The arrival of the BTR marked the beginning of RUF as a manufacturer in its own right, establishing itself as the most highly regarded of Porsche tuning firms.

The BTR was inspired by the FIA Group B regulations of the time, using a 930 Turbo as a basis with which to produce a sportscar that was then successfully tested by journalists against the fastest products of Ferrari, Lamborghini and Porsche.

The BTR was regularly regarded as the fastest accelerating road car at the time, performance that was only beaten when RUF produced the legendary CTR ‘Yellowbird’.

The BTR utilised a Turbo engine bored to 3.4 litres and then fitted with Mahle pistons, 935-type camshafts and a larger KKK turbo; these modifications resulted in a power output of 374 bhp.

Various other modifications to the car included RUF suspension, a half-roll cage, RUF brakes and a RUF five-speed gearbox.

Only three BTR Flatnoses are believed to have been produced by RUF, this example being one of 948 930 Turbo Flatnos...