The tale of the duck and the whale

1972 Porsche 911 Carrera RS 2.7

Porsche was eager to emphasize the connection between street usage and race cars and introduced the Porsche 911 Carrera RS 2.7 (RS for Rennsport) at the Paris Motorshow in October 1972, which would feature these improved aerodynamic components designed for the then-current 911 models. “We wanted to improve traction and handling with wide tyres on the rear axle because the greatest weight is found on the rear axle” Peter Falk explains on the official website of Porsche. For this, the development engineers took inspiration from Porsche racing cars. Fuchs, who made the wheels, forged 6 J×15 wheels with 185/70 VR-15 tyres at the front, with 7 J×15 with 215/60 VR-15 tyres at the rear. To accommodate them, the car’s body at the rear, around the wheel arches, was widened by 42 mm. This was combined with a firmer-tuned, lighter suspension system and thicker anti-roll bars, lightweight aluminum front beams, reinforced control arms, and cross-member reinforcement at the back.

The Porsche 911 Carrera RS featured enlarged bores, increasing from 84mm to 90mm, resulting in a displacement of 2687cc. It maintained the same valves and compression as the 2.4, allowing the engine to unleash 207hp to the rear wheels at 6300 RPM. In addition to aerodynamic and engine modifications, Porsche also focused on weight reduction. Thinner sheet metal, reduced glass thickness, and the removal of sound insulation were implemented. The interior of the 911 Carrera RS 2.7 ‘Lightweight’ (M471) was stripped down to the bare essentials. Elements such as the rear seat, carpets, clock, coat hooks, and armrests were omitted. At the customer’s request, lightweight bucket seats replaced the heavier sport seats. Even the Porsche emblem on the hood was glued on. The eventual weight of the lightweight version was approximately 960kg. The marketing and sales staff doubted the concept of a fully stripped lightweight Porsche 911, pointing to the extremely limited production of the Porsche 911R in 1967, with only 20 units leaving the factory. Alongside the initial lightweight (M471) variant, which saw the production of 200 units, a more comfortable version was introduced – the Touring (M472). Certain components that were removed from the 911S for weight reduction were reintroduced in this Touring conversion, resulting in a final weight of 1093kg. The first batch of the Touring comprised 300 units.

In 1971, Helmuth Bott, the head of Porsche’s vehicle development, convened his team in his office after the question arose as to why their customers could not compete with the BMW 2002s and the powerful Ford Capris on track. This issue was attributed to the sloping rear end of the Porsche 911, which acted as an airplane wing. As a result, the front end became lighter, providing little stability in fast corners. Efforts were made to find a solution aimed at minimizing the front lift of the Porsche 911. Allow me to tell you the tale of the duck and the whale.

Helmuth Bott’s team included Hermann Burst, Tilmann Brodbeck who had just graduated in aircraft technology and aerodynamics from the Technical University of Darmstadt and stylist Rolf Wiener. Brodbeck, who at the time owned a Fiat 850 Coupé 2+2 that he was fond of, as he mentioned in an interview with ‘Hagerty,’ exchanged it for a series II that came with a 5 hp performance increase and a little flick on the end of the engine cover. “I was astonished, it felt a lot faster, I knew it wasn’t possible with just 5bhp, so I asked the people at the Darmstadt wind tunnel if it could be the new engine cover – but they said it was just styling, nobody knew at the time,”. This experience prompted the development of the ‘ductail’ .

Who would have thought that finding a solution to a problem would give rise to an icon? Helmuth Bott, Hermann Burst, Tilmann Brodbeck, and Rolf Wiener had no idea. Various versions of a spoiler were crafted from sheet metal and wooden blocks to provide more stability to the Porsche 911. Initially, there was laughter about the design, which resembled the tail of a duck. However, Günter Steckhöning, an experienced racer, demonstrated the effectiveness of this spoiler: he achieved higher speeds and reported improved stability. With each iteration of the spoiler, the height was increased, resulting in an increase in speed and reduced air resistance for each iteration, until this gain in speed and resistance leveled off. Ultimately, an increase of 4.5 km/h was observed. To comply with safety standards for other road users, the tail was shortened to stay within the body lines of the car.

1972 Porsche 911 Carrera RS 2.7

Porsche was eager to emphasize the connection between street usage and race cars and introduced the Porsche 911 Carrera RS 2.7 (RS for Rennsport) at the Paris Motorshow in October 1972, which would feature these improved aerodynamic components designed for the then-current 911 models. “We wanted to improve traction and handling with wide tyres on the rear axle because the greatest weight is found on the rear axle” Peter Falk explains on the official website of Porsche. For this, the development engineers took inspiration from Porsche racing cars. Fuchs, who made the wheels, forged 6 J×15 wheels with 185/70 VR-15 tyres at the front, with 7 J×15 with 215/60 VR-15 tyres at the rear. To accommodate them, the car’s body at the rear, around the wheel arches, was widened by 42 mm. This was combined with a firmer-tuned, lighter suspension system and thicker anti-roll bars, lightweight aluminum front beams, reinforced control arms, and cross-member reinforcement at the back.

The Porsche 911 Carrera RS featured enlarged bores, increasing from 84mm to 90mm, resulting in a displacement of 2687cc. It maintained the same valves and compression as the 2.4, allowing the engine to unleash 207hp to the rear wheels at 6300 RPM. In addition to aerodynamic and engine modifications, Porsche also focused on weight reduction. Thinner sheet metal, reduced glass thickness, and the removal of sound insulation were implemented. The interior of the 911 Carrera RS 2.7 ‘Lightweight’ (M471) was stripped down to the bare essentials. Elements such as the rear seat, carpets, clock, coat hooks, and armrests were omitted. At the customer’s request, lightweight bucket seats replaced the heavier sport seats. Even the Porsche emblem on the hood was glued on. The eventual weight of the lightweight version was approximately 960kg. The marketing and sales staff doubted the concept of a fully stripped lightweight Porsche 911, pointing to the extremely limited production of the Porsche 911R in 1967, with only 20 units leaving the factory. Alongside the initial lightweight (M471) variant, which saw the production of 200 units, a more comfortable version was introduced – the Touring (M472). Certain components that were removed from the 911S for weight reduction were reintroduced in this Touring conversion, resulting in a final weight of 1093kg. The first batch of the Touring comprised 300 units.

The Porsche 911 Carrera RS 2.7 marked the very first Porsche to wear the name ‘Carrera’. The inspiration for the name was drawn from the Carrera Panamericana, a legendary (and highly perilous) Mexican road race that traversed from border to border in the early 1950s. In 1953, Porsche secured a memorable class victory with a Porsche 550 Spyder, followed by a third-place finish overall the year after. Subsequently, various powerful Porsche engines were already assigned with the ‘Carrera’ name. When a name was needed for the new top-tier 911, the newly designed lightweight Porsche stood out. ‘Carrera’ it read between the wheel arches on both sides in a color contrasting with the body paint, intersected by a broad stripe in the same color. This color scheme extended to the Carrera RS sticker on the ducktail and the Fuchs wheels, as well a thin line surrounding the car, for the lightweight conversion.

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