne, the company's third model series. Featuring an all new 250 kW / 340 bhp V8 engine, the Cayenne S accelerates from 0-100 km/h in just 7.2 seconds and reaches a top speed of 242 km/h (150 mph). The Cayenne Turbo will surpass even these impressive figures by developing a maximum output of 331 kW / 450 bhp from its 4.5 litre engine, thanks to two exhaust turbochargers and intercoolers. This ensures acceleration from 0-100 km/h in only 5.6 seconds and provides a top speed of 266km/h (165 mph).
A manufacturer of sports cars with the emphasis on "sports", Porsche has made sure that this outstanding performance goes hand in hand with an equally supreme standard of sporting, agile handling and excellent driving dynamics. Indeed these are the decisive criteria in the creation of sports cars at the Porsche Research and Development Centre in Weissach. With the introduction of the new Cayenne, Porsche is carrying over this philosophy into a new vehicle segment without in any way overlooking the requirements for outstanding off-road capability. Various technology highlights make their world debut in the Cayenne therefore ensuring an optimum blend of supreme on-road and equally assured off-road driving qualities.
Porsche Traction Management - A New Generation Of Four-Wheel Drive
One of these highlights is Porsche Traction Management (PTM) permanent four-wheel drive featured as standard, feeding 62 per cent of the engine power to the rear and 38 per cent to the front wheels in the basic mode. A multi-plate clutch operated by an electric motor and controlled electronically is then able to vary the distribution of power according to specific driving conditions, whenever necessary feeding up to 100 per cent of the engine torque to either the front or to the rear.
Porsche Traction Management may be rightly regarded as an all-new generation of four-wheel drive with a decisive impact on the Cayenne's driving dynamics in every respect. The electronically controlled longitudinal differential lock and the rear axle differential (available as an option) not only responds to any lack of traction on the front or rear wheels, but also incorporates sensors measuring the speed of the vehicle, its lateral acceleration, the steering angle and position of the accelerator pedal. PTM thus calculates the optimum locking action on both axles and distributes the torque as required to the front and rear wheels.
Some Of The Particular Benefits Provided By PTM Are As Follows:
- Excellent driving stability and traction in all situations, regardless of surface friction
- Improved steering and control by opening the longitudinal differential lock in order to avoid any understeer
- Enhanced vehicle control when driving on the limit, again thanks to the longitudinal differential lock
- Improved directional stability and tracking control by appropriate activation of the longitudinal differential lock
- Improved traction by increasing the degree of locking action before the wheels start to spin
Porsche Stability Management (PSM), also featured as standard, maintains a constant dialogue with PTM but only intervenes when the vehicle reaches its physical limit. Masterminding essential systems such as ABS, ASR (anti-slip regulation) and the ABD (automatic brake differential), PSM is immediately available whenever the Cayenne enters critical over or understeer conditions telling the PTM to open the differential locks in order to re-stabilise the car by applying the brakes specifically on individual wheels.
Sporting And Agile On The Road, Robust When Driving Off The Beaten Track
The suspension provides the basis for supreme driving dynamics combining optimum safety, motoring comfort and off-road capabilities. Newly developed for the Porsche Cayenne, the front axle is an extra-large double track control arm configuration mounted on its own subframe. The large distance between the individual track control arms keeps forces acting on the suspension to a minimum, thus ensuring precise wheel guidance for tremendous agility and an extremely low level of any adverse forces. Incorporating extra-large rubber mounts, the elastic subframe bearing serves furthermore to keep out road noise with maximum efficiency.
Made of high-strength steel, the subframe, through its structural design, enhances the high standard of safety to an even higher level and helps to ensure extra comfort and safety. Through the design of the subframe, the arch-shaped crossbar and the inclined ramps at the front, the Cayenne benefits from ample ground clearance of up to 273 millimetres or 10.75" providing outstanding off-road driving qualities. The steering transmission with its variable transmission ratio and the differential are both well protected on top of the subframe, again helping to guarantee robust driving ability off the beaten track.
The rear axle is another new development by Porsche. To offer the highest standard of dynamic driving performance, the axle configuration at the rear is an elaborate multi-arm concept easily able to handle both high tractional forces and the high service load the Cayenne is able to carry. In the interest of extra comfort and noise reduction, the rear axle is also mounted on a subframe resting on extra large, hydraulically dampened rubber bearings. And the subframe itself is once again made of high-strength steel in order to optimise weight and maximise the stiffness of the entire structure. To ensure robust strength even on the roughest surfaces, the lower track control arm and the tie-rod are both made of steel plate. The upper track control arm assembly, well protected within the vehicle, in turn is made of extra light forged aluminium components.
Through its particular configuration, the axle kinematics reduces undesired squat and dive when accelerating and applying the brakes, keeping the Cayenne almost entirely flat on the road at all times. The rear axle configuration and the rear toe-in control stabilise the vehicle's driving behaviour particularly in bends and under load change. A special feature of the axle concept is the extra long spring travel for off-road purposes, the pneumatic spring suspension featured as standard on the Cayenne Turbo coming with inward and outward spring travel, respectively of 102 and 118 millimetres on the front axle (4.02 and 4.65") and 124/125 millimetres (4.88 and 4.92") at the rear. Inward and outward spring travel on the steel spring suspension of the Cayenne S is 104 and, respectively, 116 millimetres (4.09 and 4.57") at the front and 135/98 millimetres (5.31 and 3.86") at the rear. As an option, the Cayenne S is also available with pneumatic, air-controlled spring suspension.