||2-door convertible, production car
|Miles Per Gallon:
||355 bhp @ 6600 rpm
||295 lb-ft @ 4600 rpm
||f: 58.5 / r: 59.7 in
||--.- sec @ --- mph
|Braking, 60-0 mph:
|Nürburgring Lap Time:
Just months after launching the highly acclaimed 997 911 Carrera and 911 Carrera S Coupes, Porsche introduced the Cabriolet versions of both cars as 2005 models.
S designates special Porsche models
An S designation has a very special meaning at Porsche, signifying a unique model, not a mere trim upgrade or option package.
The larger and more powerful new 3.8-liter engine is only one of several features that distinguish the 2005 Porsche 911 Carrera S Cabriolet, which also comes with the new Porsche Active Suspension Management technology, larger brakes with red-painted calipers, larger wheels, standard Bi-Xenon headlights, a sports steering wheel, aluminum-look interior trim and a silver-colored rear deck lid logo.
With this new powerplant, the 2005 Porsche 911 Carrera S Cabriolet can accelerate from a standing start to 60 miles per hour (96 km/h) in just 4.7 seconds. It can reach 99 mph (160 km/h) in a mere 11.0 seconds.
Lower center of gravity
Contributing to the dynamic capabilities of the 2005 Porsche 911 Carrera S Cabriolet is a carefully designed convertible top. While fully suited for even the coldest winter weather, the new top weighs only 93 pounds (42 kilograms) including all of its system components. This represents only half of the weight of a collapsible metal roof like those used on some premium-class convertibles. This lighter weight top and system components also help to lower the center of gravity of the new Porsche convertibles, thus enhancing the cars dynamic potential. Also contributing to this new lower center of gravity is the re-engineered 2005 Porsche 911 chassis that features a lower seating position.
Porsche Stability Management provides active safety
To further enhance dynamic control, the 2005 Porsche 911 Carrera S Cabriolets is equipped with the new, second-generation Porsche Stability Management (PSM®) as standard equipment. PSM is a technology designed to help the driver maintain control of the car. Porsche Stability Management uses data from several sensors to detect a loss of grip and enhances driver control by applying braking to individual wheels and, if necessary, by reducing engine torque.
For 2005, PSM benefits from new anti-lock brake sensors that take their readings not from conventional wheel pulses but from multi-pole seats fitted directly on the wheel bearings. These improved signals allow more precise processing and control. Instead of conventional shaft valves, linear solenoid valves adjust brake pressure with nearly infinite precision.
With a wider track and slimmer, more accentuated waistline, the Porsche 911 Carrera S Cabriolet has a more powerful and athletic stance, and those characteristics are more than cosmetic changes; the car has an expanded envelope of dynamiccapabilities. While the wheelbase remains 92.5 inches (2,350 mm) and overall length and height are increased by less than two-tenths of an inch compared to the previous 911, the 2005 model rides on front and rear tracks that are nearly an inch wider than previously. Overall width is nearly 71.2 inches (1,808 mm),almost an inch and half wider than the previous generation.
Wider, lighter suspension
The front and rear, the suspension has been re-engineered to enhance ride and handling characteristics. With performance and safety in mind, Porsche engineers redeveloped the front axle sub frame,widening the structure and the axle pivot points by 1.18 inches (30 mm). To reduce weight and to improve airflow to the brakes, new hollow front axle pivot bearings replace solid components andreinforced and larger diameter wheel mounts are used. To enhance ride comfort, hydraulic suspension mounts are used, suppressing high-frequency vibration and minimizing the transmission of unwanted vibrations to the steering system.
In the rear, the axle is 1.34 inches (34 mm) wider and the multi-arm axle and its aluminum sub frame are made of more rigid components. However, the sub frame also is lighter, by approximately 2.2 pounds (one kg). Porsche engineers moved the pivot points of the upper track control arms up by 0.39 inches (10 mm) and the pivot points of the lower arms down by 0.20 inches (five mm), increasing the anti-squat effect by 25 percent, providing better support of lateral forces and assuring directionalprecision in turns.
A new hollow-cast aluminum wheel mount that is 10 percent lighter but also stiffer than the former solid component.
Anti-roll bar pivot points have been changed to provide more direct response, reduce body roll in turns and reduce friction, which enhances the sensitivity of new aluminum springs that are some 70 percent lighter than conventional steel springs.
Instead of steel and rubber, rear suspension mounts use internal elastic foam that reduces weight by 45 percent and improves noise and vibration control.
Porsche Ceramic Composite Brakes
Porsche Ceramic Composite Brakes are available on the Carrera S Cabriolet. Instead of metal, the 13.78-inch (350 mm) brake discs are a ceramic material that provides high and consistent levels of friction during application. They also weight approximately 50 percent less than metal discs and thus reduceunsprung masses, by 34.4 pounds (15.6 kg).
For 2005, the Porsche Ceramic Composite Brakes are more rigid, yet include more interior cooling ducts. Fiber reinforcement on the friction surface is increased, significantly enhancing resistance toabrasion under high loads.
The Cabriolets design evolution features a new, oval-shaped headlamp set into an arching front fender with separate turn indicator and fog lamps set horizontally into the curving edges of the front bumper above redesigned air inlets.
Smoothing the surfaces and enhancing the design of transitional areas beneath the front of the cars to create a low-pressure area that increases downforces on the front axle also help grip. The section radii of the front end and wheel wells also controls airflow to reduce lift. Special air ducts on the vehicles new, longer and smoother under-floor cover helps to direct cooling flow to the brake discs, transmission and differential. The cover itself significantly reduces air resistance and lift.
