Porsche 959

The Development of the 959 (originally called the Gruppe B) started in 1981, shortly after the then-new company Managing Director, Peter Schutz, took his office. Porsche's head engineer at the time, Helmut Bott, approached Schutz with some ideas about the 911, or more aptly, a new 911. Bott knew that the company needed a sports car that they could continue to rely on for years to come and that could be developed as time went on. Curious as to how much they could do with the rear engined 911, Bott convinced Schutz that development tests should take place, and even proposed researching a new all wheel drive system. Schutz agreed, and greenlit the project. Bott also knew through experience that a racing program usually helped to accelerate the development of new models. Seeing Group B rally racing as the perfect arena to test the new mule and its all wheel drive system, Bott again went to Schutz, and got the go ahead to develop a car, based on his development mule, for competition in Group B.

Porsche began with an engine they already had, and moved on with development from there. The powerplant, a twin turbocharged boxer six engine, with an air cooled block and water cooled heads displaced 2.85 total litres, about half a litre less than a contemporary 911 engine. The motor had originally been developed for the "Moby Dick" race car, then was redeveloped slightly for the short-lived Porsche Indy Car and several other projects before being "tweaked" a last time for use in the 961, the 959's racing counterpart. The water cooled cylinder heads combined with the air cooled block, 4 valve heads and sequential turbochargers allowed Porsche to extract 450 hp (340 kW) from the compact, efficient and rugged power unit. The use of sequential twin turbochargers rather than the more usual identical turbochargers for each of the two cylinder banks allowed for smooth seamless delivery of power across the engine RPM band, in contrast to the abrupt on-off power characteristic that distinguished Porsche's turbocharged engines of the period. It has been speculated the engine was capable of over 600 horsepower if fully tuned. The engine was used, virtually unchanged, in the 959 road car as well.

In an attempt to create a rugged, lightweight shell, Porsche adopted an aluminium and Kevlar composite for body use along with a Nomex floor as opposed to the traditional steel that was normally used on their production cars. The vehicle's light weight (2917 pounds) gave astounding performance:

0-60: 3.6 (3.5 for the u.s version)
0-100: 8.3
0-125: 12.7
0-140: 19.0
0-1/4 mile: 11.8s @119 mph
Top Speed: 198+ mph

Porsche also developed the car's aerodynamics which were designed to increase stability, as was the automatic ride height adjustment that became available on the street car (961 race cars had fixed suspensions). Its "zero lift" dynamics were a big part of keeping it drivable. The 959 also featured Porsche-Steuer Kupplung (PSK) which, at the time, was the most advanced all wheel drive system ever used in a production car. Capable of dynamically changing the torque distribution between the rear and front wheels in both normal conditions and slip conditions, the PSK system allowed the 959 to have the adaptability it needed both as a race car and as a "super" street car. Under hard acceleration, PSK could send as much as 80% of available power to the rear wheels, helping make the most of the rear-traction bias that occurs during such instances. It could also vary the power bias depending on road surface and grip changes, helping maintain sure footedness at all times. The magnesium alloy wheels were unique, being hollow inside to form a sealed chamber contiguous with the tire and equipped with a built-in tire pressure monitoring system.

The 1983 Frankfurt Motor Show was chosen for the unveiling of the Porsche Group B prototype. Even in the waning hours of October 9th, finishing touches were placed on the car to go on display the next morning. When the curtain was drawn the next morning, the Group B car became an instant celebrity. After the first two prototypes, the bodywork was modified to include air vents in the front and rear wheel housings, as well as intake holes behind the doors. The first prototype modified like this was code named "F3", and was destroyed in the first crash test.

The street version of the 959 debuted at the 1985 Frankfurt Motor Show as a 1986 model, but numerous issues delayed production by more than a year. The car was manufactured in two levels of trim, "Sport" and "Komfort", corresponding to the race version and the street version, respectively. First customer deliveries of the 959 street variant began in 1987, and the car debuted at a cost of $225,000 USD per unit, still less than half what it cost Porsche to build each one, production ended in 1990. In total, fewer than 300 cars were built and the total number (which hovers around 250) includes both 959 street variants and 961 race variants as well as at least 4 prototypes Porsche built during development. 226 of the cars built were street legal (in Europe) and were sold to consumers. At least one 959 and one 961 remain in the Porsche historic hall in Stuttgart, Germany.

The 959 was not street legal in the United States prior to 1999 when the "Show and Display" law was finally passed, although an unknown number were imported via the "grey market" during the late 1980s as show pieces. During the model's development, Porsche refused to provide the United States Department of Transportation with the four 959s they required for crash testing, and the car was never certified by the NHTSA for street use in the U.S. With the passage of "Show and Display" the crash test requirements were removed and importation of the 959 was allowed, assuming the car could meet with the local emissions standards that would have existed as of 1987. The 959 can be fitted with a catalytic converter and a rechipped computer which will allow it to meet those emissions requirements. However most owners refuse to modify their 959s, and the cars remain as collection pieces. While the initial selling price was $230,000, it is agreed that today, one of these cars would be worth upwards of a million dollars.

The lessons learned from the 959 in terms of engine management, aerodynamics, suspension tuning, and four wheel drive were what enabled the production life of the 911, once thought to be nearing obsolescence due to the extreme rearward placement of the engine, to be extended to the present day with no end in sight. In this way, the 959 project more than paid for itself many times over, and owners of new Porsche 911s can, to a large degree, benefit from the great strides forward made by this technological tour de force.

When Porsche began development of the 959, it looked towards Group B racing as a road-racing laboratory with which to develop technology for production cars. When Group B became focused on rallying events, however, Porsche felt the relevance to production cars was greatly reduced, and the goal of the 959 project shifted to frank state of the art, cost is no object technological innovation.

In 1984, however, three 911s modified to 959 specifications (due to the requirement that Group B cars be based on production cars with at least 200 built) were used in the Paris-Dakar Rally, with Jacky Ickx the prime motivator. By 1985 the 959 rally variant was ready, however it was a disappointing start: all three cars failed to finish. But in 1986 the 959 finished 1-2, erasing the disappointment of '85. The 959 was never seriously considered for a Group B Rally season; the cost of completing a full season far outweighed any technical information gained.

1986 was also the year that the racing variant, the 961, made its debut at the 24 hours of Le Mans, finishing first in class and 7th overall. It returned in 1987, but failed to finish after a spin while in 11th place. Thus ended the career of the 961.

text and images Porsche AG

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