|5-door SUV, production car
|Miles Per Gallon:
|450 bhp @ 6000 rpm
|457 lb-ft @ 2250 rpm
|f: --.- / r: --.- in
|13.5 sec @ 104 mph
|Braking, 60-0 mph:
|Nürburgring Lap Time:
With unsurpassed versatility on all road surfaces, the 2004 Porsche Cayenne brings exceptional dynamic capabilities to the sport utility category. While best known for its rear-wheel-drive sports cars and for its success in major international motorsports competition, Porsche’s expertise in four-wheel-drive dates back more than 100 years to the Lohner-Porsche, one of Prof. Ferdinand Porsche’s first race and rally winning vehicles. Porsche engineers continued to work on all-wheel drivetrain technology throughout the years that followed. Even NASA called on Porsche’s all-wheel-drive expertise to help develop the lunar rover.
Nearly a quarter of a century ago, Porsche’s 959 supercar won the grueling 1986 and 1987 Paris-Dakar marathon rallies, leading to the development of the 911 Carrera 4 and the latest generation Porsche 911 Turbo.
Now, the Cayenne takes that four-wheel-drive expertise to new venues as the Cayenne S and Cayenne Turbo prove their capabilities in off-pavement expeditions around the world.
But Cayenne is a sport utility that lives up to its name, which is taken from the very hottest of red peppers. Its zestful spiciness includes 0 to 62 mph (100 km/h) sprint times of as little as 5.6 seconds for the 450-horsepower Cayenne Turbo, which has posted among the fastest laps ever around Germany’s famed Nürburgring by any production vehicle.
The Cayenne may have the architecture of an SUV, but it has the soul that is part of every Porsche product. Porsche Traction Management not only claws its way up a rocky trail, but it provides sure-footed traction for high-speed lane changes. With four doors, luxuriously comfortable seating for five, room for the gear a family needs to enjoy an active lifestyle, and a towing capacity of 7,716 pounds (3,500 kg.), the Cayenne is the first Porsche to provide such true utility.
With twin turbochargers boosting the output of its 4.5-liter V8, the Cayenne Turbo delivers 450 horsepower and 457 lb.-ft. of torque, power that propels it from a standing start to 60 mph in a mere 5.5 seconds and to a top track speed of 165 mph. But the Cayenne Turbo is just as capable off-pavement, thanks to its combination of Porsche Traction Management with standard air suspension that can provide nearly 11 inches of ground clearance for traversing rough terrain.
Like the Cayenne S, the Cayenne Turbo comes with such standard equipment as Porsche Stability Management; a six-speed Tiptronic S transmission; front, side and curtain airbags; full leather upholstery; and automatic climate controls. The Cayenne Turbo adds such features as an aluminum-trimmed interior and the new Porsche Communications Management technology that includes a navigation system and Bose Cabin Surround Sound System.
Biturbo 4.5-liter V8
The Porsche V8 is an all-new, Porsche-designed 4.5-liter unit with 32 valves (two intake and two exhaust valves per cylinder), Porsche’s VarioCam® technology, and integral dry sump lubrication. Two turbochargers recycle the engine’s exhaust gases and boost its power to a staggering 450 horsepower (SAE) at 6,000 rpm and to a whopping 457 lb.-ft. of torque throughout the 2,250 to 4,750 rpm range. The two banks of cylinders are placed at a 90-degree angle. The engines are built at Porsche’s factory in Stuttgart-Zuffenhausen, Germany.
Because of such higher loads, the Cayenne Turbo has cylinder heads made of special high temperature-resistant aluminum alloy similar to that used in Porsche racecars. The intake ducts are modified for the greater fuel/air mixture, and the cylinder head features double valve springs on the exhaust side to ensure maximum engine performance. The Turbo also has special forged pistons and additional oil cooling jets.
The Porsche V8 engine is designed to operate smoothly at an angle of 45 degrees off-horizontal, thus providing optimum off-pavement abilities. This required modification of the oil circuit and crankcase-venting system, most notably separate oil re-flow ducts leading from the cylinder heads into the oil sump. Separation of the oil circuit from the vent ducts enables engine oil to flow quickly and directly back to the oil sump to maintain a sufficient oil supply at all times.
On extreme gradients, an efficient supply of oil is also guaranteed by added oil extraction from the rear section of the oil sump, by the oil intake opening for the main oil pump being lowered right to the bottom point, and by a baffle wall in the oil sump. The V8 shares much of its internal architecture with the liquid-cooled six-cylinder engine that was developed to power the Porsche Boxster®. However, Porsche engineers developed specific components and dimensions for the Cayenne’s new V8. For example, while the 3.66-inch (93 mm) cylinder bore is the same as the Boxster’s, the V8 has a longer stroke of 3.27 inches (83 mm). The V8 has a two-piece cylinder head similar to that developed for the powerful 911 Turbo, and the Cayenne engine’s cylinder head makes use of an aluminum/silicon alloy that can withstand very high temperatures.
As with all other Porsche models, the new V8 makes use of Porsche’s VarioCam® technology. For the Cayenne’s V8, VarioCam can adjust the intake camshafts by as much as 25 degrees, ensuring outstanding torque characteristics as well as optimum fuel efficiency and lower emissions.
Engine coolant is distributed to the crankcase and cylinder heads by a distribution pipe located above the transmission. The water pump, mounted at the front of the engine, pumps coolant through a pipe located in the interior of the engine’s V. Approximately 20 percent of the coolant flows through the crankcase in a lengthwise direction with 80 percent flowing through the cylinder heads in a “cross flow” architecture from the hot to the cold side. Heat from the engine oil is fed into the coolant through an oil/water heat exchanger.
