The Auto Union Grand Prix racing cars types A to D, were developed and built by a specialist racing department of Horch works in Zwickau between 1933 and 1939.
Between 1935 and 1937 Auto Union cars won 25 races, driven by Ernst von Delius, Tazio Nuvolari, Bernd Rosemeyer, Hans Stuck and Achille Varzi. Much has been written about the difficult handling characteristics of this car, but its tremendous power and acceleration were undeniable - a driver could induce wheelspin at over 100 mph (160 km/h).
The cars throughout their production history were the main Grand Prix protagonists with Mercedes-Benz, particularly dominant in 1936. The dominance of the Silver Arrows of both brands was only stopped by the outbreak of World War II in 1939.
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Having been made redundant from Steyr Automobile, Dr. Ferdinand Porsche founded Porsche in Stuttgart, with engineering colleagues including Karl Rabe, and financial backing from Adolf Rosenberger. Unfortunately, car commissions were low in the depressed economic climate, so Porsche founded a subsidiary company Hochleistungs Motor GmbH (High Efficiency Engines Ltd.) in 1932 to develop a racing car, for which he had no customer.[1]
In 1933, Grand Prix racing was dominated by French and Italian marques Bugatti, Alfa Romeo and Maserati. In early 1933, governing body AIACR announced a new formula, with the main regulation meant that the weight of the car without driver, fuel, oil, water and tyre was not allowed to exceed 750 kg (1,700 lb). This was created to restrict the size of engine that could be used, with the authority estimating that this weight limit would allow around 2.5 litre engines.[2]
Based on Max Wagner's mid-engined 1923 Benz Tropfenwagen, or "Teardrop" aerodynamic design, also built in part by Rumpler engineers,[3] the experimental P-Wagen project racing car (P stood for Porsche) was designed according to the regulations of the 750 kg formula. On November 15 chief engineer Rabe submitted the first draft to the planning office of a racing car for the new formula, with Josef Kales responsible for the V16 engine, while Rabe also held responsibility for the chassis.[1]
In 1932 Auto Union Gmbh was formed, comprising struggling auto manufacturers Audi, DKW, Horch and Wanderer. The Chairman of the Board of Directors, Baron Klaus von Oertzen wanted a show piece project, so at fellow director's Adolf Rosenberger insistence, von Oertzen met with Porsche, who had done work for him before.[1]
At the 1933 Berlin Motor Show, German Chancellor Adolf Hitler announced two new programs:[1]
German racing driver Hans Stuck had met Hitler before he became Chancellor, and not being able to gain a seat at Mercedes, accepted the invitation of Rosenberger to join him, von Oertzen, and Porsche in approaching the Chancellor. In a meeting in the Reich Chancellory, Hitler agreed with Porsche that for the glory of Germany, it would be better for two companies to develop the project, resulting in Hitler agreeing to pay ₤40,000 for the country's best racing car of 1934, as well as an annual stipend of 250,000 Reichsmarks[1] (₤20,000)[4] each for Mercedes and Auto Union. (In time, this would climb to ₤250,000.)[5] This highly annoyed Mercedes, who had already developed their Mercedes-Benz W25, which nevertheless was gratified, its racing program having financial difficulties since 1931.[5] It resulted in a heated exchange both on and off the racing track between the two companies for until World War Two.
Having garnered state funds, Auto Union bought Hochleistungs Motor GmbH and hence the P-Wagen Project for 75,000 Reichsmarks, relocating the company to Chemnitz.[1]
The layout of the car was unusual for the time, being mid-engined, years before the Cooper T53 rediscovered the advantages. Hence, the layout of the car front to rear was: radiator; driver; fuel tank; engine.
The problem with mid-engined design at the time was the stiffness of the contemporary ladder chassis and suspension, which resulted in a pronounced change in turning angle as the momentum of the centrally mounted engined changed on the chassis, and resulted in the car oversteering. The suspension was all-independent, using parallel trailing arms and torsion bars at the front, while at the rear Porsche tried to counter the natural oversteer tendency with the use of a then advanced swing half-axle rear suspension. It was only on the later Type D that the rear suspension would be replaced with a de Dion system, following the lead of Mercedes-Benz, but by then it was too late to do anything about the poor handling reputation the cars had gained.
