One of the fastest and most spectacular MG cars ever built, the 6R4 Group B rally car was developed for Austin Rover by Williams Grand Prix Engineering. 6R4 stood for 6 cylinder, rear engine, 4 wheel drive. The 6R4 project was first revealed in February 1984 and scored its first rallying victory at the Gwynedd Rally in March 1985.
This car is chassis 001, the development prototype tested and raced by Tony Pond to prove the 6R4. It differs in many ways from the full Group B version, particularly in the aerodynamic package fitted and for having a slave V6 engine (actually a cut down Rover V8), as the V64V unit was still under design.
In May 1985 the full homologation Group B 6R4 was revealed. Fitted with a purpose-built V6, four overhead cam, 24-valve engine (V64V) mounted behind the seats, it delivered 410bhp. The engine drove all four wheels via a five-speed gearbox and a Ferguson-Formula viscous coupling epicyclic central differential, resulting in a 35/65% front/rear torque split. From a standing start, 60 mph could be reached in 4.3 seconds.
Sadly, the 6R4 was not sufficiently developed in time to make an impact on the international rallying scene before Group B regulations were changed to abolish such specialised machinery.
Technical details
Engine: V6 cyl, 2646cc
Top speed: not quoted
Power: 250 bhp
Coachwork: rally car
Price new: not quoted
Registration mark: A656 NJO