Porsche Engineering Magazine

Issue 02/2004

Ceramic clutch: The PCCC (Porsche Ceramic Composite Clutch) from Porsche – a world first fitted as standard in the Carrera GT super sports car.

Wheelchair chassis: The electric wheelchair from the Alber company sets new standards in its segment. Porsche Engineering played an instrumental role in the development of the chassis.

Focus on the complete car: Porsche's competence in the development of high-performance variants is particularly evident in the 911 GT3 RS, which has been fitted out especially for motor racing. Contents

Porsche Engineering Group GmbH Porsche is the only car manu- Together with its subsidiaries in (PEG), a subsidiary of facturer to place its comprehensive Germany and abroad, the Porsche Dr. Ing. h.c. F. Porsche AG, is engineering know-how at the dis- Engineering Group offers engineer- responsible for the sports car posal of international customers ing services relating to the area of manufacturer's worldwide contract from various branches of industry. cars and transportation worldwide development activities. under the joint brand name of Porsche Engineering.

Editorial Page 4

Drivetrain Testing Body & Safety Engine Chassis

Thoroughbred racing engineering for safe and enjoyable driving Page 9

The ceramic clutch – a world first from A wheelchair all set Porsche for adventure Page 5 Page 14 To this end, Porsche Engineering is If you would like to know more able to draw on the capabilities of about Porsche Engineering, please over 3,000 employees from the send an e-mail requesting our areas of design, prototype con- image brochure to the following struction, testing, process planning, address:

procurement, logistics or produc- [email protected] Insights tion. The new Porsche 911 comes in two variants Page 21

Electrics & Electronics Complete Vehicle Industrial Engineering Styling Production Support

Expertise in complete vehicle development Page 17

Special Design and testing working hand in hand for 30 years Page 22 Editorial

Dear readers,

Lightweight design. In this issue we High performance. Porsche present the Carrera GT's innovative Engineering has long been a part- body structure made of carbon ner to international vehicle manufac- fiber materials. The development of turers in developing high-perform- this structure called on our engi- ance variants of standard produc- neers to to optimize existing tech- tion vehicles. Early examples here nologies and to try out a whole include the Audi RS2 or the range of new approaches. In addi- Mercedes-Benz 500E in the 1990s. tion to the monocoque, the sub- This issue illustrates the special frame has also been developed in challenges involved in developing a carbon fibre-reinforced plastic high-performance derivative on the (CFRP) - an absolute first for a stan- basis of a standard production dard production vehicle and a highly vehicle by reference to the current practical development for everyday 911 GT3 RS. use. One quality which our customers Once again, this issue presents a small selection of value is our willingness and projects from Porsche's development activities. capability to venture into other fields of application. We develop an Porsche Engineering stands for innovative solutions. array of other products, in addition Solutions which we also offer to you, our international to cars. One area is medical engi- customers. After all, why should you need to re-invent neering. Our experience from the automotive field led to astounding the wheel? results in developing the chassis for an electric wheelchair. Low position design. Another tech- nological highlight is the new We hope you enjoy reading this Porsche Ceramic Composite Clutch issue. (PCCC), which has initially been developed especially for the Carrera GT. In addition to optimis- ing the weight of the vehicle, the lowest possible position has also been achieved for the powertrain. This called for a small clutch, however. Here again, the focus is on practicality in everyday use.

4 Porsche Engineering Magazine 02/2004 Porsche Ceramic Composite Clutch Drivetrain

The ceramic clutch – a world first from Porsche

The ceramic clutch enables a particularly low center of gravity for the engine.

The Carrera GT super sports car is the first standard production vehicle in the world to be fitted with the Porsche Ceramic Composite Clutch (PCCC). The double-disk dry clutch developed by Porsche meets the typical racing requirements of a small diameter and low weight combined with a long service life.