The cars used supercharged engines that eventually produced almost 550 horsepower (which also contributed toward the handling difficulties, as it promoted oversteer which the cars already had in abundance). The engine was originally the V16 engine that Porsche had started designing earlier; when, starting in 1938, the maximum engine displacement for Grand Prix cars was limited to 3 litres for blown engines, it became a V12. It was originally designed to 6 litre specifications, but would start at 4,360 cc and 295 bhp (220 kW). It had two cylinder blocks, inclined at an angle of 45 degrees, with a single overhead camshaft to operate all 32 valves. The cylinder heads were hemispherical, with the intake valves on the inside, directly connected to the camshaft through rocker arms. The rocker arms of the exhaust valves were connected to the camshaft by pushrods that passed through tubes situated above the spark plugs; thus the engine had three valve covers. The engine was designed to provide optimum torque at low engine speeds, with Bernd Rosemeyer later driving a car around the Nürburgring in a single gear, to prove the engine was flexible enough to do it.
The body was subjected to strenuous testing in the wind tunnel of the German Institute for Aerodynamics, a scientific organization that still exists. The fuel tank was located in the centre of the car, directly behind the driver, so that the car's front-rear weight distribution would remain unchanged as the fuel was used: exactly the same location used in modern open-wheel racing cars, and for the same reason. The chassis tubes were initially used as water carriers from the radiator to the engine, but this was eventually abandoned after they often sprung small leaks.
The development of Auto Union racing cars began 1933 by specialists of Horch works. The first cars ran in the winter 1933/34, on the Nürburgring, AVUS and Monza. Further development was stopped completely in 1942.
As Mercedes had former racing driver turned designer Rudolf Uhlenhaut, who could provide excellent feedback on the car and required developments; Auto Union were forced to create in-car measuring systems to provide additional feedback. Auto Union used clockwork mechanism and a paper disc to record data such as engine revs while the car was being tested, allowing the engineers to study the collected data at a later date.[2] It was found that additional work was needed on the car's cornering behaviour, as when accelerating out of a corner would cause the inside rear wheel to spin furiously. This was much abated by the use of a Porsche innovation, a ZF manufactured limited slip differential, introduced at the end of the 1935 season.
After the development of the Type A, Ferdinand Porsche became focused on development of the factory facilities for production of the Volkswagen Beetle at Wolfsburg, handing over his daily role to his son Ferry. The co-operation between Porsche and Auto Union continued through Types A, B and C until the 750 kg formula ended in 1937, as engineering developments had resulted in huge engines in lightweight vehicles creating great horsepower, and hence high speeds and excessive accidents. Dr. Ing. Robert Eberan von Eberhorst was responsible for the new Type D car, which while still retaining the 750 kg weight limit, also restricted capacity to 3Litre with a compressor, or 4.5Litres without. The Type D deployed a 12 cylinder engine, while the hill climbing versions of the Type D where the capacity limit was not enforced used a changed gearbox and final drive to retain the 16-cylinder engine of the Type C.
This section only includes results of second or better.
The list of drivers for the initial 1934 season was headed by Hans Stuck; he won the German, Swiss and Czechoslovakian Grand Prix races (as well as finishing second in the Italian and Eifel Grands Prix), along with wins in a number of hill-climb races, becoming European Mountain Champion. (There was no European Championship for the circuit races that year, or he would have won that too). August Momberger placed second in the Swiss Grand Prix.
In 1935, the engine had been enlarged to five litres displacement, producing 370 bhp (280 kW). Achille Varzi joined the team and won the Tunis Grand Prix and the Coppa Acerbo (along with placing second in the Tripoli Grand Prix). Stuck won the Italian Grand Prix (along with second at the German Grand Prix), plus his usual collection of hill-climb wins, again taking the European Mountain Championship. The new sensation, Bernd Rosemeyer, won the Czech Grand Prix (and managed a second at the Eifel Grand Prix and Coppa Acerbo).
Hans Stuck also managed to break speed records, reaching 199 mph (320 km/h) on an Italian autostrada in a streamlined car with enclosed cockpit.[6] Lessons learned from this streamlining were later applied to the T80 land speed record car.
