Opel Manta 400

Opel Manta 400

The Opel Manta 400 is one of the most significant and rarest homologation specials produced by a German manufacturer. Built in a strictly limited run of 245 units between 1982 and 1984, the Manta 400 was created for one purpose: to homologate a competitive rally car for Group B international rallying. The result was a road car that was far removed from the modest family coupe on which it was based, offering genuine competition-derived performance in a package that remained street-legal.

The engine was the Manta 400's defining feature. Based on Opel's CIH (Cam In Head) engine family but extensively reworked by Cosworth Engineering, the 2.4-liter 16-valve inline-four produced 275 horsepower in road specification — a remarkable specific output for a naturally aspirated four-cylinder of the early 1980s. The Cosworth-developed cylinder head featured four valves per cylinder, twin overhead camshafts, and a high-compression ratio that demanded premium fuel. Bosch K-Jetronic mechanical fuel injection provided fuel delivery. In full rally specification, with turbocharging, the engine could produce over 400 horsepower.

The conversion from standard Manta B bodyshell to 400 specification was carried out by Irmscher, a well-known Opel tuning partner based in Remshalden, Germany. The transformation was comprehensive. The rear bodywork was modified with flared wheel arches to accommodate wider wheels and tires. A prominent front air dam and rear spoiler improved aerodynamics and high-speed stability. The front featured driving lights integrated into the bumper. The overall effect was aggressive but purposeful, clearly identifying the 400 as something far more serious than a standard Manta.

The chassis received significant upgrades. Ventilated disc brakes on all four wheels replaced the standard car's mixed disc/drum arrangement. The rear axle was located by a Watts linkage rather than the standard Manta B's trailing arm setup, providing much more precise rear axle location under hard cornering and braking. Stiffer springs, gas-filled dampers, and thicker anti-roll bars completed the suspension upgrades. The ZF 5-speed manual transmission featured a close-ratio gearset with the characteristic 'dog-leg' first gear pattern favored in competition applications.

Inside, the Manta 400 was relatively spartan compared to luxury sports cars of the era but well-equipped for a homologation special. Recaro sport seats, a leather-trimmed steering wheel, and comprehensive instrumentation including an oil pressure gauge and oil temperature gauge were standard. The interior trim was functional rather than luxurious, befitting the car's competition origins.

In competition, the Manta 400 proved highly effective. Works rally cars, campaigned by drivers including Henri Toivonen, Guy Frequelin, and Jimmy McRae, scored numerous victories in national and international rally events. The car was particularly competitive in Group B events on tarmac, where its rear-wheel-drive layout and high-revving engine could be used to devastating effect by skilled drivers. On gravel, the lack of four-wheel drive put it at a disadvantage against the Audi quattro and Peugeot 205 T16.

The Manta 400 also enjoyed considerable success in circuit racing. In the British Saloon Car Championship and European Touring Car Championship, Manta 400s were competitive against more powerful machinery thanks to their light weight and excellent handling balance. The car's motorsport career extended well beyond the Group B era, with privateer teams campaigning Manta 400s in national rally championships throughout the late 1980s and into the 1990s.

With only 245 road cars built, the Manta 400 was rare from the outset. Survival rates have been impacted by the car's competition purpose — many were converted to rally specification and subsequently crashed, cannibalized for parts, or simply worn out. Genuine road-specification survivors in good condition are extremely rare and highly sought after by collectors of homologation specials and Opel enthusiasts.

Today, the Manta 400 is recognized as one of the most important Opels ever built and a significant piece of Group B rally history. Values have risen substantially as the collector market has embraced 1980s homologation specials. The car represents a fascinating era when manufacturers built road cars primarily to satisfy homologation rules, creating machines that were essentially competition cars with license plates.