The Sport version of Audi's sensational Quattro was launched in the autumn of 1983, three years after the original's unveiling at the Geneva Salon had taken the motoring world by storm.

It had a shortened wheelbase and was fitted with a new, lighter version of the five-cylinder engine boasting an aluminium block and a Twin-Cam 20-valve cylinder head, while anti-lock braking made its first appearance on a Quattro-equipped Audi.

Running on Bosch HI-Jetronic fuel-injection, the extensively revised engine developed a claimed 306bhp and gave this quite remarkable road car a top speed of around 155mph.

Audi built 214 examples of the Sport, though only 164 were actually sold to customers.

We are delighted to be able to offer Keith Edward's legendary 800bhp-plus, SWB Audi S1.

It was initially purchased by garage owner and rally driver Keith as a family road car but there were always lots of cars around and the Audi was eventually hardly used.

Passionately interested in motorsport, Keith...