Issue 01/2005 Porsche Engineering Magazine Measuring without contact The dynamic behavior of the valve train is measured by laser vibrometry Great feeling A simulator can make it pos- sible that shifting forces of a gearbox can be felt even during the design phase. Harsh climate Porsche's climatic center is where the all-weather testing is carried out. Contents Porsche Engineering is a Porsche modular systems; we also take on Whether you require a general auto- Group subsidiary specializing in planning and implementation of mobile developer or specialized sys- contract development services. complete vehicles all the way to tem-provider, Porsche Engineering When contracted to support car series production. What makes our can bring you the best of both manufacturers or original equip- offerings unique ist our proven worlds. ment suppliers, we offer design and expertise as a volume vehicle man- development services, from individ- ufacturer. ual components through to complex Editorial Page 4 Complete Vehicle Chassis Drivetrain Electrics & Electronics Styling A real sense of the shifting forces Page 8 The 1:2 scale Cayenne Page 10 Double take on the 911 Page 5 Our expertise is based in Weissach If you would like to know more (Germany) with extensions through- about Porsche Engineering, please out the world: Troy, USA. Prague in send an e-mail requesting our the Czech Republic, or directly on- image brochure to the following Insights site with you. Wherever our compe- address: tence is required, it’s always [email protected] Prize awarded for use of Porsche Engineering. new materials – distinction for Carrera GT Page 19 More sporty, more power- ful and more confident – the new Boxster Page 20 Fresh air fascination – the new 911 Cabriolet Page 21 Body & Safety Testing Production Engineering Engine Industrial Engineering Valve Train dynamics: Measuring by laser Page 16 Special Porsche – on land Bracing climate and water in Research and Page 22 Development Center Page 12 Editorial Dear Readers, In the company’s climatic center we One of the other topics covered is try to simulate how vehicles, com- dynamics: as part of the engine ponents or materials behave when development, Porsche Engineering exposed to the most varied weath- uses laser vibrometry to investigate er conditions. This service can also the dynamics of the valve train, be requested from Porsche because only a perfectly-tuned Engineering. engine guarantees maximum per- formance with optimum fuel con- Very few people know that comprehen- sumption – and that doesn’t just sive climate control research is also apply to sports cars. carried out in Porsche’s Research and We wish you an enjoyable read, Development Center. The Editorial Team Before the current 911 went into production, it underwent the obliga- tory hot and cold tests. State-of-the- art technology has helped the new Carrera achieve outstanding per- formance and dynamics. In this issue we present a few of the sports car’s technical highlights. 4 Porsche Engineering Magazine 01/2005 Highlights 911 Carrera Complete Vehicle Double take on the 911 The current 911 is distinguished by outstanding performance and driving dynamics. The Porsche 911 has evolved into one of the world's most successful sports cars of the past 40 years. The sixth generation is continuing this long tradition: the outstanding performance and driving dynamics of the current 911 are assisted with the latest technology. The Porsche 911 is available in two versions with differing engine sizes: the Carrera, the standard version, has a 3.6 liter engine producing 239 kW (325 bhp) at 6,800 rpm; and the Carrera S has a 3.8 liter engine producing 261 kW (355 bhp) at 6,600 rpm. The new 3.8 liter boxer engine reaches its maximum torque of 400 Nm at 4,600 rpm. This per- formance power unit accelerates the Carrera S from 0 to 100 kilo- meters an hour in 4.8 seconds. Its The 3.8 liter engine has a power output of 355 bhp (261 kW) at 6,600 rpm, which brings a top speed of 293 km/h. The Carrera S can accelerate from 0 to 100 km/h in 4.8 seconds. top speed is 293 km/h. Porsche Engineering Magazine 01/2005 5 Complete Vehicle Highlights 911 Carrera Aerodynamic coefficients New six-speed transmission improved Because of the increased perform- The Porsche 911's new shape is an ance of the Carrera S, both 911 evolutionary step forward, not only coupés have been given new six- in its design but also in its aerody- speed manual gearboxes with namics. All coefficients have again increased torque capacity and been significantly improved in com- shorter gearshift travel, but without parison with its predecessor. For adding to the vehicle weight. example, the Carrera's drag coeffi- Tiptronic S, now further optimized cient dropped from Cd 0.30 to 0.28. in its gearshift program and quality, The cooling air channel at the front of Even more significant are the lift is still available as an alternative to the vehicle has been further optimized forces of 0.05 at the front and the new six-speed manual transmis- to reduce flow losses. 