Opel Manta B 400 v1.0

The Opel Manta is a rear-wheel-drive sports coupé motor vehicle built by Opel from 1970 to 1988.

In 1979 work began on a rally-spec Opel. Both the Ascona B and the Manta B were used for this. Although the Ascona 400 model was the most successful of the two, largely due to better weight distribution, the fact still remains that the Manta 400 was a remarkable car.

Opel joined forces with German tuner Irmscher and Cosworth in Britain, to make the 400. Cosworth was given the task to develop a 16-valve 2-cam head for the CIH spec engine block, and Irmscher who earlier in 1977 and 78 had proven that they knew their way around an Opel building the i2800, was to design the exterior and interior of the cars. The results were not bad. Opel however had problems with the engine. The first idea of using a 2.0-litre engine and then using the 16-valve head from Cosworth simply did not give enough power. The problem was that the heads had already been built, so the heads were made to fit on the CIH type 4-cylinder engine block. So they built an unusual engine using a 2.0-litre engine block with an overbore and larger pistons, a crankshaft from the 2.3-litre diesel engine of same type (CIH) and ended with a 2.4-litre engine block. Mounting the 16-valve head on this gave a massive output, and the opportunity to make several tune-ups for the rally drivers.

Opel delivered the first 23 specimens in 1981 which were recognizable by the 2 slot front grille (1982, 83, and 84 models had 4 slot grilles). The cars were delivered as both street cars and factory tuned rally cars. The streetcars known as Phase 1 cars, were luxury versions of the known Manta B Coupé. Although all the changes to give the body more strength were still implemented, the cars were delivered with all kinds of exclusive packaging. Recaro seats with big Opel badges on the cloth, Irmscher leather steering wheel, and even front light washers were mounted. The cars were all delivered in Arctic White colour, with White Ronal lightweight 7×15″ alloys. The engine was fitted with a Bosch LE injection system and power output was 144 bhp (107 kW). The Phase 2 however was quite different. It had large extended arches front and rear made of materials such as carbon and kevlar to keep the weight down, lightweight doors, bonnet, spoilers and windows. The wheels were still from Ronal but now measuring 8×15″ front and 10×15″ rear. The engine output was 230 bhp (172 kW) using a set of 48 mm (1.9 in) DCOE style carburettors, and the cars could be delivered with different gearboxes from ZF and with different rear axle options like LSD. Phase 3 which is also a term used when talking about the i400s was not a factory tune-up. Many racers of the time had their garages tune up the engine even further. Some made it across the 300 bhp (220 kW) mark and even today, engines can be tuned to deliver just over 340 bhp (254 kW) still naturally aspirated.

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