THE ROTOR ROUTE

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By Sivan Goren and images from Etienne Fouche

Regular readers would remember our story about the first sportscar to use the German Wankel-designed rotary engine – the Japanese Mazda Cosmo. But there was another car, far closer to home for Herr Wankel, that was not only the first mass-production saloon to use this engine but also won Car of the Year soon after it was launched. Think that’s incredible? Well it’s not nearly as astonishing as the fact that the revolutionary NSU Ro80 was the cause of its manufacturer’s eventual demise.

NSU actually began in 1873 as – of all things – a manufacturer of sewing and knitting machines, NSU being an acronym for Neckarsulm Strickmachinen Union (Neckarsulm Sewing Machine Co). Twenty years later the stitching machines had been replaced with bicycles and by 1901, the operation began building motorcycles. In 1905, NSU began to produce motor cars, followed shortly thereafter by trucks.

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Sadly, though, NSU’s timing was not ideal. Although the company produced some successful cars in the 1920s, the onset of The Great Depression forced NSU to sell the automotive side of its business to Fiat in 1932, and the start of WWII meant it had to focus exclusively on motorbike production in order to survive. By 1955, NSU had become the biggest motorcycle producer in the world.

But the magic of four wheels could not be resisted for long: in the mid-1950s NSU once again tried its hand at motor cars, introducing the NSU Prinz in 1957. While NSU had offered 4- and 6-cylinder cars back in the 1920s, the Prinz was a rear-engined mini car powered by an air-cooled, 2-cylinder engine. Although well made (if somewhat noisy), the Prinz did not even put a dent in the VW Beetle’s total market domination of the time.

Over the next few years, the post-war German economy continued to improve and buyers were gradually moving away from two wheels and mini cars to larger and more luxurious saloons. Although NSU introduced its first 4-cylinder post-war car, the Prinz 1000, at the 1964 Frankfurt auto show, NSU managing director Gerd Stieler von Heydekampf realised that with NSU’s market share being already only modest, it was time to evolve – or the future would be bleak.

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In late 1962, NSU began developing a new model known internally as ‘Typ 80’ which was to be in the same class as the Ford Taunus P4. The Typ 80 had monocoque construction and front-wheel drive, developed by chief engineer Ewald Praxl, and in-house designer Claus Luthe began design work in early 1963. A full-size model was eventually presented to the NSU board in 1964. Apart from its clean and spacious design, it was extremely aerodynamic – low drag was a significant part of the brief, in order to maximise fuel economy – and with a drag coefficient of 0.355, only the Porsche 911 and Citroën DS21 even came close.

 The eventual production model was very close to the original model in shape, but not in dimensions. When executives realised what it was going to cost to produce, they decided to up their target market in order to compete with cars in the executive market. And in order to do this, the Typ 80 was scaled up in size, weight, and price. But apart from all this, and maybe something I should have mentioned first, was the Typ 80’s most significant feature: its rotary engine. Under the bonnet was a 2-rotor 115hp Wankel engine.

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After considering a variety of possible names, NSU finally settled on the straightforward Ro80, ‘Ro’ for Rotary and ‘80’ for the type number. The Ro80 was an all-new design that shared very little with NSU’s other models and was considerably more sophisticated, featuring power-assisted ZF rack-and-pinion steering and fully independent suspension. Its chassis was superb and the combination of a wide track, low centre of gravity, and fine steering made for excellent handling. Its ATE Dunlop disc brakes all around (mounted inboard at the front) made for a smooth ride, due to its low unsprung weight. Despite the engine’s inherent lightness, power steering was standard.

While the 2-rotor engine used in the Ro80 was considerably more powerful than the Typ 80’s original specification, the car’s weight had also increased by more than 50%, which raised questions about what transmission should be used. NSU finally chose the 3-speed Saxomat, a semi-automatic transmission made by Fitchel & Sachs. There was no clutch pedal; touching the gear lever knob operated an internal electric switch that operated a vacuum system which disengaged the clutch, and the gear lever itself could then be moved through a standard ‘H-pattern’ gate. A two-pedal car which allowed you to choose when to shift gears… a case of the best of both worlds?

