Equipped with a V10 engine that produces more than 600 horsepowerand with the most advanced, cutting-edge automotive technologies, the 2004Porsche Carrera GT uses the undiluted qualities of a genuine racecar to provide an unprecedented driving experience on the road. Among the car’s unique features are its 5.7-liter,605-horsepower (SAE) V10 engine; its monocoque chassis with engine andtransmission mounts made of carbon-reinforced plastic (Porsche has registeredfor a patent on this design principle which uses aerospace materials); and the firstuse of a ceramic composite clutch in a production car. Its aerodynamic and race-bredsuspension package provides safe and stable travel at speeds of up to 205 mph(330 km/h), and the Carrera GT features a lot of lightweight materials, such asmagnesium for the car’s huge wheels and special sport seats.The result of such artistic and athletic equipment is a car that accelerates from astanding start to 62 mph (100 km/h) in only 3.9 seconds, reaches 100 mph(160 km/h) in less than seven seconds, 125 mph (200 km/h) in less than 10seconds, and can achieve a top test-track speed of 205 mph (330 km/h).The Porsche Carrera GT made its stunning yet fitting debut as a prototype carat the famed Louvre art museum in Paris in the fall of 2000. After undergoingdevelopment and testing, the final production version was unveiled at the 2003Geneva show. The Porsche Carrera GT will be built at Porsche’s new plant in Leipzig, Germany, with deliveries beginning late in the 2003 calendar year.
The Porsche Carrera GT design clearly indicates its athletic abilities. Yet contraryto prototypes used only in motorsports, the Carrera GT’s design and charactershows clear links to Porsche’s production cars.From the front, the Carrera GT bears the typical Porsche face, with an extreme,swept-back “arrow” design of the front lid with wings rising up at the sides muchlike the 718 RSK Spyder of the 1960s. As on the awesome Porsche 917 racecars,flat glass covers a pair of large projection headlights that feature the most advancedand sophisticated headlight technology available with V-shaped Xenon headlampunits. Just as on the Porsche 911 Turbo, three extra-wide air intakes in the lowerfront fascia underscore the Carrera GT’s clear commitment to outstandingperformance by providing air to cool a trio of front-mounted radiators, as well asthe ceramic front brakes.
The Carrera GT’s look is even more dramatic in side view, where its taut, stretchedand sleek shoulder line comes clearly into view. The mid-engine architecture isaccented by a cockpit oriented clearly toward the front of the car with a longpanel between the door and rear axle. New exterior mirrors have V-shapedbases and match the rake of the car’s A pillar.Large air intakes and side outlets in front of and behind the doors add to the car’sdramatic and dynamic appearance. But, as is typical with Porsche, with form comesfunction; these openings are designed to ensure airflow to and from the engine,transmission, brakes and air conditioning systems. Literally “cut into” the basicdesign of the car, just as on an aircraft, the air intakes are part of a highlyfunctional aerodynamic airflow surface that enhances both the Carrera GT’s athleticabilities and its aesthetic appeal.
To provide a view of the engine and to enhance cooling, cross-drilled stainlesssteel power domes stretch back from the rear panel behind the Carrera GT’s seats.Two supplemental safety bars just behind and above the seats enhance safetyand security as well as reinforcing the car’s dramatic design. However, thesebars also have another functional role: they anchor the removable roof when it isin place over the cockpit.At the rear of the car, a wing that spans between the tops of the fenders providesthe downforce needed for high-speed stability. To assure stability at higher speeds,the wing rises 6.3 inches (160 mm) when the car achieves 75 mph (120 km/h),thus increasing downforce by some 30 percent. The wing retracts to its normalposition when the car slows to less than 50 mph (80 km/h).
A racing-style diffuser beneath the rear section of the car enhances the aerodynamiceffect of the wing and also provides a visual counterbalance to the wing’s upwardarc. Two stout tailpipes are integrated into the carbon fiber panel on either sideof the rear license plate mount. The ribbed cover around the tailpipes is designedto enhance cooling and again reflects Porsche’s clear belief in form following function.