0.02 at the rear. These figures sion. make the Carrera a front runner ing – the variable ratio steering against the international competi- Rack-and-pinion steering with helps with a considerably faster tion. variable transmission ratio steering response. The driver's steering input is for the Cooling air losses minimized first time on the 911 Carrera by Active PASM suspension It was possible to reduce cooling rack-and-pinion steering using a For the first time, the 911 has an air losses mainly by modifying the variable ratio which particularly active damping system for the guidance system design. On the improves agility on winding roads. revised suspension. The PASM previous model, the extracted air In urban driving – parking and turn- (Porsche Active Suspension was expelled vertically downward in front of the front wheels. It is now guided directly to the wheel house and directed to the exterior of the vehicle through flaps. Cooling air throughput was increased by a total of 20 percent without increasing drag – which, at around 1.5 per- cent, was already at an extremely low level in comparison with the competition. For the first time, the 911 has an active damping system. The PASM consists of map-con- trolled dampers, a control module and two acceleration sensors. 6 Porsche Engineering Magazine 01/2005 Highlights 911 Carrera Complete Vehicle A new head airbag is integrated in the door side sill. In conjunction with the thorax airbag in the front seat back rest it provides a high level of protection against side impacts. Management), featured as standard In both the Normal and Sport pro- Head airbag underneath the on the 911 Carrera S, combines grams, PASM selects the required side window two chassis in one: one with equal damping rate for each individual The new 911 Carrera meets all re- measures of sportiness and com- wheel from a precisely co-ordinated quirements for passive vehicle safe- fort for long distances, and one map. The possible damper settings ty and offers exemplary side-impact entirely dedicated to sportiness for range from comfortable to decided- protection. A new head airbag is extreme driving. ly sporty. This ensures a gain in concealed in the door and, in con- active driving safety in all driving junction with the thorax airbag in The PASM system consists of map- situations with a noticeable improve- the front seat back rest, provides a controlled dampers with continuous- ment in the level of comfort. high level of protection against side ly adjustable damping force, a con- impacts. Together with the driver trol module and two acceleration Impeccable brakes and passenger airbags, the new sensors for detecting vertical move- In the case of the Carrera, rein- 911 has a total of six airbags. I ments of the body. Lateral acceler- forced four-piston fixed calipers as ation, steering angle, speed, brake well as perforated and internally pressure, engine torque and more ventilated 318 mm brake disks at are all read in via the CAN bus. The the front and 299 mm at the rear required program (Normal or Sport) (330 mm on all wheels in the case is selected via a button on the cen- of the Carrera S) guarantee ter console. extreme brake performance even under the toughest conditions. Porsche Engineering Magazine 01/2005 7 Drivetrain Shifting Force Simulation A real sense of the shifting forces The shifting forces are calculated in real time with the simulation software and replicated by means of servomotors on the gearstick. In the area of gearbox development every vehicle manufacturer strives to optimize gear-shift efforts. Porsche Engineering has developed a simulator that enables the shifting forces of any gearbox to be felt even at the beginning of the design phase. In the past, engineers almost exclu- sively used their experience from previous projects, along with their calculations, to define transmission qualities at the early development stage. However, it wasn't possible to truly experience the gearshift characteristics. This only became feasible once the prototype was built and operating. The test engineer can take up a position in a true to scale seat construction that replicates the driver's environment for a specific vehicle (here for example the 911 Carrera). 8 Porsche Engineering Magazine 01/2005 Shifting Force Simulation Drivetrain A special simulation software pack- acteristics experienced do not cor- age replicates gearshift operations. respond to requirements, the gear- In addition to gearbox-specific shift forces and travel can be rede- parameters, the dynamic effects of fined and optimized at the click of a the vehicle on the gearbox are also mouse.