Porsche set itself ambitious aims in in diameter as possible, as the ter of gravity will be. Previously, developing the Carrera GT: The position of the center of gravity is a only a carbon-fiber clutch had been overall objective was to evolve a crucial factor in a vehicle which able to provide these typical racing super sports car from existing sets out to be a super sports car. characteristics. This option would racing vehicle concepts which The smaller the clutch and the have fallen short of the given would be suitable for everyday use shorter the distance between the requirements with regard to service and which could be produced in center of the crankshaft bearings life, driver comfort and practicality small batches. One of the central and the underside of the engine in everyday use, however. topics here was the clutch, which housing, the lower the engine can needed to be as light and as small be installed and the lower the cen-

Porsche Engineering Magazine 02/2004 5 Drivetrain Porsche Ceramic Composite Clutch

robust, heat-resistant and durable option here.

In the first test, a conventional clutch was configured with a short- staple fiber ceramic material. The conventional material failed to withstand the stress induced by centrifugal force and friction heat. The special innovative arrangement of a fabric structure consisting of carbon fibers as the load-bearing ele- ment enabled the strength of the carbon fibre-reinforced silicon carbide disks to be increased to such a degree that the clutch system was able to withstand engine speeds of up to 20,000 rpm combined with extreme thermal loads without incurring any damage.

The Carrera GT is the first standard production vehicle worldwide to be fitted with the new ceramic clutch.

As no appropriate clutch system for the Carrera GT was available on the market, Porsche's engineers teamed up with selected partners to develop a completely new clutch using innovative materials for friction disks and linings.

In the course of these development efforts, the specialists were able to draw on experience which they had acquired with the Porsche Ceramic Composite Brake (PCCB). The short-staple reinforced ceramic

material proved an extremely A water jet cuts the friction disk out of the ceramic plate at around 3,000 bar.

6 Porsche Engineering Magazine 02/2004 Porsche Ceramic Composite Clutch Drivetrain

Several layers of carbon fibre fabric are processed with carbon-rich resin to produce plate material, which is subsequently converted into carbon at approximately 800 degrees Celsius and then siliconized at 1,400 degrees Celsius. The individual disks are cut out of the result- ant ceramic plates by means of a high-pressure water jet.

The subsequent tests confirmed that these disks were now able to cope with the high levels of stress, displaying only a very slow rate of wear.

The driver comfort aspect also had to be taken into account. The dynamic ten-cylinder engine with its extremely low rotational mass made moving off with the necessary comfort a particular challenge for the

Porsche developers. The PCCC in the overload test on the Porsche test bench.

The synchronization of the manual The maximum thermal load for the Comprehensive tests on the test transmission was optimized so as disks made of carbon fibre-reinforced bench and extensive trials in the to require only low shifting forces. silicon carbide is over 1,400 degrees vehicle under extreme loads Celsius and is thus not a critical showed that the PCCC is able to at When tests carried out on the test factor. least match the service intervals of bench to examine misuse revealed conventional clutches. temperatures of over 800 degrees Lining carrier disks made of titani- Celsius in the ceramic friction um with rivetted-on sinter linings disks, it became clear that the were chosen for the driving disks. materials for all the components in This choice combines resistance to the clutch would have to be select- centrifugal forces and high temper- ed with corresponding care. atures with low weight and a subsequent low rotating mass.

Porsche Engineering Magazine 02/2004 7 Drivetrain Porsche Ceramic Composite Clutch

development which possesses excellent future prospects for high- stress applications in standard production vehicles, too.

The comprehensive experience which Porsche's engineers have acquired in the fields of composite ceramics, PCCC and series production can be applied in the development of the most diverse types of drives - particularly in the high revs range. Porsche Engineering offers this knowledge in the international arena. ■

The small diameter of the clutch disks enables a low position for the crankshaft.