Although hidden from view, the underside of the car was designed just as carefullyas the Carrera GT’s beautiful and sleek body. A fully covered underfloor providesground effects to meet the demands of high-speed aerodynamics. The under floorstructure includes airflow ducts, and the rear diffuser is made of composite carbonfiber and is firmly bolted to the chassis, engine mounts and crash structure.Carefully designed with computerized and wind tunnel evaluation, this under floorsystem channels air to maintain the car’s 30/70 front/rear downforce balance.
Body and Chassis
Porsche’s motor racing division designed and developed the Carrera GT’s bodystructure. The monocoque combines all structural functions. Unlike a conventionalbody shell made from numerous separate components, the monocoque is madefrom only a few elements that are bonded together in a high-pressure furnace toform a single or mono-structure that is exceptionally rigid and strong.Carbon fiber reinforced plastic (CFP) is the generic term for composite fiber materialsthat were developed primarily for aerospace applications but have been widely appliedto motorsports vehicle construction. These materials provide supreme performancethrough their combination of minimum weight and maximum strength and stiffness.On the Carrera GT, CFP is used for the chassis, which includes the windshieldframe (which is reinforced by a steel core) and supplemental safety bar system,engine/transmission support frame, doors, hoods, fenders, underfloor tray andeven in many interior components.
CFP is constructed from bonded layers of materials, including carbon fiber tissue,resin and aluminum or plastic honeycomb material that can be nearly an inch inthickness. Aluminum inserts are laminated at specific points so other componentscan be attached to the load-bearing monocoque structure. The structure is sealedin an airtight foil cover and placed in a high-pressure autoclave furnace, wherethe resins form a polymer and bond the honeycomb to the carbon fiber. Suchcarbon bonding creates a strong, stiff and precise structure that is also resistantto temperature extremes.
The Carrera GT is the first road car built around such a chassis and also the firstwith an engine and transmission support made entirely of CFP, a conceptdeveloped by Porsche’s motorsports department and registered for patent. Thesystem was devised because of carbon-reinforced plastic’s structural strength andthermal resistance.CFP is also used in the Carrera GT’s removable roof, which consists of two lightweightpanels. It is held in place by rapid-action catches and can be stored in the car’sfront luggage compartment.
The Carrera GT has steel reinforcement in its windshield structure and thelongitudinal arms commonly referred to as chassis legs are made from high-strengthstainless steel and help create a crash structure at the front and rear of the vehicle.Aluminum inserts connect the longitudinal arms to the chassis at the front and tothe engine/transmission support frame at the rear. The bumper system is madeof a strong aluminum crossbar and impact tubes.
Porsche’s development engineers have placed the car’s fuel tank in an aluminumdrawer within the monocoque and between the passenger cell and engine compartment.In addition to protecting the fuel tank, the chassis is designed to protect its humanoccupants. The Carrera GT is equipped with three-point safety belts withpretensioners and load limitors, but the seats also are prepared to accept six-pointracing belts. Passive safety equipment includes front and side airbags for boththe driver and passenger. Strong steel tubes built into the Carrera GT’s doorsprovide additional side-impact protection.
Engine
A purebred racing engine powers the Carrera GT. Porsche’s development centerat Weissach, Germany, built a 5.5-liter, normally aspirated V10 engine for racing,and that engine’s bores have been enlarged to displace 5.7 liters in the Carrera GT.Maximum output is rated at 605 horsepower (SAE) at 8,000 rpm, with peaktorque of 435 lb.-ft.The engine has a very low center of gravity, a 68-degree V angle and fourvalves-per-cylinder heads. The engine block serves as a load-bearing part of thechassis structure, yet is so strong that there is no distortion to the cylinder bores.Using dry-sump lubrication reduces the number of engine components and sealsand also helps optimize weight and reliability.
