In the beginning......Austin Rover rejected a front-mounted V8/RWD design because the driver couldn't see the front of the car. This was a good decision. One of only a few.
AR went for something that combined (theoretically) the benefits of Audi (4WD) and R5 Turbo (mid-engined). The Metro's powerplant was also to eschew the fashionable nonsense of forced induction. This would mean zero turbo lag and everything would be so much simpler and more reliable. But what to fit? Having rejected the Honda V6, the only obvious solution was the 3.5 litre Rover V8. That wouldn't fit in the back....unless you chopped off two cylinders and welded it back together! Sorted! A new Rover V6 then, fitted with a purpose made crank, Rover Vitesse racing internals and Weber carbs - it gave 250bhp.
Throughout '84 the car appeared at national rallies as the team developed the homologation specification. This work (including wider track, longer wheelbase & enhanced aerodynamics) improved the car to such a degree that the 6R4 won the Feb '85 Skip Brown Cars Gwynedd Rally. Get in!
In May '85 a revised 6R4 was unveiled. It had a new engine (purpose-built 3 ltr TC 24V 90 degree V6, producing 250bhp in 'Clubman' form or approaching 400bhp in 'International' tune) and revised aerodynamics. Suspension travel was skillfully increased by four inches by welding box extensions on top of the turrets. This enabled fitment of the latest Michelin tyres (developed for Audi & Peugeot). The package worked, with victory on the 1985 Autofit Argyle Stages. Huzzah! The car was now being readied for it's WRC debut at the 1985 Lombard RAC Rally.
Incidentally - AR's other big decision against trend was to build the car as a 'ready to rally' kit. Owners had to carry out a minor degree of final assembly prior to racing. The £40,000 'Clubman', with the simple addition of harnesses and fire extinguishers, was 'ready to rally', and Ken Wood took delivery of his car on a Thursday, and with Golden Wonder sponsorship paint barely dry, won the 1985 Sprint Tyres Trossachs Rally two days later. Wunderbar! This was the first ever rally victory for a 'Clubman' Metro 6R4, and happened 6 days before the car was actually homologated. During August to October 1985, Austin Rover built 200 MG Metro 6R4s, successfully homologating the car into Group B.
At the Nov '85 Lombard RAC rally, Tony Pond finished third behind two Delta S4s. Brilliant! This, though, was the best result that the 6R4 would take at WRC level. Plagued with bad reliability, as the team tried to make up for their ever-increasing power disadvantage to turbocharged rivals, it wasn't until the '86 1000 Lakes Rally in September that the 6R4 achieved another WRC finish. In the end, the drivers were driving at 8/10ths to preserve their cars and enable a finish. The latter half of the season saw improving fortunes, but no wins.
On international and national rallies, however, the Metro 6R4 was achieving better results as the cars failed less frequently under less punishing conditions. Didier Auriol won the 1986 French National Championship. David Llewellyn won the 1986 Circuit of Ireland Rally. All told, the Metro won 5 championships during the '86 season.
Ultimately, though, the car was too little, too late. It took 5 yrs to get from drawing board to track, by which time turbos had become the way to go. FISA banned international Group B from 31st December 1986.