The engineers have thus more than met the requirements for the clutch Technical information of the Carrera GT. Notwithstanding Type Two-disk dry clutch the fact that the costs are substan- External diameter 192 mm tially higher than that of a conven- Weight 3.5 kg tional clutch on account of the high- Materials Carbon fibre-reinforced silicon carbide ly involved production process and Transmission Maximum of more than 1,000 Nm the small quantity produced to Run-out speed Over 20,000 r.p.m. date.The PCCC trailblazes a line of

8 Porsche Engineering Magazine 02/2004 Body structure of the Carrera GT Body & Safety

Thoroughbred racing engineering for safe and enjoyable driving

Just like thoroughbred racing vehicles, the Carrera GT has a rolling chassis. Running gear, chassis, sub-frame, engine and crash structure are fully functional.

and the drive, which are normally The Porsche Carrera GT is high-tech incarnate. In performed by the body shell. In developing this vehicle, Porsche's engineers have contrast to the conventional body managed to integrate pure racing technology into a design featuring a large number of individual components, the mono- high-performance vehicle suitable for everyday use. coque is produced from a few As is customary in motor racing, the Carrera GT CFRP shell elements which are features a so-called rolling chassis. bonded together in high-pressure ovens.

Low weight, maximum torsional that the monocoque should be This solution promptly gave way to rigidity and a low center of gravity made of carbon fibre-reinforced the next difficult question: What were the main objectives addressed plastic (CFRP), as only fiber com- was the rear of the car to look like by the Porsche development engi- posites combine low weight with and how was it best to be connect- neers. As is customary in motor maximum rigidity to guarantee the ed to the monocoque? racing, the chassis is also the cen- desired characteristics of maximum tral component of the Carrera GT, performance, dynamics and safety. comprising monocoque, windscreen The monocoque fulfills all the struc- frame and roll-over structure. The tural functions, such as the transfer development team soon agreed of reaction forces from the chassis

Porsche Engineering Magazine 02/2004 9 Body & Safety Body structure of the Carrera GT

When the car is in use, the sub- frame is continuously exposed to sources of extreme stress in the form of heat, oil, moisture or road salt. Following extensive tests and theoretical analyses, the Porsche engineers were certain that the rear part of the car could be produced in carbon fibre-reinforced plastic. This was a revolutionary break- through, as up to this point the material had only been used in the aerospace sector or for structural and panel parts in motor racing.

The chassis and the bolted-on sub- frame are the key structural components, forming a torsionally and flexurally rigid unit – the Carrera GT's Sophisticated processing ture under operating loads and with backbone, as it were. They support of carbon fibers due regard to the worldwide safety the front and rear wheel suspension The structural parts are manufac- requirements by means of compre- and absorb the forces acting on the tured by means of an involved man- hensive FEM simulations. vehicle from the crash structures. ual process in so-called sandwich At the same time, they also support design. The monocoque consists of Depending on the given require- and serve as a bearing structure around 1,000 individual blanks. The ments, additional layers of up to for the panel components and the production process for each CFRP 20 millimeter thick honeycomb interior. component begins by placing car- material are placed on the inserted bon fiber mats impregnated with mats with adhesive films as packing An integral body frame is the norm synthetic resin (prepregs) in the between the CFRP outer layers. The in car manufacturing today. In con- respective production moulds. honeycomb material is made of alu- trast, the Carrera GT features a so- Resin type, fiber type, fiber orienta- minum or aramid paper, depending called rolling chassis – just like a tion and the thickness of the fabric on the component's intended func- thoroughbred racing car. The fully mats are dependent on the load tion. functional rolling chassis comprises range or area of application and the the chassis itself, sub-frame, drive, subsequent function of the compo- Additional layers of impregnated running gear and crash structures. nent concerned. Accordingly, these carbon fiber matting are then lami- parameters require to be defined. nated on. This leads to a substan- Porsche has obtained crucial infor- tial increase in the rigidity of com- mation on the behavior of the struc-

10 Porsche Engineering Magazine 02/2004 Body structure of the Carrera GT Body & Safety

So-called honeycomb material between the individual CFRP layers provides for additionally enhanced rigidity on components which are subject to particularly high levels of stress.

ponents which are subject to particularly high levels of stress.

