The Other Mille Miglia Coupe

In 1938, BMW built a radical competition coupe that put the latest aerodynamic principles into action and showed off the capabilities of a strong new design department.

The Other Mille Miglia Coupe 1
July 13, 2010

Among BMW fans, it’s no secret that the pre-war 328 put the white and blue roundel on the world stage. In its debut at the Nürburgring on June 14, 1936, the prototype 328 driven by Ernst Henne swept aside all opposition in the two-liter sports car class and established a precedent for dominant performance that wouldn’t end until World War II put an end to racing on the Continent. With a light tubular frame and an in-line six producing 80 bhp at 5,000 rpm—early cars had at least 90—the 328 sealed BMW’s reputation for speed with style.

Complementing the 328’s technology was clean-lined bodywork that was modern without being bizarre. Like the rest of the 328, it was the work of a technical department that was expanding rapidly and professionally.

Though previously based in Munich, BMW’s vehicle development group moved in 1934 from Munich to Eisenach, where car production took place. Its 20 employees would work under Fritz Fiedler, BMW’s chief engineer.

Reporting to Fiedler in charge of body engineering was Peter Szymanowski, who assigned Wilhelm Kaiser to draw up design plans for the 328. Starting from 1936’s hand-made prototypes, the aim was to design a body that used stylistic elements of the 326 and could be assembled with relatively modest resources from available panels.

Soon, however, it became evident that the body design operation was too underpowered to meet its many objectives. In 1937, BMW’s car development department moved back to Munich, where a new artistic design department was created. It opened its doors on September 1, 1938, and its chief was stylist Wilhelm Meyerhuber, recruited from General Motors-owned Opel.

Slender and sharp-featured, Meyerhuber learned his craft in the 1920s at General Motors and its Fisher Body Company, firms that pioneered the modern styling department. Wilhelm Kaiser moved over from engineering to join Meyerhuber, who also brought in Opel stylist Karl Schmuck. These three designers formed the core of the team that worked until wartime on the styling of all BMWs, including those planned for post-war manufacture. On the engineering of the bodies, they liaised with Szymanowski.

New concepts in aerodynamics

The establishment of BMW’s styling studio coincided with a period of accelerated change in body design. Separate trunks, spare wheels, fenders and running boards were being subsumed into the main body shape, while radiators were disappearing behind grilles. In the latter movement, BMW had a brilliant head start with its twin kidneys, though the Munich stylists would otherwise find it a constant challenge to keep pace with rapid change.

The transformation was especially rapid in the shaping of sports racing cars. By 1937, the most advanced sports racers had all-enveloping bodywork, with smooth flanks that kept aerodynamic drag at a minimum. Two landmark designs launched this trend in 1936. The first was from Bugatti, whose open-cockpit 57G “Tank” was a major advance. It scored its first wins in 1936, won Le Mans in 1937 and again—in a new version—in 1939.

The second were made closer to home: the exotic streamlined sports racing coupes designed for Adler by aerodynamicist Reinhard von Koenig-Fachsenfeld. Von Koenig drew on the aerodynamic concepts of Paul Jaray to create the ultra-low-drag Trumpfs, not only for sale but also to compete in international sports car races. In 1936, helped by their radical long-tailed shapes, the Adlers took the top three places in their class at the Spa 24-hour race.

A further stimulus to low-drag body development came in June 1937. In a surprise announcement, Germany’s Nazi government revealed that a competition was planned for the following year that would put all previous long-distance events in the shade: a race from Berlin to Rome, linking the two Axis allies. In contrast to the tortuous Mille Miglia, this would be a high-speed race, making as much use as possible of the German autobahnen and the fastest Italian autostrade.

BMW engine genius Rudolf Schleicher took careful note of this revelation. He was well aware that the 328’s 2.0-liter six, though clever, was limited in its potential. Its elaborate pushrod valve gear and its long, 96mm stroke imposed strict limits to its range of revolutions. Also, competition in the 2.0-liter class could be expected from Mercedes-Benz, Adler and Wanderer, not to mention Alfa Romeo and Lancia. Something special would be needed to keep BMW competitive.

