Porsche Carrera 6

Although officially called the 906 Coupé, the latest addition to Porsche's racing division was quickly given the nickname Carrera 6, continuing the tradition of awarding this prestigious label to the Zuffenhausen-based brand's most successful models in memory of Porsche's heroics in the famous Carrera Panamerica race over the previous decade. The Carrera 6 not only won the new Sport class, but also the Prototype class.

In the 1965 European Hill Climb Championship, the Porsche 904 Spyder, nicknamed "Känguruh" and driven by Gerhard Mitter and Anton Fischhaber, was regularly overtaken by the Dino Ferrari 206 of Ludovico Scarfiotti. The Porsche drivers constantly complained about the handling of their car and it was decided to build a new one urgently for the end of the season. 

The new Spyder was created in a few weeks and debuted on 25 August at the Ollon-Villars hill climb in Switzerland, giving this chassis the name "Ollon-Villars" Spyder. The 1965 championship was lost to Porsche, but the racing department now had an excellent basis for what would become the 906 Coupé, or Carrera 6.

A new era  

The man who orchestrated the advent of this car, considered to be the first Porsche of the modern era, was none other than Ferdinand Piëch, Ferry Porsche's nephew, who appointed him Director of Research and Development. In this capacity, he was also responsible for the racing activities of the Zuffenhausen-based company. Among his many projects, hill-climbing was particularly close to his heart, as hill-climbing enjoyed great international prestige at the time. In the meantime, the Fédération Internationale Automobile had issued new regulations for 1966. 

In the Grand Touring category, which Porsche had won four times in a row, it was now mandatory to produce 2,500 examples of a car in order to obtain homologation. This made it financially unaffordable for a small manufacturer like Porsche, and with renewed energy Porsche entered the new Sport class, which was relaunched that same year. This category, in which only 50 cars are produced, makes it possible to produce, on a less expensive budget, racing models that are closer to Prototypes than to GTs. So after the recent setbacks in the European Hill Climb Championship, Porsche turned with great ambition to the Sport category of the World Sports Car Championship.

Tubular chassis 

Its racing debut lived up to expectations, as the Carrera 6 won its class at the 24 Hours of Daytona (Hans Herrmann-Herbert Linge) and then went on to win the renowned Targa Florio (Willy Mairesse-Herbert Müller). These successes were followed by numerous class victories: Sebring, Nürburgring, Mugello, Brands Hatch, Zeltweg, which enabled him to win the 1966 World Championship in the Prototype under 2 litres and Sport below 2 litres categories... In order to save time and reduce cost for its construction, the Carrera 6 took over several mechanical elements from the 904 GTS, such as the beryllium brakes with ATE-Dunlop double-piston calipers, as well as the hub carriers and wheels supplied by Lotus. The main innovation was the frame structure, which was completely load-bearing and consisted of a multi-tubular latticework of circular steel tubes. The company "Karrosseriewerk Weinsberg" was responsible for its construction, and engineer Wilhelm Hild was seconded from Zuffenhausen to oversee its production. The bodywork is made up of removable elements moulded in glass fibre reinforced polyester resin.

An engine from the 911 

A total of 65 "Carrera 6's" were produced, including 52 with the original chassis, nine 906 E prototypes with the 6-cylinder fuel injection engine (225 hp) and four 906/8 prototypes with the 8-cylinder 2.2-litre engine (275 hp). For the 24 Hours of Le Mans, an LH version with extended frame was developed; 4.60 metres long, weighing 635 kg and capable of 300 km/h. The 6-cylinder engine of the 906 was derived from that of the standard 911. To save weight, the block was made of Elektron, while the cylinder heads were made of Silumin and the cylinders of aluminium with titanium connecting rods. The weight of the original flat-six is reduced from 200 to 143 kg. It delivers 210 bhp at 8,000 rpm (compared to 130 bhp for the 911) with a maximum torque of 20.1 kg at 6,000 rpm. The single-disc dry clutch and the transmission is complemented by a self-locking limited-slip differential type ZF.