Powerful and Efficient
The stainless steel exhaust system features an exhaust pipe for each row of cylinders that is connected downstream of the main catalysts by a crossover pipe. This architecture allows enhanced torque at low engine speeds. The pre- and main catalysts are metallic, allowing thinner design of the coated inner walls. This system also provides a larger overall area within the catalyst ducts, ensuring higher efficiency, longer service life and more rapid build-up to the temperatures required for maximum catalyst efficiency.
Two oxygen sensors control the catalysts. This dual-sensor control minimizes exhaust emissions, enabling both the Cayenne S and the Cayenne Turbo to meet LEV (low emission vehicle) standards in the United States and to fulfill the EU4 standards that go into effect in Europe in 2005. The Tiptronic S transmission is specially tuned for the increased power of the Turbo engine.
Special Turbocharged Tuning
As on the Porsche 911 Turbo, the Cayenne Turbo’s boosters are in parallel arrangement. Small intake and short exhaust manifolds and a mixed-flow turbine with reduced mass inertia ensures response and performance, eliminating so-called turbo lag.
The turbo housing is made of high quality cast steel, assuring temperature control and optimizing combustion under full load. The compressed air flowing out of the turbine is cooled to provide a high cylinder charge and to reduce component temperatures. Intake air flows to the two compressors through separate air filters for the left and right cylinder banks. Finally, the compressed air flows through separate intercoolers positioned in front of the left and right wheel arches. Bypass valves are integrated into the turbine housings and turbocharger pressure is adjusted through a joint cycle valve controlled by the engine management system. Maximum turbocharger pressure is approximately 8.7 pounds per square inch (.6 bar) and is reached at an engine speed of 2250 rpm. Boost pressure then reduces slightly, to 7.3 psi (.5 bar), where it remains until the engine reaches its maximum horsepower at 6000 rpm.
For the Cayenne, Porsche engineers developed the Porsche Traction Management (PTM) permanent four-wheel drive system, an air suspension system with a self-leveling feature and six adjustable ride height positions, and Porsche Active Suspension Management (PASM), an electronically variable damping system that stabilizes body sway during sudden gas or brake pedal applications or when driving on rough terrain. These systems work together to ensure that the Cayenne offers both supreme on-pavement and outstanding off-pavement driving qualities.
PASM and PTM also work in conjunction with PSM (Porsche Stability Management), which intervenes when the vehicle is driven to the limit of adhesion and stabilizes the Cayenne in oversteer or understeer conditions to keep it headed in the direction the driver intends.
Suspension - Dynamic Handling
The Cayenne’s suspension provides the secure foundation for exceptional driving dynamics. It combines optimum safety, motoring comfort and off-pavement driving capabilities.
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, ensuring precise wheel guidance for agility and minimizing the influence of any adverse forces. Incorporating extra-large rubber mounts, the elastic subframe bearings keep road noise transfer to a minimum.
Made of high-strength steel, the subframe design has an arch-shaped crossbar and inclined ramps at the front that give the Cayenne ample ground clearance, up to 10.75 inches (273 mm) with the air suspension system.
The rear axle is a Porsche development. The rear axle configuration is an elaborate multi-arm concept easily able to handle both high traction forces and the Cayenne’s high service load capabilities. In the interest of extra comfort and noise reduction, the rear axle also is mounted on a subframe resting on extra-large, hydraulically dampened rubber bearings. This subframe also is made of high-strength steel for optimal weight and maximum structure stiffness. The lower track control arm and the tie-rod are made of steel plate to ensure robust strength even on the roughest surfaces. The upper track control arm assembly, which is well protected within the vehicle, is made of extra-light forged aluminum components.
Through its particular configuration, the axle kinematics reduce undesired squat and dive when accelerating and braking, keeping the Cayenne almost entirely level on the road at all times. The rear axle configuration and the rear toe-in control stabilize the vehicle’s driving behavior particularly in curves and under load change.
Porsche offers air suspension in combination with Porsche Active Suspension Management (PASM), a new shock absorber variable damping system. Operated electronically, PASM adjusts damper forces infinitely as a function of surface conditions and the driver’s driving style.
A typical example of PASM intervention occurs during powerful application of the gas and/or brake pedal or when driving on particularly rough terrain. PASM serves to steady any body sway and dive motions by monitoring body movement through five accelerometers. As soon as the motion of the Cayenne’s body exceeds a certain limit depending on specific driving conditions, PASM intervenes and stabilizes the vehicle by acting on the individual dampers.
PASM also gives the Cayenne driver the opportunity to choose among three damper settings while driving – Comfort, Normal or Sport.
Consistently operating in the background, PASM always maintains its active control function, comparing the operator’s driving style with the program currently in use. Whenever the driver has chosen a particularly comfortable damper setting but is driving in a more sporting or dynamic style, the system automatically switches over to the sport mode and makes the dampers firmer.
Large Disc Brakes
To ensure maximum braking efficiency, Porsche engineers equip the Cayenne with 13.78-inch (350 mm) inner-vented front discs with six-piston aluminum monoblock calipers and 13-inch (330 mm) inner-vented rear discs with four-piston aluminum monoblock calipers with pad-wear sensors. The front and rear rotors are 1.34 inches (34 mm) and 1.10 inches (28 mm) thick, respectively. Anti-lock braking technology is standard.
Because of the risk of contamination under off-pavement conditions, the Cayenne’s brake discs are not cross-drilled. Porsche engineers found in their extensive testing that cross-drilled brakes can collect debris that can cause premature wear and even damage to the braking system.
The Cayenne brakes have passed Porsche’s extreme fade test. This test involves 25 full-force braking applications from 90 percent of the vehicle’s top speed down to 62 mph (100 km/h). This must be accomplished while maintaining a consistent deceleration of 0.8g.