The Other Mille Miglia Coupe 2

That “something” would be low aerodynamic drag. Having set world records with streamlined and faired motorcycles, BMW was well aware of the potential of low-drag bodywork. Since only open cars were admitted to sports car races in Germany, new forms would be researched for the 328 roadster, while the closed coupes that would be allowed in the Berlin-Rome race would be explored, as well. Although coupes increased the cross-sectional area that had to be forced through the air, they could negate that disadvantage by reducing the friction drag caused by the car’s shape.

Schleicher made contact with Reinhard von Koenig-Fachsenfeld to have designs prepared for aerodynamic bodywork based on the Jaray patents, as had already been shown to work on the Adlers. Scale model tests showed lower drag, but at the price of marked instability. Moreover, Schleicher thought the Jaray-style bodywork left a lot to be desired from an aesthetic point of view.

Nevertheless, a number of BMW 326 and 328 chassis were bodied for private owners to Adler-like shapes by Wendler of Reutlingen using von Koenig-Fachsenfeld’s Jaray-influenced designs. Such bodies raised the 328’s maximum speed from 93 mph to just over 110 mph following a change in the rear axle ratio, as well.

Kamm’s experiments pay off

Back at Eisenach, Schleicher gave Rudolf Flemming and Alfred Kempter the job of designing a low-drag body based on the revolutionary concepts of Wunibald Kamm. Kamm headed Stuttgart’s Motor Vehicle Research Institute, known by its German acronym FKFS, which he had founded in 1930 at the age of 37. His contacts with BMW dated from 1925, when the Munich company considered manufacturing a front-drive car that the precocious Kamm had created in prototype form.

Kamm’s facility at Stuttgart’s Technical High School had two wind tunnels, both designed for automotive work. A small round-section tunnel served for scale model tests, while a vast D-section tunnel was built for full-scale investigation. BMW was planning a tunnel of its own, but it wasn’t yet ready.

Starting in 1935, the FKFS began refining a radical theory that Kamm’s team had discovered in the wind tunnel. While Paul Jaray’s cars had long pointed tails, Kamm used an almost-square tail. As his research had shown, in both theory and practice it was possible to make a low-drag vehicle shape whose surfaces followed the best possible flow lines as far rearward as was practical—and were abruptly cut off.

When news of this discovery was published, in 1936, the Jaray-minded Germans thought it was an April Fool’s joke! That’s not surprising: For decades afterward, many were reluctant to grasp that a flat-backed shape could give as low or lower drag than the optically more appealing pointed tail. That Wunibald Kamm placed his personal reputation behind the new idea, however, eventually led to its being dubbed the “K-form,” and the FKFS built several four-door sedans on BMW chassis to verify this radical principle in full scale.

In response to Schleicher’s request, the FKFS carried out a wide-ranging study of shapes for both sedans and sports cars. Existing BMWs were modeled in one-tenth size and then modified to observe the consequences, while new experimental shapes were tested, as well. The model tests showed a drag coefficient of 0.59 for the 315 roadster, reduced to 0.51 by the smoother lines of the 328. (The lower the coefficient, the less the drag, a flat plate being equal to 1.00.) A final test series explored 18 different sports car configurations.

The tests conclusively proved the aerodynamic advantage of a closed body over open alternatives. While the best roadster designs promised a drag coefficient of 0.28, a comparable coupe could attain a more slippery 0.22, a reduction in resistance that more than made up for its added frontal area. BMW would commission advanced envelope-bodied roadsters for racing, and it would also initiate the building of an experimental coupe.

In October of 1938, just after the opening of Meyerhuber’s styling studio, Rudolf Flemming’s first 328 coupe was ready to drive. Created as project AM1007, both its aluminum bodywork and its rudimentary steel-tube structure were fabricated at Eisenach. Its design was an elaborate interpretation of the successful wind tunnel model.

“However,” wrote a BMW source, “the car was far from convincing. The Eisenach-built body fell short of the mark in terms of workmanship, and the car’s handling left a great deal to be desired. While the car achieved previously undreamed-of speeds on test runs, it was so unstable that it needed the full width of the motorway to do so.”