For 1936, the engine had grown to the full 6 litres, and was now producing 520 bhp (390 kW); in the hands of Rosemeyer and his team-mates, the Auto Union Type C dominated the racing world. Rosemeyer won the Eifelrennen, German, Swiss and Italian Grands Prix and the Coppa Acerbo (as well as second in the Hungarian Grand Prix). He was crowned European Champion (Auto Union's only win of the driver's championship), and for good measure also took the European Mountain Championship. Varzi won the Tripoli Grand Prix (and took second at the Monaco, Milan and Swiss Grands Prix). Stuck placed second in the Tripoli and German Grands Prix, and Ernst von Delius took second in the Coppa Acerbo.
In 1937, the car was basically unchanged and did surprisingly well against the new Mercedes-Benz W125, winning 5 races to the 7 of Mercedes-Benz. Rosemeyer took the Eifel and Donington Grands Prix, the Coppa Acerbo, and the Vanderbilt Cup (and well as second in the Tripoli Grand Prix). Rudolf Hasse won the Belgian Grand Prix (Stuck placed second). von Delius managed second in the Avus Grand Prix.
In addition to the new 3-litre formula, 1938 brought other challenges, principally the death of Rosemeyer early in the year, in an attempt on the land speed record. The famed Tazio Nuvolari joined the team, and won the Italian and Donington Grands Prix, in what was otherwise a thin year for the team, other than yet another European Mountain Championship for Stuck.
In 1939, as war clouds gathered over Europe, Nuvolari won the Yugoslavia Grand Prix in Belgrade (with a second place in the Eifel). Hermann P. Müller won the 1939 French Grand Prix (and took second in the German Grand Prix). Hasse managed a second place in the 1939 Belgian Grand Prix, and Georg Meier a second in the French.
Very rarely were racing cars of the period kept, as components of early cars if required were scavenged for later models and repairs. Secondly, what did remain was often scrapped to provide funds for additional development.
During the latter part of World War II, an estimated eighteen Auto Union team cars were hidden in a colliery outside Zwickau, Saxony, where the Auto Union race shop was based. In 1945 the invading Russian Army discovered the cars, and they were retained as war possessions. As Zwickau post-war was located in Soviet controlled Communist East Germany, what little of the Auto Union racing cars existed were shipped back to the Soviet Union, distributed to scientific institutes and motor manufacturers including NAMI for research.
Today, it is believed that most of the cars were probably reduced to scrap, and that no Type A or Type B cars exist today. Presently it is believed that only one Type C and three Type D cars, and a Type C/D hill climbing car remain.
The sole remaining Type C was originally left to a German museum by Auto Union, after the death of Bernd Rosemeyer resulted in only two or three of these historic cars running. Damaged by bombing during the war, its body today still shows these marks. In 1979/80, Audi commissioned restoration of the car, undertaking a preservation-level overhaul to the body, engine and transmission.
A Type D car was recovered and taken to Moscow to study its technology. In 1976, the car was at the ZIL factory in Moscow and scheduled to be cut up for scrap metal, but Viktors Kulbergs, president of Antique Automobile Club of Latvia, brought it to Riga Motor Museum.
