Porsche - Racetrack to Road

Racetrack to Road

Technology transfer from racing cars to standard-series production is a tradition at Porsche—Christophorus has selected seven striking examples.

1953 Mid-engine
550 Spyder > 904

The 356 had been produced for two years already in Stuttgart-Zuffenhausen in 1952 when Porsche decided to send factory cars to races. So the engineers started designing a Spyder with an aluminum body. The heart of the 550 Spyder (photo) was its air-cooled, four-cylinder, boxer mid-engine located in front of the rear axle. The four overhead camshafts were powered by vertical driveshafts. Named after its designer, this Fuhrmann engine was superbly placed for driving dynamics, which in turn made the 550 Spyder exceptionally agile. With 81 kW (110 hp), it not only had a peak speed of 220 km/h but also promptly won the first race it entered, on the Nürburgring in 1953.

Ten years later this drive strategy showed up in the small-series 904 Carrera GTS. From 1969 to 1976, the Volks-Porsche 914 proved that a mid-engine sports car can offer enormous driving pleasure with a comparatively low output. The DNA of this open two-seater with a boxer engine in front of the rear axle has been successfully powering the Boxster since 1996.

1969 Active aerodynamics
917 > 911 Carrera

The Porsche 917 wrote a new chapter on aerodynamics in 1969. At first this twelve-cylinder racing car came in two versions: with an extended drag-optimized rear for top-speed racetracks, and with a short rear and low lift for courses with lots of curves. To reduce lift even more, the rear featured movable flaps, connected by a rod to the wheel suspensions. When the car turned into a curve, the flap extended over the inside rear wheel, which increased wheel load and stability—a mechanism as simple as it was brilliant and the first step on the road to active aerodynamics. This innovation celebrated its standard-series premiere in 1988 in the 911 Carrera (964, photo) in the form of a rear spoiler which automatically extended from the engine hood at 80 km/h.

The 911 has remained true to this principle to this day. Last year the new 911 Turbo received variable front and rear spoilers with the Porsche Active Aero­dynamics system (PAA).

1972 Turbo with bypass valve
917/10 > 911 Turbo

Porsche developed an open Spyder from the 917 Coupé in 1972 especially for the Can-Am series (Canadian-American Challenge Cup). Because the 917/10 (photo) initially lagged behind its powerful and high-capacity competitors, Porsche developed a twelve-cylinder turbo engine with 625 kW (850 hp). The challenge thereby was to control pressure buildup in order to make it suitable for a racing engine’s extreme load and speed changes. So the engineers decided to increase the charging pressure on the exhaust side rather than the conventional way on the intake side. Undesired excess pressure was sent past the charger via a bypass valve. The 917/10 dominated the Can-Am series with this engine. Soon this turbo technology appeared in standard-series production. In 1973 the prototype of the 911 Turbo (930) caused a sensation at the Frankfurt International Motor Show (IAA), and the standard version was presented one year later. With its charged three-liter boxer engine (191 kW/260 hp), this top 911 was one of the fastest standard-series cars in the world.

1984 PDK
956 > 911 Carrera

Porsche was already working on a double-clutch transmission back in 1964, and in 1979 it produced a study of a future sports car (995) which also featured a double clutch. In the course of further developing the 956/962 Group C racing car, the developers returned to the idea from the early 1980s of a manual transmission that didn’t interrupt traction. This technology was especially interesting in connection with turbo engines, making it possible to keep accelerating while shifting, which enabled constant charging pressures, not to mention shorter shifting times.

In 1983 the first trial of a power-shifting, electronically controlled spur gear was made—marking the birth of the Porsche-Doppelkupplungsge­triebe (PDK). One year later the 956 entered the 1,000-mile race in Imola for the first time with PDK. In 1986 the 962 C with PDK won the world championship race in Monza. However, the electronics and control capacities at the time were not yet able to meet the high demands for comfort in standard-series cars, so Porsche put the PDK on hold for a while.

In 2008, the 911 Carrera (997, second generation) was the first standard-series sports car to have a double-clutch transmission (photo). Today Porsche sells more than 90 percent of its 911s with PDK.

1983 Variable all-wheel drive
959 > 911 Carrera 4

In the early 1980s Porsche was working on a racing car for Group B. To optimize driving dynamics, engineers gave the 959 (photo) an all-wheel drive with an electronic continuously variable longitudinal lock. Depending on wheel load and friction values, drive torque was distributed over both axles. This design proved to be so successful (the 959 won the Paris–Dakar Rally in 1986) that Porsche then adapted it two years later for the 911 Carrera 4 (964).

This first 911 with all-wheel drive had basic traction distributed via a planetary transfer gear at a ratio of 31 to 69 (front to rear axle). A hydraulically activated longitudinal and transverse differential lock enabled the distribution ratio to be virtually continuously variable. To start up on slippery surfaces, the locks could also be activated manually via a rotary switch on the center console.

1998 Carbon fiber
911 GT1 > Carrera GT

The 911 GT1 drove to victory for Porsche in Le Mans in 1998 with a carbon monocoque. Carbon components combine extreme strength with low weight, but are very expensive. For this reason Porsche first brought a carbon chassis (photo) onto the road in 2003 in the Carrera GT super sports car. Porsche’s latest super sports car also utilizes carbon-fiber- reinforced polymer (CFRP). The 918 Spyder’s monocoque is produced by what is known as resin transfer molding. Woven carbon fibers are placed into a mold and injected with synthetic resin. The material is baked for around 20 minutes before being cured.

CFRP is appearing ever more frequently in street-legal racing cars like the 911 GT2 RS (997). It makes a component like the front hood more than two kilos lighter than its aluminum counterpart in basic cars.

2010 E-motor on the front axle
911 GT3 R Hybrid > 918 Spyder

The 911 GT3 R Hybrid (photo) served as a racing laboratory in 2010 and 2011, helping Porsche to develop its expertise for the subsequent use of hybrid technology in standard-series cars. The aim was to achieve maximum sportiness with the greatest fuel efficiency. In 2010 the car was powered by a 352 kW (480 hp) four-liter, six-cylinder combustion engine in the rear and two electric motors with 60 kW (82 hp) each on the front axle.

The GT3 nearly took a surprise victory at the 24-hour race on the Nürburgring in 2010. It held the lead until just about two hours before the finish, but then had to leave the race on account of damage to the combustion engine. Electric front-axle drive entered series production in the 918 Spyder in 2013. With a future-oriented drive strategy supplemented by the most sophisticated technology from the RS Spyder LMP2 racing car, this super sports car set a new record on the Nürburgring—it was the first standard-series car to complete a lap on the Nordschleife in less than seven minutes. With a total output of 652 kW (887 hp), the 918 Spyder consumes an average of only 3.1 liters per 100 kilometers in the New European Driving Cycle (NEDC).

Ferry Porsche’s credo remains unchanged: “Racing has to enhance series production.”