To enable the attachment of additional components to the load-bearing CFRP structure - from simple screw connections to attachment points for the chassis or drive which are subject to high levels of stress – aluminum inserts are laminated into the structure and struc- turally bonded with the outer carbon fiber layers in an autoclave. Components are attached to laminated-on aluminum inserts. The Porsche engineers conducted in-depth investigations into the spe- Finally, the mould is sealed air-tight Despite their enormous capacity to cific electrochemical properties of with a foil, evacuated and subjected withstand stress, most CFRP parts the carbon fiber materials in con- in an autoclave to a pressure of 6 weigh up to 40 per cent less than junction with the metallic materials to 8 bar and – depending on the comparable conventional compo- commonly used in car manufactur- given requirements – to a tempera- nents, which means that the ing. On the basis of this knowledge, ture of over 180 degrees Celsius. Carrera GT sets new standards in they were able to develop special In the course of this process, the terms of weight. The entire mono- coatings or barriers which met the resin systems polymerize and bond coque weighs in at barely 100 kilo- high quality requirements for every honeycomb or inserts with the car- grams. type of application. bon fiber via the adhesive films.

Porsche Engineering Magazine 02/2004 11 Body & Safety Body structure of the Carrera GT

High level of safety as a result of carbon fiber composites Porsche's engineers opted for carbon fibre composites as the material for the Carrera GT's high-performance components, as this is the only material able to combine maximum performance and driving dynamics with minimum weight and maximum rigidity. As a result of Chassis, sub-frame and crash structures: Austenitic stainless steel absorbs the major part these properties, the high-tech fiber of the energy acting on the vehicle in a crash. also offers a very high standard of safety. The Carrera GT attains the rior to the high level attained by a ensure that the monocoque remains highest possible level of flexural modern coupé. free of any structural damage in the and torsional rigidity for a standard statutory tests. A rigid passenger production roadster. This outstand- The Carrera GT's safety concept is cell ensures the necessary survival ing overall rigidity is even far supe- based on the current requirements space. The major part of the energy in motor racing. It is designed to acting on the vehicle is absorbed

Front of rear Sub-frame Roof Monocoque center section

Wing Rear lid Front lid Rear wing Rear of rear center section

Front-end trim

Outer side section Door Roll-over bar trim

End panel Door sill

Prepreg autoclave, RTM, Prepreg autoclave, Prepreg-treated aluminum tooling, monolithic design monolithic design sandwich design monolithic design

Apart from the monocoque and sub-frame, numerous other components are also produced in CFRP.

12 Porsche Engineering Magazine 02/2004 Body structure of the Carrera GT Body & Safety

by the crash structures, which are made of austenitic stainless steel.

Porsche has examined the vehicle's crash behavior in extensive virtual tests. The engineers conducted extensive research in order to obtain an understanding of the overall system. In this context, suitable simulation tools were defined, detailed material structures were The frontal crash simulation calculation – here with 40% overlap – corresponds to the experiment. mapped in an FE model, material laws were evolved and simulations and experiments were systematical- Porsche's competence in CFRP The diverse modes of use for fiber ly compared at the key stages of In the course of developing the composites in the Carrera GT have the development process. In order Carrera GT, Porsche has examined provided Porsche's engineers with to examine the interaction of mono- CFRP and its properties in great an extensive knowledge of these lithic and sandwich materials in depth under the most diverse con- materials which enables them to combination with metallic materials, ditions. Aspects such as long-term offer competent solutions in all for example, each individual carbon and corrosion behavior, surface manner of areas relating to CFRP. fiber layer was mapped in a calcula- quality and crash properties have tion model. been examined in detail, calculated This makes Porsche Engineering and optimized for the Carrera GT. the right address when it comes to The engineers have optimized this developing carbon fiber compo- method to such an extent that the Porsche has also managed to nents – and not only in the automo- behavior of carbon fibers and steel develop the CFRP components for tive field. ■ in a crash can be calculated with a exterior and interior in a very high very good degree of correlation to quality with regard to appearance. experimental investigations.

Porsche Engineering Magazine 02/2004 13 Chassis Rehabilitation equipment

A wheelchair all set for adventure

Alber called on the engineers from Porsche Engineering for support in developing the chassis. The chassis specification for the Adventure placed the priority on a lightweight construction, comfortable suspension and an all-round attractive design. It was also important for the wheelchair to be easily dismant- lable and stowable in a mid-size car by one person without great effort.