The Other Mille Miglia Coupe 3

Body engineering chief Szymanowski was contemptuous of its construction, saying that its doors “were far too low, you can’t even get in properly!”

Meyerhuber adapts the principle

This was Meyerhuber’s chance to gain traction in his new post as head of BMW styling. Munich took over from Eisenach to design and build a new version of the coupe, designated AM1008. Just four weeks after he joined BMW, Meyerhuber was ready to present not only the first drafts for a 328 successor but also his scheme for a new version of the Berlin-Rome racing “sedan,” as this car was known at BMW. Professor Kamm was asked for his views on measures to make the closed car less wayward at speed.

The Meyerhuber version had a less bulbous tail and improved driver and passenger access. To improve stability, its wheelbase was extended by 20cm, almost eight inches. All aspects of the design were refined, especially at the front, where the “kidneys” were interpreted as two narrow verticals with horizontal grillework. Wilhelm Kaiser took charge of the body engineering, which included a new magnesium alloy structure for the aluminum bodywork.

Munich workshop foreman H. Heuss oversaw the creation of AM1008, a “racing sedan” that was as stylish as it was speedy. With other development programs clogging his facilities, however, it took several months to put the car together. Seeing the potential of the closed 328, leading racer Prince Max zu Schaumburg-Lippe asked BMW to build him one, as well. The company responded that it was having enough trouble finishing its own car without making another.

Not to be denied, Schaumburg-Lippe turned to Milan’s Carrozzeria Touring to produce a streamlined body on the 328 chassis. Following the lines of a similar car they’d bodied for Alfa Romeo, the Italian craftsmen came up with the finished article in just four weeks. Capable of 125 mph with adequate stability, the Touring 328 coupe made its debut in 1939’s Le Mans 24-hour race, where Schaumburg-Lippe and BMW engineer Hans Wencher drove it to fifth place overall and first in the 2.0-liter class.

The Italian body was a yardstick for the efforts of Meyerhuber’s team. The German body was more voluminous, but AM1008 weighed just 1,675 lbs. versus the Touring-built car’s 1,720 lbs.—a successful result. In late summer 1939, BMW racing chief Ernst Loof gave the car a thorough wringing-out on the Munich to Salzburg autobahn, allowing further improvement to a host of details.

The investment of time and effort paid dividends. AM1008 had better directional stability than its predecessor, proving far less sensitive to side winds though still not immune to their effects. While the Touring coupe’s drag coefficient was on the order of 0.35, that of the Meyerhuber creation was nearer 0.25. Proving capable of a record top speed for a BMW of 140 mph, the handsome coupe was the odds-on favorite to win its class in the Berlin-Rome contest.

The epic race from Germany to Italy through Austria was postponed several times, finally being scheduled for September of 1939. At the beginning of that month, however, Adolf Hitler’s drive into Poland left this plan in ruins—along with so much else. Nevertheless, both Germany and Italy left several auto races on the calendar for early 1940. The German events were soon cancelled, but those in Italy included the Tripoli Grand Prix (Libya was still an Italian colony) and the Mille Miglia.

Set for April 28, 1940, the Mille Miglia was to be run over a 104-mile triangular course linking Brescia with Cremona and Mantua. The drivers would complete nine laps of the new circuit, which followed well-surfaced roads through flat countryside. The race included long straight sections that were expected to lead to high average speeds—made to order for the Meyerhuber sedan.

BMW signed up two experienced Italian drivers—Count Giovanni Lurani Cernuschi and Franco Cortese—to pilot the works AM1008 sedan. While the Munich team dared to think of overall victory, tradition suggested that Alfa Romeo was far more likely to win outright. BMW’s Italian driver pairing was certainly in with a chance, though, and the Meyerhuber design had displayed superior handling in testing while attaining much higher speeds than its Touring-bodied sister.

The advantage didn’t pay off in the race. The Italian-bodied 328 driven by Baron Huschke von Hanstein and Walter Baumer led the race outright, completing each lap in less than an hour. This wasn’t matched by the “sedan,” though it held second place overall through the second lap. On lap seven, unfortunately, its engine lubrication failed due to sheer lack of oil, and a post-race teardown revealed that wrongly installed piston rings had pumped out nearly all the lubricant. Trying to avoid total failure, Count Lurani had slowed his pace to try to finish.

