Porsche 959 | Sequential Twin Turbos | Four Wheel Drive | 1986-1989
Interestingly, the Porsche 959 started out as a Group B project before it became Porsche’s legendary supercar of the late 1980s. In 1981, Porsche’s head engineer Helmuth Bott wanted to expand on the 911 as well research and develop an all wheel drive system for Porsche. (edit, as per @that911’s input:) Another significant reason for the development of the 959 was to explore the limits of Porsche’s “incorrectly” placed rear engine. Bott chose Group B as the testing grounds for the car and used the racing program to accelerate development.
Most of the work at the start of development went into designing the all wheel drive system and the suspension to cope with all four wheels being driven. While mechanically the all wheel drive system wasn’t anything revolutionary, the ingenious component was the computer that controlled where the power would be sent. The computer did so via the PSK’s (Porsche-Steuer Kupplung, Porsche’s name for the all wheel drive system) clutch between the transmission and front differential and was smart enough to compensate for weight shift during acceleration and to adapt to different surfaces such as gravel, ice, or snow. At the time, this was the most advanced all wheel drive system on a production car. Porsche also employed use of an anti-lock braking system on the 959, using an existing ABS that was completely redesigned (caliper pictured above) due to complications involving the all wheel drive system.
Being Porsche, the design of the car was supposed to maintain the basic shape of a Porsche 911 while keeping the weight of the car down, along with the drag coefficient. The designers did an amazing job at all of this while adding an elegantly integrated rear wing and ending up with a drag coefficient of 0.32, in part due to the enclosed underbody design. While having a very strong and durable monocoque and drivetrain, along with the all wheel drive system and being packed with technology, the finished “Comfort” production car weighed in at 3,197 lbs (1450kg), with a “Sport” version that weighed just over 220 pounds (100kg) less.
The engine used was the 2.85L flat six that had been previously designed for use in the 935/78 Moby Dick race car. The engine consisted of an air-cooled block with watercooled heads that made use of 4 valves per cylinder and twin camshafts. The engine, helped by sequential twin-turbochargers made a very impressive 450 hp and 369 ft·lb of torque and, in the road car, was mated to a 6-speed manual transmission.
While Group B was mostly only a way to test the cars, the Group B 959s eventually had a few successful races, taking first place in Dakar in 1984, and finishing first, second and sixth in 1986. The focus was then moved to refining the 959 as we know it, a blisteringly fast yet elegant supercar. The first car wasn’t shipped until 1987 with a final price of $225,000, which would have bought you a Countach and a Tersarossa in those days. Even so, Porsche was still losing money on each of the 250 cars built for customers, with a total of 337 cars built including prototypes. Also interesting was Porsche’s refusal to meet emissions and safety standards of the United States, resulting in the US Customs Service holding Bill Gates’ 959 for 13 years until the “Show and Display” law was passed in 1999.
More important than the price, though, was the performance of the machine. The 959 Sport made it from 0-60mph in 3.6 seconds, in part due to the reduced turbo lag with the sequential turbo setup as well as the extremely smart and grippy all wheel drive system. The 959 continued on up to 100mph in around 8.5s and with a top speed of nearly 200mph, it was the fastest car in the world at the time. The 959’s one-off racing variant, the 961, won first in class and 7th overall in the 1986 24 Hours of Le Mans before catching on fire after an accident the following year. The 959, however, was the original high-tech supercar and remains a symbol of Porsche’s beautiful and brilliant engineering, with the technology developed for the 959 used on a variety of 911s in the years to come.
(Sources: ultimatecarpage.com (along with the pages on the Sport, Dakar and 961), Wikipedia, insideline.com)
(Source: racingengineering)