To keep the engine as short as possible, Porsche engineers decided againstusing cylinder liners. Instead, the cylinders are coated with Nikasil, a nickel andsilicon combination coating that improves wear resistance and minimizes internalfriction. The engine has a closed-deck configuration, a principle carried over frommotorsports. This closed-desk architecture enables the cylinders to be cooled byinternal water chambers that directly surround the cylinders. Three front-mountedradiators and cross flow cooling ensure optimum heat transfer even under highengine loads.
The engine weighs only 472 pounds (214 kg.). The block, crankshaft and camshaftsare all made of light alloys. The crankshaft is designed to operate at speeds ofup to 8,400 rpm and is both forged and designed for minimum mass inertia andthus offers maximum torsional stiffness. Pistons are connected to the crankshaft bytitanium connecting rods that are very lightweight. The crankcase is a one-pieceunit that integrates the secondary air ducts as well as the separate bearing blocksfor the camshaft. Camshaft drive is a combined sprocket/chain system with rigidcup tappets that guarantees a stiff and sturdy valve drive with low masses andcompact dimensions. Porsche-patented VarioCam camshaft control provides theintake camshafts with infinite adjustment within a range of 40 degrees.The Carrera GT has a two-chamber exhaust system with one pre-catalyst and amain catalyst on each side. The car already meets European EU4 emissionstandards that do not go into effect until 2005. The exhaust system is made ofstainless steel and is precisely tuned to provide a powerful sound that includesthe high-frequency roar of a thoroughbred racing engine.
Transmission
The engine’s power reaches the rear wheels through a specially developed six-speedmanual gearbox that has compact dimensions and a low center of gravity. Thetransversely mounted gearbox ensures optimum weight distribution without impairingthe position of the rear diffuser.
Rather than carrying the weight of a two-mass flywheel, the transmission uses aspecial shaft design: the first main shaft is a hollow tube housing the long andthin solid shaft. This effectively creates a torsional spring that enables the shaftsto dampen drive impacts and to reduce transmission noise.
The Carrera GT is the first Porsche to feature the Porsche Ceramic CompositeClutch (PCCC®), which is extremely compact and contributes to the car’s low centerof gravity. The PCCC’s low mass also has a positive effect on engine dynamics.Ceramic composite clutches used in racing often have short lives, but Porsche hascreated a new clutch design and configuration with a two-plate dry clutch withceramics made of carbon fiber and silicon carbide that are strong, light and havean exceptional service life. The plates are only 6.65 inches (169 mm) in diameter,less than half the size of typical production car clutch plates.
Suspension
The Porsche Carrera GT chassis and suspension is based on the architecture ofthe Porsche GT1, the car that won the 24 Hours of Le Mans race in 1998. Forexample, as on the GT1, the rear track control arms of the Carrera GT are madeof aerodynamically designed steel tubes. However, Porsche engineers did not forgetthe need for driving comfort on the street when they adapted such racing-bredsystems for the new supercar.
Like a racecar, the Carrera GT uses pushrod suspension with double-track controlarms at all four corners to give the Carrera GT its refined response and behavior,feeding forces smoothly and efficiently into the car’s chassis. Where many carsuse MacPherson spring struts, the Carrera GT’s spring and damper elements areoperated by stainless steel pushrods and pivot levers, which separate the guidancefunction from the spring action. Advantages include more sensitive response andbehavior as well as precise suspension tuning for both high and low speeds.Forged aluminum control arms resting on broad mounts feed wheel forces into thechassis. As on a racecar, the control arms are bolted on the chassis without rubberinsulators, providing the most precise and direct wheel guidance at all times. TheCarrera GT’s superior driving dynamics are further enhanced by a power steeringsystem that has its safety steering column also bolted directly to the monocoquebody structure.
