Any performance enthusiast would immediately recognize the significance of Porsche’s iconic slant-nose design and the legendary “Moby Dick” name.

The Porsche 935/78 “Moby Dick” was a radical 1978 Group 5 race car powered by a 3.2L twin-turbo flat-six producing up to 850 PS. Designed by Norbert Singer, its slant-nose front end, wide wheel arches, and massive white long-tail rear section created an unmistakable silhouette that inspired its famous whale-themed nickname.

The car won its debut at Silverstone with Jochen Mass and Jackie Ickx, but finished eighth at Le Mans after mechanical issues. Despite its brief racing career, “Moby Dick” went on to become one of Porsche’s most iconic and extreme race cars.

Now, nearly five decades later, Porsche is revisiting the spirit of “Moby Dick” with the one-off Flachbau RS, a bespoke interpretation of the 911 GT2 RS. Created through Porsche’s Sonderwunsch program in collaboration with Manthey, the unique supercar debuted at Monterey Car Week after nearly three years of development.

Based on a 2018 Type 991.2 911 GT2 RS with the Weissach Package, the Flachbau RS was commissioned by a Porsche enthusiast who wanted the 935’s unmistakable slant-nose design combined with modern performance and road legality. Despite the extensive transformation, Porsche retained the original powertrain.

The most obvious change is the dramatically reshaped bodywork. The front fenders feature louvers to vent the wheel arches, while a redesigned front bumper and ultra-slim, stacked LED headlights give the car a distinctive modern interpretation of the classic Flachbau shape.

Finished in Grand Prix White, the car also features exposed carbon fiber and matte-black accents. A distinctive U-shaped graphic on the hood pays homage to the Martini-liveried 935/78 that earned the “Moby Dick” nickname. Even the paint was specially developed using a historic Porsche from the company’s collection as its reference.

At the rear, the Flachbau RS gets a massive wing with S-shaped mounts inspired by the 911 GT3 R Rennsport. The manually adjustable wing can be set to three positions, with the high-downforce setting generating around 1,221 pounds of rear-axle downforce at approximately 211 mph.

Porsche and its customer also went to considerable lengths to reduce weight. Almost 32 kg were removed despite the original GT2 RS Weissach already being heavily optimized for weight reduction.

Inside, much of the rear cabin was stripped out. The Porsche Communication Management system, audio equipment, sound-deadening materials, and various floor coverings were removed. Exposed metal and carbon fiber replace conventional trim, while even unnecessary wiring was eliminated.

The result is a cabin that feels closer to a race car than a conventional road-going 911, while retaining the essentials needed for road use.

Despite being a one-off, the Flachbau RS underwent extensive validation. Porsche conducted digital crash and airbag simulations, structural analysis, aerodynamic CFD testing, and physical component testing before building the final car.

Three test vehicles were subsequently used for lighting and wind-tunnel validation, real-world road testing, and endurance testing. The development program included 50 laps of the Nürburgring Nordschleife and testing designed to simulate roughly 150,000 km of customer use on the rear wing.

The transformation also revives the Flachbau, or slant-nose, tradition that Porsche itself offered on the 911 Turbo in the 1980s. Inspired by the Porsche 935, that earlier factory special produced just 948 examples between 1982 and 1989, making genuine Flachbau models among the rarest 911 variants.

The new Flachbau RS takes that heritage and gives it a thoroughly modern interpretation, turning an already extreme 911 GT2 RS into a singular road-legal tribute to one of Porsche’s most recognizable racing legends.