Porsche celebrates 30 years of Turbocharging

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 280bhp, a top speed over 258km/hr 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, 880bhp 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 280bhp, with a 258km/hr 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.