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Production began in August 1967 but by then NSU’s back was well and truly against the wall. Although its existing cars were selling reasonably well, the company was no longer in the motorbike business and had invested nearly all of its available resources in the Ro80 and the follow-on Typ 70 (a smaller piston-engined car intended as NSU’s answer to the BMW 1600/1602). Von Heydekampf openly admitted to the press that NSU had everything riding on the Ro80 and the company simply couldn’t afford to wait any longer for launch. The Ro80 made its public debut at the Frankfurt show in September 1967 and it went on sale shortly afterward with a hefty price tag – substantially more than a Mercedes 230.

The price was high but there were far greater problems ahead for NSU. The rotary engine proved to be highly problematic. It was not only very thirsty but also had a voracious appetite for oil and spark plugs (specific plugs which were at least 10 times more expensive than standard ones), which made the car costly to maintain. Despite all this, and possibly because the world had never seen such an original and novel car since the Citroën DS, the new model won the European Car of the Year. And despite its high price, initial 1967-68 sales totalled around 6 400 units.

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But soon an inherent design flaw began to rear its ugly head. The designers of the car had misunderstood their target market in one fatal way: they had assumed that the car would be used on the open road and on autobahns. But instead, these cars were bought for wives who drove them only to the shop and back. Stop-and-go driving not only fouled the plugs, but also wreaked havoc with the engine’s 3-piece, self-adjusting apex seals, particularly with frequent use of the manual choke. To add to NSU’s monumental headache, drivers of this car also seemed to have a penchant for dangerously over-revving the engine because it was so smooth that it would exceed its redline without much complaint. (As an aside, cars produced after 1971 came with an ‘acoustical signal’ that warned the driver when the engine was rotating too fast.)

You can guess what happened next, right? Engine failures – and lots of them – many at less than 40 000km. In a misguided attempt to do right by their buyers, NSU generally opted to replace the engines rather than repair or rebuild them – and sometimes more than once – even beyond the 32 000km factory warranty. This, understandably, wound up costing the company hugely not only financially but also because, despite being a noble attempt to placate irate customers, it actually did more damage to the company’s reputation.

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By early 1969 it was clear that NSU had to do something drastic. At the same time, Volkswagen’s new MD, Kurt Lotz, was looking for the way forward to fill the gaping hole left by the stellar Beetle and wanted to expand Volkswagen’s product range and production capacity. NSU badly needed a cash injection but von Heydekampf was extremely reluctant to sacrifice its independence. The two operations entered into talks and eventually a compromise was reached: NSU would merge with the manufacturer that Volkswagen had a controlling interest in – Auto Union. The merger, announced in March 1969, resulted in a new company called Audi-NSU-Auto Union – essentially the beginning of today’s Audi.

Following the merger, NSU continued developing the Wankel engine and working to fix the Ro80’s issues. The changes made the Ro80 much more reliable but already the car had developed an unfortunate reputation and had become a bit of a laughing stock in the German media, with editorial cartoons in magazines cruelly depicting NSU drivers greeting each other with hand signals to indicate how many engines their car had gone through. In addition, sales for 1970 were down and in 1971 sales fell a further 50%. Although things improved somewhat in 1972 and 1973, the fuel crisis hit the Ro80 hard. Production dropped sharply in ’74 and ’75, helped along by the car’s constant price escalation.

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At this point it seemed the only way the Ro80 would survive is if it could evolve. There had been rumours of a second-generation Ro80 in the press for several years, with plans for a larger, more powerful 1500cc engine aimed at 6-cylinder piston-engined rivals. But the truth was that while there was some support within the company, technical director Ferdinand Piëch was increasingly sceptical about the rotary engine’s viability in the European market. He believed that diesel was a better way forward than the rotary, which still suffered from relatively poor thermal efficiency and heavy fuel consumption. Piëch eventually succeeded in ending Wankel development and the Ro80 successor project was canned.

And so the NSU Ro80 finally spluttered to a stop in April 1977. It was the last NSU production car, although NSU remained part of the corporate name until the mid-1980s and the marque is still owned by Volkswagen AG. Exact production figures differ depending on who you ask, but most sources agree it was around 37 400 units. Although the Ro80 could be considered a huge failure for NSU, it made quite an impression in its short life. In the end it was a huge risk that just did not pay off – maybe if timing had been different or the planets had been aligned the story might have turned out differently? Either way, it sure did make for one hell of an interesting car – not to mention the start of a certain four-ringed powerhouse manufacturer…

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