The Manta 400 achieved FISA homologation under the Group B regulations on the 1st March 1983, after some difficulty in convincing the FISA that the required number of cars had been completed.
Opel employed renowned engine builders Cosworth to design the competition engine, the first starting point was solidity and therefore Cosworth utilised the Opel Record diesel cylinder block, before proceeding to fit a steel crank, steel rods and Cosworth pistons, and a cylinder head from Opel’s aborted Formula 2 circuit racing campaign. The car was homologated into the ‘up to 2500kgs’ class which had a minimum weight limit of 860kgs. This meant that the engineers could embark on a major weight saving exercise resulting in the car being equipped with Kevlar doors, bonnet, spoilers and bootlid, in the search for lightweight even the door and boot hinges were made from aluminium.
The Manta 400’s first event was the Tour de Course on the 5th May 1983, with driver Guy Frequelin, although the car did not complete the event going out on the 6th stage after a piston failed, the problems were short lived though as he and the car went on to win that year’s French Championship a feat they repeated in 1985.
The 1983 season saw the Manta 400s experiencing some top 5 places and also a number of non finishes. The highlight of the season was the 3rd place on the RAC Rally behind the two Audi Quattros.
1984 saw Rothmans withdraw from sponsoring Opel and as this accounted for 45% of the previous year’s competition budget, international events were carefully selected. 1985 again saw a carefully selected international campaign, whilst back at home the much hyped rivalry between Russell Brookes' Andrews Heat For Hire Manta and Jimmy McRae's AC Delco Manta, ensured it would be an entertaining year. The RAC Open Rally Championship saw Russell Brookes just beat Jimmy McRae to the title, whilst both held off the Peugeot 205 T16's and the Audi Quattro's.
1986 saw Opel announce plans to develop a 4wd car (The Opel Kadett S4, to compete under the planned Group S regulations), leaving the International scene a bit quiet. On the home scene Russell Brooks took the Manta 400 to 2nd overall on the Open Championship and Austin McHale take 1st overall on the Irish Tarmac Championship.
Debut at the end of the 1985 Open Championship campaign in the hands of Jimmy McRae who drove it to a very respectable 6th overall on the RAC Rally in the AC Delco livery. For 1986 the car passed into the hands of Russell Brooks who used the car on both Tarmac and Gravel events, taking 2nd place overall in that year’s Open Championship.
Engine : four-cylinder, 2.42ltr, in-line, longitudinally mounted in the front of the car, twin overhead camshafts, four valves per cylinder, 275 bhp
Induction : Twin Webber Carbs, Normally Aspirated