Porsche, turbocharging and the 911 – A brief history
At the 1973 IAA Frankfurt motor show, a silver prototype on the Porsche stand attracted much attention, not least due to its extraordinary appearance. From its engine cover extended a distinctive rear spoiler, with air intake louvres and edged by a thick rubber lip. Visually, it was reminiscent of the 911 Carrera RS 3.0, which had just come onto the market, but the badges on the rear wheel arches made it clear that this was an entirely different model: ‘Turbo’ was the motif that from that point forward would literally create a new legend in the sports car world.
Hidden beneath the dramatic rear spoiler was technology that quickened the pulse of even long-standing Porsche owners and enthusiasts: a three-litre flat-six engine with a turbocharger, developing 280 hp, a top speed over 160 mph and the supreme performance of a pure-bred racing machine. And that is what it essentially was, too.
Inspired by its motorsport programme, engineers at Porsche already had been researching ways to increase engine power for a number of years. Indeed, in 1969 the company built a flat 16-cylinder, 6.0-litre, naturally aspirated ‘Can-Am’ racing engine which produced 770 hp. The engineers calculated that in eventual 7.2-litre form, 880 hp was possible, but it never raced. In fact, it barely even ran in a car for Porsche had another engine on the test bench that rendered it instantly obsolete: a turbocharged version of the 5.0-litre ‘flat-12’ from the 917 Spyder was already delivering 900 hp; in time, it would become one of the most powerful racing engine of all time with 1,200 hp.
And thus, the Porsche relationship with turbocharging began. Following two consecutive championship titles in America’s thrilling, unlimited Can-Am racing series, Porsche applied its hard-won turbocharging know-how to the 911. The results would change high performance road cars forever.
Coincidentally, a 2.0-litre turbo flat ‘six’ from a 911 had been tested on the bench also in 1969, but it was not until early 1973 that road trials began with a 2.7-litre engine boosted by a single turbocharger. It was in this form that the car made its public debut as a ‘concept’, shown at the Frankfurt show in September of that year. Maximum power was quoted as 280 bhp, with a 160 mph plus potential top speed. The body was that of a 3.0 RS, albeit with huge ‘turbo’ graphics emblazoned on the rear haunches. Wealthy driving enthusiasts around the world clamoured for it, despite the imminent OPEC fuel crisis.
Undeterred by the pervading political environment in the Middle East, Porsche forged ahead with the car’s development, and when the production car appeared at the 1974 Paris motor show the specification had evolved. It now featured an engine with a cubic capacity of 3.0-litres, enlarged to bolster off-boost performance, with a claimed 260 hp at 5,500 rpm and 343 Nm at 4,000 rpm. A new, stronger gearbox handled the torque, but featured only four-speeds, and there was no boost gauge in the cockpit: then company boss Ernst Fuhrmann, believed well-heeled customers would not need to know the workings of its star propulsive feature in practice. It had cost Porsche $2 million to develop the car into a production reality, but the motoring press were dumbfounded; Britain’s Motor magazine called it “The finest driving machine you can buy”.
There had been considerable internal debate at Porsche as to what sort of car this new ‘super 911’ should be. Some felt it should be a road-racer in the mould of the previous and contemporary RS models, and indeed, the Turbo was required to sell a minimum of 400 units so that it could be homologated for the new Group 4 sports car rules. But Fuhrmann insisted the character of the Turbo – quiet, relentless, enormous power – lent itself to a true high performance GT with every creature comfort Porsche could conjure, and at a premium price tag. This ‘turbo template’ has been followed for every generation of 911 Turbo since.
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