History of the Opel Manta B400

 Opel Manta 400 – A Car Lost in History 

The Opel Manta was a car that the wallets of young drivers could support unlike the cars they dreamt of such as the BMW sedans or the Italian roadsters. The Opel Manta was similar to the Ford Capri as both cars used many common of the shelf parts. There were two versions of the Opel Manta, a Manta A that was launched in the year 1970 ahead of the new Opel Ascona the four-door version of the Manta and the Manta B 400. This write up is going to focus on the Manta B 400, the second generation that was released in 1975. The reason I am not focusing on the Manta A is because it looked outdated from the time it was released and doesn’t call for a detailed analysis. The Manta B was no looker either however, the no-nonsense square body allowed the driver to get a grate visibility. 

The regular Opel Manta

The regular Manta B was still a mundane two door three-box hatchback, that had a 1.9L engine with a cam in head preventing it from revving freely and produced a miserly 90Hp. The only selling point for the car was the live rear axle, it was offered with coil springs (unlike its competitor, the Ford Capri which had leaf springs), and the front had double wishbone suspension. Contemporary car reviews stated that the car possessed excellent stability and chassis balance. The steering also offered rewarding feedback with precision. The car was never unsettled by mid corner bumps. Due to this it could be driven flat out through corners and on mountain roads. All these features made the car a good base to build a rally car. This unnerved GM which lead them to shift from group 4 racing to group B rally. 

The Manta 400 

The debut of this car is something that is not attainable in today’s car market, a German subsidiary of an American car manufacturer collaborating with an independent tuning company to create a homologated car for rallying. From the early 1980’s a company called Irmscher had proven to be a genuine talent when it came to tuning cars with a motto that tuning is not to be equated to tinkering. This allowed their cars to be sold through Opel dealers. 

Who was Irmscher?   

Günther Irmscher

Irmscher is a firm founded by Günther Irmscher (senior) in 1968 in a double garage in the town of Winnende near Stuttgart. Günther Irmscher was a rally driver and mechanic having tuned and raced his own car and later developing his own cars that took part in national and international rallying and circuit racing championships. They developed a reputation for their innovative tuning tech and reliable technical execution. 

Irmscher i2800

Before we read about the B400A, I want to briefly highlight a special car built by Irmscher, prior to Opel officially entering the Group B rally. The car was the Manta B i2800. There were a total of 27 i2800 ever built and only 15 remain. It had a 2.8L engine from a Commodore B and a 5 speed Getrag transmission. The car also had Irmscher spoilers all around and it sat on Bilstein sports shock absorbers and 7×13 ATS rims painted white.

Irmscher i2800

The development of the B400

The Ascona B400

Having now read about Irmscher, an independent tunning company that still stands to this date providing parts for modern Opel’s and Fiat’s, it is easy to understand why Opel chose them to help develop the body kit for the Manta B400. Once the Group B rally regulations were clear Opel chose to develop a car to enter this category of rallying. The original plan was to develop and use a 2L 4-cylinder engine. For this purpose, Cosworth developed a set of new 16V cross flow heads. This, however, did not produce the desired power output. Following which, the engineers developed a new crank shaft and engine block leading to a higher output of 2.4L. This resulted in a power output of 144hp in the road going version. The rally version had a higher output of 250hp this was because the rally version used carburettors instead of fuel injection. The basic version of the B400 looked mundane and stood no competitive chance with its 144hp and tiny 15inch alloys. There was an optional kit for regular buyers from Irmscher that provided wider wheels, wheel arches, splitters, a three-piece rear wing and more power. The phase 2 of this package offered a power increase to 280hp. 

The 2.4L engine 

The car rode stiff which was attributed to the double wishbone suspension in the front and Panhard rods for the four-link live axel in the rear. The car also came with a ZF limited slip differential and the Getrag 5 speed gearbox. The car weighed just 1168kgs with a stated power output of 144hp and a torque output of 250nm which saw this car going up to a top speed of 130mph.   

On the inside

The interiors were hardly the focus of this car, fitted with cheap plastics it was mainly built to last rather than feel plush. The seats were provided by Recaro and had the Opel logo repeatedly running down the middle, they were narrow and designed to hold one in place. The steering wheel was an Opel sports steering wheel with raised nodules on the back to provide better grip. 

Why the name B400

The former car the Ascona B 400 was used to race in the group 4 of the Fédération Internationale du Sport Automobile (FISA) racing. It was mandatory to have 400 road going cars for homologation purpose. When Opel entered the group B rally competition, they were required to manufacture only 200 units for homologation, but they chose to retain the 400 in the name. The Manta B400 never saw a rally stage in the group B category in the year of 1981, as a difficulty in the production line at Antwerp Belgium saw only 23 cars making it out of the factory. The required number of cars were only met by September of 1982, leading them to enter in the year of 1983 by which time it was decided that Audi were clear winners, with their Audi quattro’s all-wheel drive system. The Manta with its mechanical layout was no match. Opel did have an AWD Manta prototype built in Coventry with Ferguson, but poor handling and costs for homologation never saw it becoming a reality. 

The AWD Prototype

The AWD Layout

By the year 1984 a total of 245 units were rolled out, and 25 of those cars were seen being entered in various European rally stages and circuit races by the factory team. The biggest achievement for the B400 was winning the rear-wheel drive class in the Paris-Dakar Rally in 1984 along with fourth over all place.  Erwin Weber and Gunther Wanger won the German rally championship in 1983. The car also captivated the audience in the mid 1980’s in the British rally championship, driven by Jimmy McRae and Russell Brooks. The famous Manta with the AC Delco Manta was sideways and spectacular coming out of every corner with its flickable and nimble chassis supported by the rear-wheel-drive layout. The layout made it spectacular to watch, as it locked its wheels entering the turn in a cloud of smoke and later exiting the turn hitting the rev limiter. Tight turns for this longer chassis were not a problem at all. 

Jimmy McRae's car

This was a small history about the Opel Manta B400 one of the last few cars that was manufactured by a subsidiary of a larger American car manufacturer, this is something that would no longer be possible. The very thought of creating a factory car for rallying with an independent tuning company would set of alarms and never be executed. Hence this car stands as one of its kind and a car that was lost in history due to the fame of the Group B rally championships and the cars that took part in that series.