Porsche - Top Secret

Top Secret

As the physical manifestation of future concepts and tech­nological strokes of genius, prototypes are as indispensable as they are confidential. Some are ahead of their time or just too bold, but they are never useless. Every Porsche is informed by the creative spirit in which technology and art unite in a symbiosis that’s not always ready for series production.

Porsche 924

World record car: With the 924, Porsche broke new ground in 1976. As a timely response to the energy crisis, the attractively priced and economical four-cylinder sports car was intended to appeal to potential new customers. Porsche wanted to go in new directions in terms of marketing, too, and planned to draw attention with a high-speed world record drive. The goal of an average speed of over 250 km/h over a distance of 10,000 miles required a Porsche 924 optimized for long-distance rec­ords. The result: instead of the standard 92 kW (125 hp), the turbocharged world-record four-cylinder put out a splendid 184 kW (250 hp). The aerodynamics also received special attention. After extensive wind-tunnel testing, the drag coefficient was an outstanding Cd 0.268, which enabled a top speed of 280 km/h. Shortly before the planned record-breaking drive in July 1977, the world-record attempt was put on ice for strategic reasons. Instead of ripping around the high-speed oval of Nardò, the fastest 924 of all time rolled into the newly founded Porsche Museum.

Years: 1976/77
Engine: Four-cylinder turbo
Displacement: 1,984 cc
Power: 184 kW (250 hp)
Weight empty: 980 kg
Top track speed: 280 km/h

Porsche 984

Sports two-seater concept car: As a study for a future vehicle concept, between 1984 and 1987 the Porsche Development Center in Weissach worked on a compact, lightweight, and aerodynamic roadster. The project was inspired by a development job previously undertaken for the Spanish automaker Seat. As a small and relatively inexpensive sports car in the price range of 40,000 German marks, the Porsche 984 was designed to appeal to a young, sporty clientele. The development objective was primarily focused on dynamic driving characteristics, to be achieved through low driving resistance rather than massive engine power. Low fuel consumption was also defined as a development objective. A drive concept with an air-cooled two-liter, four-cylinder rear boxer engine and an output of 88–110 kW (120–150 hp) was aimed at emphasizing the technological distinctiveness of the model. A convertible version with an innovative folding hard-top was envisioned, as was an all-wheel-drive model for motor racing. The sales crisis precipitated by the plummeting dollar in 1987, however, put an early end to the 984 project.

Years: 1984 to 1987
Engine: Four-cylinder boxer
Displacement: 1,984 cc
Power: 99 kW (135 hp)
Weight empty: 880 kg
Top track speed: 220 km/h

Concept Car Type 995

Research car: Commissioned by the Federal Ministry of Research and Technology, in 1978/79 Porsche developed a concept for the construction of a future sports car. The development objectives for the four-seater Type 995 concept car focused in particular on fuel economy, safety, and noise emissions. The engineers in Weissach used a Porsche 928 as the technological basis for the research prototype. Special features of the concept car included a five-speed double-clutch transmission in conjunction with two low- consumption gas engines. Plans envisioned a high-compression three-liter V8 engine with automatic cylinder de­activation as well as a 2.2-liter four-valve, four-cylinder alter­native. The gear-shifting of the double-clutch transmission was electronically controlled without letting up on the gas, which contributed to the high efficiency of the drive system. In combination with a lightweight, aerodynamic aluminum body, the calculated consumption came in under 9 liters per 100 km. In addition to a comprehensive package of passive safety measures, an optimized anti-lock brake system enhanced active driving safety.

Years: 1978 to 1979
Engine: V8
Displacement: 3,000 cc
Power: 96 kW (130 hp)
Weight empty: 1,290 kg
Top track speed: 200 km/h

Porsche 959

C29 aerodynamics study: At the Frankfurt International Motor Show in 1983, Porsche presented a high-performance vehicle that would provide an impressive demonstration of the brand’s innovative drive: the “Group B” study. The production-ready version of the concept known as the Porsche 959 underlined the technical expertise of the company in 1985. Powered by a 331 kW (450 hp) boxer engine with ­water-cooled cylinder heads and bi-turbo sequential charging, the car topped the 300 km/h (186 mph) barrier with playful ease. The electronically controlled chassis, the program-controlled all-wheel drive, and the aerodynamically optimized body broke new ground for later Porsche sports-car generations. As the predecessor of the Porsche 950, the Type 959 C29 repre­sented the beginnings of this ambitious project. It was used for exten­sive wind-tunnel testing in 1982, which resulted in a low Cd-value of 0.31 paired with an optimal lift coefficient. The special characteristics of the C29 include the rear wing integrated in the bodyshell, the smooth transition from the windshield to the A-pillar, and the aerodynamic plastic underbody cover.

