The Metro 6R4

One of the fastest and most spectacular Austin Rover cars ever built, the Metro 6R4 had only a superficial relationship with the standard production Metro car. Developed for Austin Rover by Williams Grand Prix Engineering. Named 6R4 after its configuration: 6 Cylinder, Rear wheel drive, 4 wheel drive.

The car benefited from extensive aerodynamic testing to improve downforce. The addition of the various wings gave the car a distinctive and functional appearance.

The Metro 6R4 was built to comply with the international Group B silhouette regulations for rally cars in the 1980s and is fitted with a purpose built V6 four overhead cam 24 valve engine. This is mounted behind the seats and drives all four wheels via a five speed gearbox and a Ferguson Formula viscous coupling epicyclic central differential, giving a 35/65% torque split. At the time, the four wheel drive system was by far more advanced than the rudimentary system used in the contemporary Audi. In full Group B spec the engine produced 410bhp, enough to get to 60mph in 3.2 seconds.

The 6R4 project was first revealed in Feb 1984 and scored its first rallying victory at the Gwynedd Rally of March 1985 with Tony Pond and Rob Arthur. The same car competed at the Lombard RAC Rally in November of the same year finishing third behind two Lancia Delta S4s. The car was officially still being developed so these were very respectable results.

Group B Banned After Fatal Crashes

Tragically Group B was banned half way through the 1986 season due to deaths and injuries in the Portuguese rally. In 1987 the format was changed to restrict engine power to 300bhp and limit the use of exotic materials.

The Metro 6R4 was essentially obsolete. As a Group B rally car it wasn’t able to compete and the 200 road going versions (built to allow the 6R4 entry to Group B) were sat unsold at a compound in Cowley.

Austin Rover deliberated with authorities to allow the 6R4 to be used on national rallies. While they eventually succeeded, one condition was to limit power to no more than 300bhp. This became the “Clubman 300” spec car.

Austin Rover managed to sell all 200 cars in less than a year, although many were bought at a significant discount.

“I know it’s an ugly beast, but the 6R4 is easily the best rally car I’ve ever driven. Enormous power with four-wheel-drive traction was a brilliant combination, but the transmission also brought other advantages in grip, stability and braking. Aerodynamics performance, too, was an area where the car was a pioneer, as other manufacturers had always believed rallying speeds weren’t high enough for wings to work”

Tony Pond – Professional Rally Driver

Austin Rover’s Group B Supercar Arrives Too Late

The Metro 6R4 was a very good idea in principal.

1. Deliver a worthy rally car to generate the same excitement as it’s predecessor the Mini Cooper.
2. Attain international coverage for success across the various Group B events.
3. Sell the homologated road cars and hopefully some of this exposure would help sales of the ordinary Metro.

Unfortunately, the car arrived at the very end of Group B. Had Group B gone on, it’s impossible to say whether the Metro 6R4 would have done well. It had an issue with turbo lag, which the other teams in Group B had already worked around.

The Jaguar Engine Connection

The engine was thought to be one of the first purpose designed for a rally car (most engines were heavily developed road car engines). This engine was then used in the Jaguar XJ220 Supercar, where it was twin turbocharged – the infamous test bed was this XJ220 engined Transit.

The Jaguar XJ220 had a similarly difficult launch. The British car industry must have thought this market was cursed – for a time at least.

More interesting information on the Metro 6R4 can be found on 6R4.net