In view of these requirements the engineers quickly opted for inde- pendent wheel suspension as is used in cars. Each wheel is provid-

The Adventure remains a reliable means of transport, even on difficult terrain. ed with full suspension and hydraulic damping. This ensures that the The Adventure wheelchair from the Ulrich Alber electric wheelchair remains stable company sets new standards in the field of electric and very comfortable, even on uneven terrain. The effective damp- wheelchairs. Sporting a modern design, it is modular, ing additionally benefits users who light, comfortable and safe. Porsche Engineering are susceptible to spasms trig- played an instrumental role in the development of the gered by vibrations. chassis. On the front axle the wheels are installed on two parallel wishbones. High curbs, cobblestones or Ulrich Alber, a company based in This ensures constant castor countryside tracks often mean the Albstadt-Tailfingen, Germany, which throughout the entire suspension end of the road for wheelchair specializes in rehabilitation equip- travel. The spring and damper ele- users. Previously, those electric ment, launched an ambitious proj- ment work together with a stabilizer wheelchairs which were able to ect to address the numerous prob- in a central case (extruded profile). navigate such barriers offered the lems in this area. The Adventure The stabilizer reduces tilt substan- user little comfort and safety. A was designed in just three years. tially on uneven terrain, ensuring further drawback was the heavy This electric wheelchair with full that the user feels safe and secure design of many wheelchairs, which suspension is suitable for indoor at all times. A rectangular tube meant that they could only be trans- and outdoor use. It is a reliable serves as a stabilizer which is ported in a special vehicle. means of transport, even in difficult adjustable to the user's individual terrain. weight.

14 Porsche Engineering Magazine 02/2004 Rehabilitation equipment Chassis

The front wheels are suspended on the inside on a one-armed fork. This delicate fork is fully in keeping with the design concept and safely transmits all the operating loads. The Porsche engineers arrived at this solution by mapping a non-linear calculation model of the wheelchair with user. This enabled precise prediction of the effects of the forces acting on the wheelchair when passing over an obstacle, for

The wheels fitted on two parallel trailing links are suspended on one-armed forks which trans- example. mit all operating loads.

The electric wheelchair features a Anyone who has pushed a super- trailing link at the rear. This link is market trolley will be familiar with attached to the rear wheel via a the way the trailing wheels block as a result of torsional vibration. Such an unpleasant situation can also apply to wheelchairs. Following comprehensive test runs at a test site which Albers set up especially for this purpose, the engineers opted for a light rotary damper based on an elastomer. This damper prevents vibration of the steering wheels at all speeds, without compromising the wheelchair's maneuverability or taking up any valuable space in the footwell.

Porsche Engineering Magazine 02/2004 15 Chassis Rehabilitation equipment

bayonet connection and establishes electrical contact with the wheel- hub drive in the rear wheels. The suspension and damping are visible here and are also continuously adjustable to the user's needs.

A non-linear calculation model of the wheelchair and user enables precise calculation of travel over obstacles.

Each wheel is provided with full suspension outstanding design. The Adventure and hydraulic damping. achieved the ranking "red dot: best of the best". Of 1,673 products, Steering is effected via different 381 received awards, with 33 mak- speeds of the drive wheels; the ing the "best of the best" category. front wheels steer in passive mode. The "red dot" is awarded annually This enables the wheelchair to turn by the Design-Zentrum Nordrhein- on the spot. The wheel hub motor Westfalen, Germany. ■ developed by Alber itself is particularly efficient, enabling the use of relatively small batteries. This, in turn, has a positive effect on overall weight, agility and range. The modular design enables batteries, Technical information wheels and seats to be removed Weight 96.7 kg from the chassis quickly and with- Max. load 140 kg out the use of any tools. Top speed 12 km/h Suspension travel front/rear 58/58 mm The new wheelchair concept has Range Up to 45 km already come in for recognition: The Climbing ability with load of 140 kg 18 % Adventure has received the "red dot Turning radius 0.88 m award: product design 2004" for

16 Porsche Engineering Magazine 02/2004 911 GT3 RS Complete Vehicle

Expertise in complete vehicle development

The development of high-performance derivatives requires in-depth expertise in the area of tuning and adapting the complete vehicle. Porsche's competence in this field is particularly evident in the 911 GT3 RS, which has been developed especially for motor racing.