Years: 1982
Engine: Six-cylinder boxer bi-turbo
Displacement: 2,849 cc
Power: 331 kW (450 hp)
Weight empty: 1,450 kg
Top track speed: 315 km/h

Porsche 989

Concept car: With Porsche in the midst of an economic downturn in the late 1980s, it was decided in 1988 to begin development on a new model line with a project named 989. As a four-door “family sports car” or “Porsche for more than two,” the front-­engine V8 sports sedan with rear-wheel drive was to hit the market by 1995 and target a new market segment. But even during the initial project phase, development costs for the technically sophisticated four-door rose to improbable heights, making it impossible to keep the purchase price below 100,000 German marks. When the price calculation ultimately topped 150,000 German marks and the envisioned annual production quantity of 15,000 units could not be achieved economically, the supervisory board stopped the project in January of 1991. The efforts were not entirely in vain, however; many of the ideas and detail solutions found their way into future Porsche models such as the 996 type series of the 911.

Years: 1991
Engine: V8
Displacement: 4,200 cc
Power: 257 kW (350 hp)
Weight empty: 1,572 kg
Top track speed: 279 km/h

“Project: Secret!” in the Porsche Museum
From September 17, 2014, to January 11, 2015, the Porsche Museum will present the special exhibition “Project: Secret!” with never-built studies, unknown concept cars, and camouflaged prototypes from Porsche over the decades. A total of fourteen cars will be on display, as will miniatures from the Porsche archive and films showing testing.

Look & feel

Whether it’s driving behavior, aerodynamics, or accident progression—with state-of-the-art computer simulations, Porsche can represent it all on a computer screen. Uwe Schneider, head of overall vehicle development, testing, and quality, explains why true prototypes still have a future even in the computer era, and sheds light on the intelligent interaction between digital and real-life testing.

Mr. Schneider, why, in this age of constantly improving computer simulations, are there still driving prototypes?
Today vehicle development without the use of digital tools is unimaginable. That saves us a lot of time throughout the entire development process. Nowadays we can successfully simulate every part on the computer, and then we crash the parts on the screen as well. Nevertheless, in the future, too, the evaluation of actual vehicles will include driving tests.

So no early retirement for crash-test dummies?
No. I have to disappoint you there. We must also take into account the rising complexity of the vehicles. Just consider the variation in the drive system and the chassis, the increasingly numerous assistance systems, and not least the big future topic, the “connected car.” And to develop and secure all of these systems, the number of prototypes should in theory actually rise.

In theory?
Using computer simulations, we can at least keep the need for hardware—that is, real prototypes—at a constant level. The simulations have the inestimable advantage that we only have to build the digital prototypes once and can then use them as many times as necessary. That means the tested components have a much higher level of maturity, which represents exceptional savings potential in terms of time and costs.

Master of simulation and prototypes: Uwe Schneider is Porsche’s head of overall vehicle development, testing, and quality

So software versus hardware is only an apparent contradiction?
The key is ultimately the intelligent interaction of digital and real prototypes. It was the only way we could develop the super sports car 918 Spyder in record time. But simulation does have its limits. Only in a real prototype do we see how the vehicle reacts under real-life conditions. And for every Porsche, those real conditions include use at the limits of performance, such as on the racetrack. So every Porsche is put through its paces on real asphalt. Ultimately, it’s the lap on the Nürburgring that counts. And of course, the prototype also has to pass the endurance test. No simulation, no matter how good, can determine the wear on the vehicle after 150,000 kilometers on real roads and testing grounds.

How many prototypes did you have in operation for the new Macan model line?
In the Macan development project, we used about 190 prototypes. This number can vary upward or downward depending on whether we can take parts from the toolbox and the degree of newness of the vehicle.

Is the developer still moved by gut feelings?
Absolutely. At the end of the day, you have to experience that sports-car feeling. That applies to the developers as much as to every Porsche owner. You have to sit in the prototypes to know and experience whether the functions and the aesthetics work. That’s absolutely a part of the developer’s profession.

By Dieter Landenberger
Photos by Rafael Krötz