TUNNING

Porsche Flachbau RS

The Flachbau body style (also known as the “slant nose”) and the Sonderwunsch program have been closely linked at Porsche for decades.

In the 1980s, the sports car manufacturer offered a spectacular modified version of the 911 Turbo (Type 930) with redesigned front wings and pop-up headlights. The design was based on the legendary Porsche 935, which had dominated endurance racing for years. Between 1982 and 1989, 948 examples of this modified version were sold. Even when later conversions are taken into account, the Flachbau models are still among the rarest variants of the 911 today. Curiosity and intrigue among those in the sports car scene and the media were certainly aroused when it was learned that Porsche had registered the model designations “Flachbau” and “Flachbau RS” with the European Patent Office in May 2025. Now the brand is revealing a secret: the reason for filing this patent was this complex transformation of the 911 GT2 RS (Type 991.2) with the Weissach package.

The multidisciplinary team - consisting of experts from the Sonderwunsch department, Style Porsche and development engineers from Weissach, Porsche Motorsport and Manthey - worked on the project for almost three years.

"The conversion to the model with a sloping nose proved to be very challenging, although we left the powertrain unchanged in agreement with the customer. Our goal was to reinterpret the iconic look of the 935 without compromising on safety, technology or roadworthiness," explains Alexander Fabig, Vice President Product Offer and Individualization at Porsche. "Thanks to comprehensive weight-saving measures, this unique car now weighs 31.6 kilograms less than before. That may sound unspectacular at first, but the 911 GT2 RS with the Weissach package is a sports car that has already been uncompromisingly optimized in terms of weight reduction."

Grant Larson, who has since retired, was responsible for the design of this Sonderwunsch project. The designer was also responsible for the modern interpretation of the 935 that Porsche presented in 2018 as part of its 70th anniversary celebrations.

“The new Flachbau RS is a modern, fitting reinterpretation of the iconic 935 Moby Dick design,” says Larson. “In addition to the lower front wings, the key feature is the stepped arrangement of the headlights with very narrow LED units.”

Inside, the sporty, high-quality feel of the front of the cabin is maintained, while the rear has been thoroughly stripped down to save weight. The Porsche Communication Management (PCM) system, audio components and most of the insulation and trim have been removed. Exposed metal elements in Grand Prix White, carbon fiber parts and deliberately exposed cables emphasize the racing car character. “Flachbau RS” lettering is embroidered on the carbon fiber seats, behind which a stylized version of the Nordschleife can be seen. A gold badge with the inscription Sonderwunsch and the embroidered words “Factory Unique 2026 | Flachbau RS” underlines its one-of-a-kind status.

The color scheme also plays with tradition and modern reinterpretation. “We combined Grand Prix White with parts painted in matt black and other parts with exposed carbon fiber,” continues Larson. “This creates a contrast, and the contrasting U-shaped element at the front is reminiscent of a design feature of the 935/78 in Martini livery - the famous ‘Moby Dick.’” The white shade was specially developed for this unique car. A historic 911 in Grand Prix White from the Porsche AG collection served as a reference.

The exterior reinterprets the Flachbau shape of the 935. The front wings are now lower and have grilles to reduce air pressure. Due to the new wing contour, the fuel tank flap and its mechanism underneath, as well as the front bumper, also had to be modified. Flaps from Manthey emphasize the aerodynamic performance of the front end. Instead of the standard round headlights, a new lighting system is used, with three very thin LED elements arranged in levels one above the other for the main beam, dipped beam and daytime running lights. Contrasting elements in black, exposed carbon fiber and Grand Prix White reflect the motorsport reference of the 935/78. Aero discs on the rear wheels and black brake calipers complete the overall picture.

The front splitter, the underbody structure, the rear diffuser and the carbon fiber aero discs improve aerodynamics and efficiency. The new rear wing with S-shaped struts is inspired by the 911 GT3 R Rennsport, but is around five centimeters higher on this car and can be locked in three positions. At a speed of 340 km/h and in the “High Downforce” setting, the Flachbau RS produces 554 kilograms of downforce on the rear axle.

Three test vehicles were built to carry out further validation tests. A test drive at Mendig Airport, 50 laps on the Nürburgring-Nordschleife and endurance tests in Weissach together simulated around 150,000 kilometers of customer use, especially for the rear wing. “On the Nordschleife, it immediately becomes clear how effectively the aerodynamic concept works,” says Porsche test driver Lars Kern, who drove the sports car on the Nürburgring. “The Flahbau RS remains extremely stable and precise even at very high speeds. This is exactly the kind of feedback needed to validate such a radically modified body design.”

 

Autonews