Porsche has a long tradition of Porsche's all-embracing compe- After a period of more than 30 years, developing high-performance vari- tence in this area is illustrated par- Porsche decided in 2003 to build a ants based on existing vehicle mod- ticularly well by the example of the successor to the legendary Carrera els. Customer projects from this 911 GT3 RS. 2.7 RS (1972) and the 911 SC RS field are also playing an ever more (1984) as a limited edition. The aim significant role. The Audi RS2 and Mercedes-Benz 500E were developed together with Porsche, for example.

Developing a series model into a high-performance derivative is about much more than simply lowering the vehicle and improving performance by means of a harder chassis and spoilers. Safety requirements in particular mean that the entire vehicle has to be adapted to the increased power Tuning and coordination of the 911 GT3 RS were carried out in close collaboration between Motor Racing and Series Development. and enhanced driving dynamics.

Porsche Engineering Magazine 02/2004 17 Complete Vehicle 911 GT3 RS

was to develop a thoroughbred the 911 Carrera. The chassis was enhances guidance of the front high-performance variant of the also fully revised with regard to axle. This results in an even more 911 which could also serve as a spring rates, spring characteristic stable vehicle, particularly during homologation model for internation- and damper characteristics. As the heavy braking on race circuits. al GT motor racing. In addition to lowering of vehicles generally an optimum power-to-weight ratio, results in an undesired enlargement The dynamic performance potential the road variant was also to pos- of the wishbones' working angle, of the RS is only exploited to the sess technical refinements which specially developed wheel carriers full as a result of the combination could subsequently be deployed in are deployed on the 911 GT3 RS. of lower center of gravity, modified the racing version. The modified attachment points of suspension and damping, optimized these wheel carriers enable hori- stabilizer characteristic and a tailor- To ensure the desired enhanced zontal positioning of the wishbones made chassis geometry. The result- performance, the chassis, body, despite the lower position of the ant effect goes well beyond the engine, exhaust system, tires, aero- vehicle. This leads to a harmonious "lower and harder" formula. A par- dynamics and interior of the 911 camber characteristic over the ticularly detailed understanding of GT3 RS were modified and duly compression and rebound travel. the way in which the individual coordinated. This renders the vehicle more readi- measures interact is crucial to ly controllable in extreme driving achieving this result. Fully revised chassis geometry situations and results in noticeably In order to bring the 911 GT3 RS more precise steering. Lighter and safer: The body into shape for the race track, the To ensure an optimum power-to- vehicle's center of gravity was first The wheel carriers of the front axle weight ratio for the 911 GT3 RS, of all lowered, as a result of which incorporate a double clamp for the the bodyshell was made lighter than the RS is 30 millimeters lower than spring struts which further that of the 911 GT3, without compromising on safety in the process. Additional weight advantages are achieved by producing the wing and the front hood in Carbon/Kevlar. A standard lightweight roll cage offers the occupants protection in more ways than one. The cage additionally braces the attachment points on the body, thereby optimiz- ing the properties of the 911 GT3 RS's chassis and providing for more precise handling.

Special openings in the front section deliberately direct the exhaust air from the radiators over the vehicle.

18 Porsche Engineering Magazine 02/2004 911 GT3 RS Complete Vehicle

Here too, however, the interaction between individual components requires due consideration – the resonance intake system must be coordinated perfectly with the back- pressure hood.