Braking System
The Carrera GT is equipped with Porsche Ceramic Composite Brakes (PCCB®),which have been optimized and enlarged. The cross-drilled composite ceramic brakediscs are 14.96 inches (380 mm) in diameter at all four corners of the car. Thosediscs are 1.34 inches (34 mm) thick, yet are 50 percent lighter than comparablecast iron discs. Porsche composite brakes provide immediate, frictionally consistentand optimized response while slowing the Carrera GT. Maximum brake power isbuilt up within fractions of a second, yet abrasion is kept to an absolute minimumand the brakes have a substantial safety reserve even under extreme loads.Six-piston monoblock aluminum brake calipers front and rear are brand new andfeature extremely large and firmly bolted connections to the wheel mounts, givingthe driver good feel through the brake pedal. Short stopping distances are ensuredby the hydraulic brake servo that builds pressure very quickly and efficiently.
The antilock braking system and traction control serve to ensure dynamic drivingbehavior even in transitional road surfaces and in inclement weather. The CarreraGT has four-channel anti-spin control (ASC) geared specifically for its ceramic brakesto provide short stopping distances with precise steering control. ASC is activatedwhen required throughout the car’s entire range of acceleration, preventing excessivewheel spin on the drive wheels and thus avoiding any instability at the rear of the car.ASC can intervene in engine management to reduce power to the degree required.While they are spinning, the drive wheels are slowed by automatic brake differential(ABD) technology. However, the driver can switch off the traction control functionby pressing a button on the center console.
Wheels
The Carrera GT rides on large, five-spoke wheels, which are the first production carapplication of forged magnesium rims made from a special manufacturing processthat enhances strength while reducing weight. The forged magnesium wheels aresome 25 percent lighter than cast aluminum wheels and thus reduce unsprung weightto a new level. The result is supreme traction as well as smooth and sure springand damper action.The wheels are 19 inches in diameter and 9.5 inches wide for the front of the carand 20 inches in diameter and 12.5 inches wide at the rear. The wheels featuremotorsports-style central wheel locks on their hubs.
Special tires were developed for the Carrera GT. They measure 265/35 X 19 infront and 335/30 X 20 in the rear. The tires are Z rated and have outstandinggrip and consistent behavior at high speeds, yet have a relatively low level of wearfor such high-performance tires.Despite its racing-oriented performance, the Porsche Carrera GT does not have aspartan interior. The cockpit is characterized by function-oriented ambience withextensive use of high-tech materials. Carbon, magnesium and leather dominateinterior materials, with composite components either in their natural state or paintedto match the magnesium pieces.
Interior and Amenities
The car’s center console is made of composite materials covered in galvanizedmagnesium. The shift lever is positioned about halfway up the console and is directlynext to the steering wheel. The shift lever has a ball-shaped knob made oflightweight stratified birch/ash wood meant to remind drivers of the balsa woodshift knob in the 1970 Le Mans-winning Porsche 917.The Carrera GT features a new seat design and structure. The seats are finishedin smooth leather and have manual adjustment because power motors would addunnecessary weight. The seats are made of a composite carbon shell. Each seatweighs only 23.6 pounds (10.7 kg.), compared to 28.9 pounds (13.1 kg.) for theseats in the Porsche GT3 or 44.1 pounds (20 kg.) for the seats in a Porsche 911 Carrera.
Air conditioning is optimized for weight and the car comes with a standard airfilter system. Even though the Carrera GT is a serious performance car, it canbe equipped with many comfort features, including a navigation system andBose® audio.The Carrera GT also comes with its own five-piece set of leather luggage matchedto the car’s interior color – Terracotta, Dark Grey Nature, Ascot Brown/BlackNature. Each piece of luggage is designed for a precise place within the car: theclothes bag fits behind the passenger’s seat, the attaché case fits in thepassenger’s foot well, the shoulder bag fits between the passenger’s seat and door,a center console bag fits beneath the console and there are leather bags in specialstorage boxes within the doors and a travel bag in the luggage compartment.The luggage compartment is lined with a checkered fabric and can hold 2.68 cu.-ft.(76 liters) of cargo. Special leather straps hold the two roof panels in positionwhen they are in the compartment.
Source: Porsche Press Release
| 
RSS
