There are rare cars, and then there are cars that exist at the intersection of three separate obsessions. The 1986 Porsche 911 930 RUF BTR ‘Flachbau’ currently heading to auction through Car & Classic’s second Collector Edition sale is exactly that: part factory Sonderwunsch, part RUF engineering statement, part Turbo Kraft fever dream. Finished in Prussian Blue Metallic over a matching blue leather interior, it is one of the more quietly ferocious things to emerge from 1980s Germany. It has subsequently been made considerably more ferocious still.
What the BTR Was
To understand this car, you need to look at what RUF was doing in the early 1980s. When Alois Ruf Jr. set his engineers to work on the BTR (the name standing for Gruppe B, Turbo, RUF), the goal was nothing less than building the fastest accelerating production car in the world. Using the Porsche 930 Turbo as a foundation, RUF bored the 3.3-litre flat-six out to 3.4 litres, fitted Mahle pistons, installed camshafts borrowed from the 935 race car, and paired the whole assembly with a larger KKK turbocharger. The result was 374 bhp, modest by today’s standards, but enough in 1984 to win Road & Track’s “World’s Fastest Cars” contest by a ten-mile-per-hour margin over everything Ferrari, Lamborghini, and Porsche could put forward. The BTR was, for a moment, the fastest accelerating production car on Earth. That status only changed when RUF built the CTR ‘Yellowbird’.
In 1981, Germany’s official TÜV body had granted RUF Automobile GmbH full manufacturer status, a distinction that separates RUF from every other tuner and makes its products, technically and legally, cars in their own right. The BTR was the first model to carry a proper RUF VIN. Somewhere between 20 and 30 were built from bare chassis; an unknown number were converted from customer-supplied donor cars. Records, as is characteristic of the era, are incomplete.
The Flachbau Factor
The Flachbau body (flat build in German, known in English as the Slant Nose or flatnose) began life not at Porsche, but with independent tuners like RUF and Kremer in the 1970s, who drew direct inspiration from the 935 endurance racer. Porsche eventually formalised it as a factory Sonderwunsch (special order) option, producing approximately 948 examples of the 930 Turbo in Flachbau configuration between 1981 and 1989. The slanted nose, pop-up headlights, and faired-in front end gave the car an unmistakably motorsport-derived aggression. It was, in every meaningful sense, a 935 for the road.
Of those 948 factory Flachbau 930s, only three are believed to have passed through RUF’s Pfaffenhausen facility for a full BTR conversion. Three. The combination of the Flachbau body and the BTR powertrain treatment is, in any meaningful sense of the word, vanishingly rare.
This Particular Example
The car being offered through Car & Classic began life as a standard, non-Flachbau factory Porsche 930. It was subsequently converted to full RUF BTR specification by an independent specialist, acquiring the Flachbau transformation, the RUF five-speed gearbox, and the characteristic visual identity of the BTR in the process. The conversion work is believed to have been carried out by Gary Borman at Exclusive Motorcars in Upper Montclair, New Jersey. Previously registered in the United States, the car also features a steel sliding sunroof, Vintage Air climate control, electric power steering, and the iconic 930 “Tea Tray” rear spoiler. It currently resides at a specialist in Stuttgart. Then someone decided that 374bhp was not enough.
The car has since been treated to a $150,000 engine build by Turbo Kraft, reportedly producing approximately 680bhp. This is no simple tune: the flat-six has been taken out to 3.45 liters, fitted with a GT3 crankshaft running a 76.4mm stroke for additional torque, and the whole assembly rebuilt to a specification that reportedly cost as much as a new 911 GT3 to commission. Supporting that power output is a full Elephant Racing chassis enhancement package, a company well regarded among air-cooled 911 devotees for the quality of its suspension and handling work.
To put the figure in perspective: the standard BTR made 374bhp. This car makes 680bhp. Through the rear wheels. In a body that was originally designed around 300 bhp. The original RUF BTR motor is retained and offered for separate negotiation, so the car’s history is intact regardless of which direction a future owner takes it. The odometer shows 30,831 miles. It presents in very good condition with light signs of use, commensurate with a car that has been driven rather than merely stored.
The Rest of the Sale
The RUF BTR ‘Flachbau’ headlines the Porsche contingent, but it is far from alone in the catalogue. Car & Classic’s curators have assembled a collection that spans from a 1920s hot rod Bentley through to a 2018 Porsche 911 GT3 991.2 Manthey Racing Coupé, the latter representing the perfect modern counterpoint to the Prussian Blue machine at the top of the bill. The Manthey-prepared 991.2 GT3 brings its own credentials as one of the most thoroughly developed track-day Porsches of the water-cooled era.
Beyond the Porsches, the sale includes a 2019 Ferrari Monza SP2, one of just 499 produced, last serviced in December 2025 at 114 kilometers, dry-stored since new, and still wearing its original Pirelli P Zero tyres. It is as close to new old stock as any Icona series Ferrari is likely to be. There is also a 1985 Lamborghini Countach LP5000 S, one of just 321 built between 1982 and 1985, making it rarer than either the Quattrovalvole or 25th Anniversary editions, and a 1937 SS 100 Jaguar representing the pre-war end of the spectrum. In total, over £10 million worth of collector cars across 39 lots.
Available Now
See the official listing on Car & Classic
Car & Classic’s Collector Edition 2 auction is open for viewing and pre-bidding now, with lots closing online at 5:50 pm GMT on Saturday, 21 March. Full catalogue details and bidding registration at carandclassic.com.
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