The lively engine now generates 280 kW (381 bhp) at 7,300 r.p.m. from a displacement of 3.6 liters. The maximum engine speed is

The 911 GT3 RS possesses no lift, guaranteeing optimum driving stability. 8,200 r.p.m. The volumetric effi- ciency stands at 105.8 bhp. Drive and drivetrain dynamics which reduces the engine's pump are key to the car's character losses. Optimum aerodynamics The lightweight concept also In order to achieve optimum aero- extends to the engine. In particular, The connecting rods are made of dynamic behavior in accordance the rotating masses must be as titanium. A lightweight crankshaft with the enhanced performance, a minimal as possible. This is the which is plasma-nitrided for compromise has to be found bet- only way of achieving higher engine increased strength and pistons of ween the lowest possible lift at the speeds and increased power output reduced weight round off the light- front and rear axles and a low drag with the same displacement. weight engine concept. coefficient. The large rear wing provides the 911 GT3 RS with Porsche's engineers were able to The connection between engine and increased downforce at the rear reduce the weight of the valve drive transmission on the RS is estab- axle. In order to bring the down- by a total of two kilograms, for lished via a single-mass flywheel, force at the front axle into balance example, by using hollow camshafts which possesses a lower rotational and newly developed lightweight mass than a dual-mass flywheel. tappets. The tappets of the 911 Special control units take account GT3 RS now have a diameter of of the attendant parameters to only 28 millimeters and a curved ensure perfectly coordinated engine base. This so-called crowning of the management. base makes it possible to reduce the diameter, as the necessary sur- A specially developed back-pressure face contact between tappet and hood facilitates aspiration of the cam is retained. The valves are also engine. At high speeds, this hood produced in a high-strength, light- results in overpressure at the air weight material. A special valve pro- inlets, thereby facilitating air intake duces a vacuum in the crankcase by the engine and generating more The large rear wing provides the 911 GT3 RS with increased downforce at the power – up to 15 bhp at top speed. rear axle.

Porsche Engineering Magazine 02/2004 19 Complete Vehicle 911 GT3 RS

with this rear downforce, the engi- Tailor-made tires elements are covered in Alcantara, neers incorporated special open- The tires also require specific to offer adequate grip and prevent ings in the front section for the design in keeping with the vehicle's slipping. exhaust air from the radiators. As a enhanced performance and the result, the exhaust air from the radi- possible use on the race track. The Impressive performance data ators is deliberately directed over 911 GT3 RS possesses ultra high In transforming the 911 GT3 into the vehicle and the desired balance performance tires which permit the 911 GT3 RS, the specialists at is restored between the downforce higher lateral acceleration. Porsche modified numerous compo- at the front and rear axles. nents to ensure optimum safety and Interior durability in the face of the new The 911 GT3 RS as a whole does Naturally enough, the prime focus performance data. Tuning and coor- not possess any lift, resulting in with regard to the interior design of dination of the overall vehicle was excellent driving stability at high the 911 GT3 RS was on sporty ele- pursued in close collaboration speed. ments. The entire ergonomics have between Motor Sport and Series been geared to use on the race Development, in order to provide track. The 911 GT3 RS is fitted the vehicle with both the necessary with the statutory fire extinguisher racing characteristics and the and the seats are covered in a required practicality in everyday flame-retardant material. All haptic use. The power-to-weight ratio of the 911 GT3 RS now stands at 4.86 kg/kW. With a full tank of 90 liters of fuel, the car weighs 1,360 kilograms (2,998 lbs).

The 911 GT3 RS accelerates from 0 to 200 km/h (124 mph) in 14 seconds. The maximum speed is 306 km/h (190 mph). This high power output is transmitted via a close-stepped 6-speed manual transmission.

Porsche's comprehensive expertise is also available to Porsche Engineering's customers. Porsche is the only renowned manufacturer of high-performance vehicles to place

The entire ergonomics of the 911 GT3 RS has been geared to use on the race track. the full scope of its development competence at the disposal of other automobile manufacturers. ■

20 Porsche Engineering Magazine 02/2004 The new Porsche Insights

The new Porsche 911 comes in two variants

For the first time since 1977, Porsche is offering two new 911 models simultane- ously – the 911 Carrera and the 911 Carrera S. The sixth generation features an impressive combination of superlative engineering and uncompromising design.