Wheel spoilers are used to reduce drag by guiding air around the wheels. Optimized brake air spoilers and pivot bearings ensure effective air around the discs, reducing brake disc temperatures bysome 10 percent.
The new design also includes new double-arm rearview mirrors. The mirrors, similar in design to those on the Porsche Carrera GT supercar, guide air along the side of the car toward the rear spoiler, thus reducing turbulence that might otherwise result in wind noise inside the vehicles cabin. At the same time, the design of the mirrors helps to keep dirt and moisture off the side windows. The mirror casing and double-arm design increases downforce on the front axle and, by channeling air toward the rear spoiler, increases positive forces on the rear axle as well.
The flow of air used to provide engine cooling improves by some 20 percent. Air leaving the front radiator flows sideways into the wheel arch rather than downward in front of the wheels. This reduces losses in the airflow ducts and minimizes lift effects on the front axle.
Special ram-air flaps around the engine fan also boost cooling airflow without having to enlarge the air scoop openings. At low speeds, the flaps remain closed and air is drawn only through the heat exchanger, but at around 45 mph (70 km./h), the flaps open under ram pressure and provide enhanced cooling.
3.8-liter engine for Carrera S
To create the more powerful 3.8-liter engine that provides 355 horsepower for the 2005 Porsche 911 Carrera S Cabriolet, engineers did more than simply increase the bore diameter by 0.12 inches (three mm). They also changed the intake manifold and modified the intake camshaft lift pattern. Injector angles have been changed, assuring that more fuel goes to the center of the combustion chamber in the intake stroke. This means an even better fuel/air mixture, reduces exhaust emissions (even after a cold start) and produces more torque than the 3.6-liter throughout the power curve.
The entire intake system was redesigned and provides smoother flow with less resistance.
A Helmholtz resonator is used to refine acoustics. This provides more than 18 cubic inches (0.3 liters) of additional resonance volume between the hot-film air mass meter and the throttle butterfly and is activated between 5,000 and 6,000 rpm to reduce oscillations in intake sounds. Porsche has applied for a patent for this technology that provides a deep, throaty sound without aggressive peaks.
Higher combustion forces produce more power but also more torsional crankshaft vibration, so Porsche engineers have integrated a vibration damper in the pulley at the end of the crankshaft. Conventional vibration dampers are made of cast iron but Porsche engineers devised an aluminum damper that reduces weight by some 3.3 pounds (1.5 kg) while controlling vibrations to a level even lower than the 3.6-liter engine.
Amazingly, the 3.8-liter engine weighs no more than the 3.6-liter unit thanks to its lighter intake manifold and weight optimization within the cylinder head.
While the 3.8-liter engine uses twin radiators like the 3.6-liter powerplant, it has a higher performingcooling pump and an oil/water heat exchanger with two additional cooling layers.
New six-speed manual transmission
To deal with the new engines 295 pound-feet of torque, Porsche developed a new six-speed manual gearbox that is used on both the 2005 Porsche 911 Carrera Cabriolet and the 2005 Porsche 911 Carrera S Cabriolet.
The transmission has thicker shafts and wider gears but weighs no more than the previous manual. Extra-thin aluminum used for oil chamber walls save weight and also reduce splash effect and flow losses and thus increase the efficiency of the gearbox.
Even though gear ratios have been reduced by around five percent, the use of larger rear wheels results in achieving top speed in sixth gear just before maximum engine speed is achieved.
While brass synchronizing rings were formerly used, the new transmission has steel rings in all gears and thus can handle higher power loads. For the first time, Porsche uses wear-resistant carboncoated first, second and third-gear synchronizing rings, and boosts from double to triple synchronizing for first and second gears and from single to double for third gear, retaining single synchronizing for gears four, five and six.
The driver will notice this change in the reduced forces and shorter travel needed to change gears. Shifter travel is reduced by some 15 percent. Shifting also is smoother and more precise because of relocation of the shift lever pivot point and lower-friction shift cables.
Porsches single-disc dry clutch with lead-free pads is retained for the 2005 Porsche 911 Carrera Cabriolet while the 2005 Porsche 911 Carrera S Cabriolet gets a new self-adjusting clutch.
Enhanced Tiptronic S available
Tiptronic S is Porsches optional automatic transmission system that allows manual gear selection via switches on the steering wheel. The five-speed unit allows the driver to use the thumb switches to change gear momentarily, for example, for passing or to downshift for a curve, even while the floor lever remains in its automatic position.
Several modifications have been made to Tiptronic S in conjunction with the increased torque produced by the 3.8-liter engine in the 2005 Porsche 911 Carrera S Cabriolet.
Now, instead of making the first-second shift at 6,900 rpm under full power acceleration, Tiptronic S holds first gear until the engine achieves 7,200 rpm.
In addition, the oil pressure build-up has been fine-tuned and clutch plates modified to allow the Tiptronic S to shift more smoothly.
The interiors of the 2005 Porsche 911 Carrera Cabriolet and 2005 Porsche 911 Carrera S Cabriolet have been completely redesigned with new steering wheels, seats, gauge cluster, improved climate control, standard Porsche Communication Management (with available DVD navigation system), updated audio, upgraded anti-theft system, six standard airbags and the new Sport Chrono Package Plus option.