Porsche 911 Carrera RS 2.7 – the year of the ducktail
The racing plan that became one of the great road-going sports car classics.
Porsche needed a lighter, faster 911 for the racetrack. The result was the 1973 Carrera RS 2.7: a homologation model with a larger engine, a spartan interior, and a rear spoiler that looked unfamiliar at first—and then became immortal.
By Lars EkströmEditor-in-chief · Vintage cars and automotive historyTranslated from Swedish with the help of AI.
At the Paris auto show in October 1972 stood a Porsche with an odd-looking trailing edge on its engine lid. The body was familiar, but it had grown wider over the rear wheels, and the Carrera name ran along its sides in large letters. The little upturned edge at the rear would soon earn a nickname that outlasted both the auto show and the racing season: the ducktail.
The car was the 1973 Porsche 911 Carrera RS 2.7, a production sports car from Porsche in Stuttgart-Zuffenhausen. RS stood for Rennsport. Here, the racing connection was more than a selling point: the model was to give Porsche a homologated platform for continued competition with the 911.
Five hundred cars became more
The starting point was the requirement to build at least 500 examples for Group 4 homologation. Porsche initially planned a run of exactly that size. Customers, however, responded faster than cautious sales forecasts had anticipated. The first 500 were already sold by the fall of 1972, and according to Porsche's historical records, production ended at 1 580 cars.
Among those behind the work were development engineer Peter Falk and engine chief Hans Mezger. The task was to make the 911 more powerful without losing the advantage of a small, light car. The air-cooled flat-six received a larger bore, increasing displacement to 2.7 liters. Mechanical fuel injection remained part of the formula.
The Carrera name drew on Porsche's earlier racing successes in the Carrera Panamericana. But the RS was no nostalgic special edition. It was a tool for the next chapter, and the project also spawned the considerably more race-focused Carrera RSR.
Thinner sheet metal, fewer comforts
The most uncompromising road-going version was called Sport and carried equipment code M471. Today, it is often called the Lightweight. Among the items removed were the rear seats, clock, armrests, and some sound insulation. Simple door panels and lighter seats made the cabin feel more workshop than lounge.
The Touring, M472, restored much of the interior trim and comfort that customers knew from the 911 S. It became the more popular choice. The distinction matters when discussing an RS: two cars with the same engine and the same characteristic profile can differ markedly in weight and specification.
The pursuit of lower weight also included thinner materials in parts of the body and thinner glass. For those building the cars, lightweight engineering was not about a single dramatic invention, but about many small savings that together made a difference.
The ducktail, on the other hand, was impossible to miss. Hermann Burst and Tilman Brodbeck were among the engineers behind the aerodynamic work. The spoiler reduced rear lift while also helping supply air for engine cooling. Together with the front spoiler, it made the car better equipped for high speeds. The wider rear fenders also made room for wider rear wheels: the shape served a specific need.
Speed demanded respect
In a contemporary test in auto motor und sport, issue 5 of 1973, the lightweight RS version accelerated to 100 km/h in 5.8 seconds and reached 245 km/h. Those were remarkable results for a road car that still looked like a fairly compact 911. The magazine also highlighted its unusual combination of race-level capability and usability on ordinary roads.
That should not be mistaken for a design that had become forgiving in every situation. The engine still sat behind the rear axle. The load over the rear wheels helped traction, but the weight distribution made the driver's throttle inputs important in corners. In his technical history of the 911, Paul Frère describes how chassis development, tires, and aerodynamics progressively improved the model's behavior without erasing its fundamental character.
Ventilated disc brakes all around were part of the package. The RS was therefore not simply a more powerful engine in a stripped-down body, but a balance of acceleration, braking ability, grip, and stability. Our editorial team has not driven the car; the driving impressions here are based on published tests and technical histories.
The collector car behind the decals
Today, a genuine Carrera RS 2.7 is an internationally sought-after collector car. Its price depends heavily on specification, documentation, originality, and restoration history. A modified standard 911 can look convincingly similar, but it does not share the same origins.
For buyers, the chassis number, factory records, and the consistency of the engine and body with the as-delivered specification therefore carry considerable weight. Even a beautifully restored car needs scrutiny beneath the paint: lightweight components and original details are an essential part of the story.
Perhaps that is why the ducktail still resonates. It is not just a recognizable silhouette, but the legacy of an engineering effort in which every kilo and every stream of air had a job to do.
Sources
- Porsche AG, 50 years of the Porsche 911 Carrera RS 2.7 – ‘Germany’s fastest sports car’ (2022)
- Paul Frère, Porsche 911 Story (2006)
- auto motor und sport, auto motor und sport, nr 5/1973 (1973)
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