The Other Mille Miglia Coupe 4

A post-war daily driver, and a latter-day recreation

Repatriated to Munich, the unique 328 was restored to rude health. During the war, the BMW experimental department under Rudolf Schleicher was dispersed for its protection to buildings in the garden of Eisholz Castle at Berg in the hills ringing the Starnberg Lake south of Munich. There, some 90 staff members had a complete car fleet at their disposal, including the Meyerhuber 328. Wearing registration IAA-27129, it was carefully camouflaged and hidden behind an outbuilding, where it survived its “sleeping beauty” years in good shape.

When the war was over, the racing sedan came into the hands of someone who fully appreciated it: former BMW racing chief Ernst Loof. Searching his devastated homeland for any and all 328 parts, Loof was readying the ground for his new Veritas cars, which would be based on BMW designs. The Meyerhuber machine became his daily driver.

By 1947, AM1008 was sidelined as Loof completed his first Veritas racers. It was called back to front-line service, however, when Karl Kling’s new Veritas wasn’t ready for the big race at Hockenheim in May.

“My friend Ernst Loof came to my rescue,” said Kling, explaining that Loof dusted off the eight-year-old coupe that “represented all Ernst Loof’s worldly possessions and in the days of the Reichsmark was worth a very good figure indeed.

“Having been laid up during the war,” Kling continued, “the car was by no means in its best condition, but this was a relatively minor point and certainly did not diminish my enthusiasm. At Hockenheim, I climbed into her with high hopes and great expectations. With quick acceleration, the car shot away. I must confess, however, that she ran rather roughly. The shock absorbers were worn out, and owing to the centrifugal force the oil stayed in the left of the sump, with the result that the engine stalled badly on both left bends.

“In spite of these drawbacks,” Kling related, “I drove the fastest time of the day and won the two-liter sports-car class with an average speed of 95.01 mph. I hung my victory wreath of laurels on the man who most deserved it—Ernst Loof.”

So gentle were the bends on the fast Hockenheim oval that the BMW could race with the spats over its front wheels that had been tested in 1939 but not used in the Mille Miglia, where more steering lock was needed.

In 1950, Loof decided to unlock the value represented by his unique BMW coupe and sold it to a building contractor in Bad Godesberg. A 1952 photo, taken on the grounds of the Veritas works, shows it freshly painted with all four wheels enclosed and bumpers and direction signals fitted, replacing the original swing-out trafficators. Not long afterward, however, it was heavily damaged in a crash and scrapped.

Although BMW owns the Touring-bodied 328 Coupe that won the Mille Miglia, as well as a replica of that car, it has long had an itch to possess this pioneering coupe as well, as an example of the company’s own design work at a crucial stage of the company’s evolution. Since the mid-1990s, BMW Group Classic has been scheming to bring Wilhelm Meyerhuber’s masterpiece to life, and in April 2010 the recreated AM1008 was unveiled at Concorso d’Eleganza Villa d’Este. Impressively, it also took part in this year’s Mille Miglia Storica.

Though BMW refers to this 328 as the “Kamm Coupe,” I prefer its association with Wilhelm Meyerhuber. While the car was indeed shaped according to Kamm’s principles, its actual design is purely attributable to Meyerhuber, who in the years just before the war was creating new designs for sports cars and sedans that not only set a new direction for BMW but also inspired many advanced designs after the war, to mention only Bristol, Frazer Nash, Jaguar and the inimitable MGA.

Great to see you again, AM1008, and to be reminded of Meyerhuber’s fine work.

Also from Issue 93

  • E92 M3 GT4 imported to U.S.
  • 2011 F25 X3 preview
  • Interview: R. Steinberg on electrics
  • Buyer’s Guide: Best first BMWs
  • Active Autowerke E92 M3
  • Phil Ganderton’s R53 MINI
  • Kivanc Aslaner’s E30 318is
  • Eddie Ribeiro’s E12 528i
  • Paul Cain’s 2002 vs. E82 135i
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