The 239 kW (325 bhp) 911 Carrera the 911 Carrera. In "Normal" mode, is powered by a 3.6 liter horizont- PASM offers comfortably sporty The design of the new Porsche 911 ally opposed engine. The S version tuning of the shock absorbers, represents an uncompromising con- with a newly developed 3.8 liter while after pressing the "Sport" tinuation of the 911 story, – a engine has a power output of button a harder damper character- blockbuster which has now been 261 kW (355 bhp). 400 Newton istic is activated which supports a running for over 40 years. The new meters of torque catapult the particularly agile and sporty style exterior design – including a wider Smodel from 0 to 100 km/h of driving. In addition to PASM, a track and a more pronounced mid (62 mph) in 4.8 seconds. The 20 millimeter lower sports chassis section – lends the 911 an even Carrera requires exactly 5.0 sec- with mechanical rear differential more dynamic, clear-lined, powerful onds for this discipline. The maxi- lock is also optionally available for and elegant appearance. Other mum speed for the Carrera stands both models. striking features of the evolutionary at 285 km/h (177 mph) and for the design are the new circular head- Carrera S at 293 km/h (182 mph). The wheels and tires have grown in lights with additional separate head- format: The 911 Carrera model is lights at the front end, more pro- Both 911 models feature a newly now fitted as standard with 18J nounced wings, new double-arm developed six-speed transmission wheels in size 8J x 18 with 235/40 door mirrors, a modified joint style and a revised chassis which incor- ZR 18 tires (front) and 10J x 18 and an aerodynamically optimized porates active damping as standard with 265/40 ZR 18 tires (rear). rear spoiler. ■ on the S model. This chassis, which The Carrera S is fitted with 19" goes by the name of "Porsche wheels/tires in size 8J x 19 with Active Suspension Management" 235/35 ZR 19 (front) and 11J x 19 (PASM), is available as an option for with 295/30 ZR 19 (rear).

Porsche Engineering Magazine 02/2004 21 Special Development expertise

Design and testing working hand in hand for 30 years

It was back in 1974 that Porsche combined the areas of testing and design in Weissach. In so doing, the company established the basis for the "consolidated development center".

The Porsche Research and Develop- ment Center has been based in Weissach since 1971. All areas of work relating to trials and testing were first of all located here. The design area, which had been based in Zuffenhausen, subsequently moved to Weissach in the late summer of 1974. This established the basis for today's "consolidated design center".

Despite the enormous growth of the company over the past 30 years, the central approach to development has been retained. Develop-

ment resources have also been Summer, 1975: The areas of design and testing have been jointly housed at the Porsche Research and Design Center in Weissach for a year. established in Bietigheim and in Troy, USA, to complement the central Research and Development The full scope of development oper- Through Porsche Engineering, inter- Center. ations is covered at the central national customers are able to draw Research and Development Center, on the full scope of the company's Optimum networking and communi- from individual components to com- development expertise, from initial cation facilities for the roughly plete drives, from design studies to concept design through to series 2,500 technicians and engineers production-stage prototypes. production support services. ■ from the various fields of special- Development activities do not ization in Weissach are the guaran- always focus solely on cars, how- tee for innovative solutions. ever. Aircraft engines, fork-lift trucks, advertising pillars or electric wheelchairs are just some examples of development projects which have been carried out under strictest confidentiality for external customers .

22 Porsche Engineering Magazine 02/2004 Complete Vehicle · Styling · Body & Safety · Engine · Drivetrain · Chassis · Electrics & Electronics · Testing · Industrial Engineering · Production Support

We love: cars. We build: cars. We develop: cars and more. (And never stop thinking about: cars.)

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Address Porschestraße D-71287 Weissach Germany

Tel. +49 (7 11) 9 11-1 88 88 Fax +49 (7 11) 9 11-1 89 99

Porsche Engineering Services, Inc. 1965 Research Drive Troy, Michigan 48083 USA

Tel. ++ 1 248 524-0028 Fax ++ 1 248 740-5097

Email: [email protected] Internet: www.porsche-engineering.com

Editor Sabine Schröder Jens Walther

Porsche Engineering driving identities