How the ducktail spoiler improves speed by 4.5 km / h

The spoiler of the 911 Carrera RS 2.7, known as the ‘duck tail’, has become an icon of design and aerodynamics

The first people to look suspiciously at the back of that Porsche were the ones responsible for the sale. They were supposed to release 500 copies of the 911 RS 2.7 and didn’t have them all with them. In fact, they thought they could not convince more than a hundred customers. It was at this time that the name Entenbürzel or ‘duck’s tail’ arose, because of the
resemblance the spoiler had to the water bird.

“Yeah, of course that wasn’t a compliment,” he says with a laugh.
Tilman Brodbeck. The aeronautical engineer joined Porsche in October 1970, when he was 26 years old, and together with Hermann Burst designed this already legendary car part.

“At the time, the 911 and many other cars had a very distinctive design: they were flat at the bottom, domed at the top and tapered toward the back,” explains Brodbeck. “This kind of shape generates lift.” Indeed, this air-generated lift would have prevented the 911 RS 2.7 from reaching the cornering speed that its engine and chassis would allow.

Engineers quickly realized
of the negative consequences that would have that termination of the rear part in the advantages of the car. An argument that would eventually also convince sales and design experts.

The wind tunnel revealed that problem. The solution was to add an aerodynamic element that can counteract the buoyant force generated. With a preliminary spoiler designed from wire and thin metal sheets, in just two days of testing
managed to reduce the lift coefficient Cz by as much as two thirds, until it reaches 0.08.

At the same time, the Cx value was improved and the top speed increased by 4.5 km/h to 240 km/h, an impressive figure for the time. It may not seem like much, but for a 911 with the last name ‘RS’ it’s something special. We must not forget that in the competition everything is often decided in hundredths of a second. The ‘duck tail’ offered so many benefits that even the most critical gave their arm to spin.

“In the end, the 500 vehicles needed for the homologation of the 911 Carrera RS 2.7 in Group 4 were sold faster than expected,” 79-year-old Brodbeck now recalls. Indeed, Porsche fans loved that spoiler and making fast laps on the tracks. And that aerodynamic element became an absolute novelty for road cars. Thus the ‘duck tail’ was born, which appears with number 2238704 in the German patent register of August 5, 1972.

Source: La Verdad

Ida

I am Ida Scott, a journalist and content author with a passion for uncovering the truth. I have been writing professionally for Today Times Live since 2020 and specialize in political news. My career began when I was just 17; I had already developed a knack for research and an eye for detail which made me stand out from my peers.