After the collapse of the Soviet Union, a 16cylinder hill climbing car - a combination of types C and D - was discovered in Riga by Audi engineers. In exchange for providing Riga Motor Museum with an exact replica, in 1997 Audi commissioned British engineering companies Crostwaite & Gardiner of Buxted and Roach Manufacturing of Ower to undertake the work. The replica car was unveiled at the 2007 Festival of Speed at Goodwood House, England, with Pink Floyd drummer Nick Mason as driver.[7] The original now resides in the Audi Motor Museum, and tours the major car shows, driven by Hans Stuck Jr., son of the original driver Hans Stuck, a long-time Audi race driver himself; the replica is on display in Riga.[8]
American car enthusiast Paul Karassik tracked down chassis No.19 in Russia, adding an original engine from a separate D-type carcass and handing it over in 1990 to Crosthwaite and Gardiner to restore to its original form. In February 2007, it was due to be auctioned by Christie's in Paris.[9] Although expected to be the most expensive car ever sold at auction at more than $12 million, the car did not find a buyer in the sealed auction. This was because of a discrepancy that was found with the chassis and engine numbers and the fact that they did not correspond with the numbers expected to be found on the car that it was believed to be.[10] The car went on auction in August 2009, with Bonhams estimating a sale price of around £5.5million.[11][12] During Bonhams 2009 Monterey auction, the bidding stalled at $6 million, and the vehicle was not sold.[13]
For 2000, Audi commissioned a Type C Streamline, which in May 2000 raced around the banked curve of the famous French circuit at Montlhéry. This was 63 years after its premier at AVUS in May 1937, when Bernd Rosemeyer took a car of this type to a speed of 380 km/h (236 mph) on the straights.[8] Now resident in the Audi Mobile museum in Ingelstadt, the car has appeared at various autoshows around the world, including the 2008 Goodwood Festival of Speed commemorating Audi's 100th birthday.[8]
In 2004, Audi announced the rebuilt of Auto Union Wanderer Streamline Specials. The three cars were built by European car restorer Werner Zinke GmbH. As part of the celebration, Audi Tradition commissioned a limited edition 1:43 scale model of the car, bearing the start number 17.[14] The rebuilt cars also entered the Liège-Rome-Liège long distance run 65 years after their original Liège-Rome-Liège runs.[15] Two of the cars, owned by Audi Tradition, went on display in its Museum in Ingolstadt, while the third car is owned by Belgian Audi importer D’Ieteren.[16]
In 1947, Automobiltechnisches Büro (ATB) created the Sokol Typ 650 Formula Two racer in the German Democratic Republic, using the talents of chassis designer Otto Seidan and engine designer Walther Träger (both former Auto Union employees), along with spare Auto Union parts and resembled the Type D. As Awtowelo it was successfully tested but never raced.
Audi announced the sale of 999 1:2 scale Auto Union Type C pedal cars. The car was designed at Munich design studio. It features hydraulic dual-disc brake and its speed is controlled by the 7-speed hub gear with back-pedalling brake function. The car was made from aluminium space frame and the aluminium body panels. The seats, framing and steering wheel have been upholstered in leather by a bag-maker, as in the Audi TT, while the spoke wheels were custom-made. The steering wheel can be removed to make getting in and out easier, as in the original. The prototype of the pedal car was unveiled at the Paris Motor Show in autumn 2006.[17]
2008 Audi Type-D concept was designed by Czech Republic designer Lukas Vanek. The engine was rated 650 PS (480 kW; 640 hp). Top speed was estimated 300 km/h (186 mph). It includes LED taillight strip, exposed carbon fibre centre spine, and carbon fibre rear spoiler under the tail.[18]
| Auto Union Racing Cars | ||||
|---|---|---|---|---|
| characteristic | Type A (1934) |
Type B (1935) |
Type C (1936–37) |
Type D (1938) |
| engine orientation | longitudinal | longitudinal | longitudinal | longitudinal |
| engine configuration | V16 | V16 | V16 | V12 |
| cylinder bank angle | 45° | 45° | 45° | 60° |
| engine displacement | 4,358 cubic centimetres (265.9 cu in) | 4,956 cubic centimetres (302.4 cu in) | 6,010 cubic centimetres (366.8 cu in) | 2,990 cubic centimetres (182.5 cu in) |
| bore x stroke | 72.5 mm (2.85 in) x 75.0 mm (2.95 in) | 75.0 mm (2.95 in) x 85.0 mm (3.35 in) | 65.0 mm (2.56 in) x 75.0 mm (2.95 in) | |
| crankshaft | one-piece from Cr-Ni steel | one-piece from Cr-Ni steel | slidingstored (Hirth) | roll-stored |
| valvetrain, ignition system | single camshaft | single camshaft | single camshaft, 2x ignition magnetos | triple camshaft |
| aspiration | 1x Roots supercharger | 1x Roots supercharger | 1 or 2x Roots supercharger | 2x Roots supercharger |
| compressor pressure | 0.61 bars (8.8 psi) | 0.75 bars (10.9 psi) | 0.95 bars (13.8 psi) (max) | 1.67 bars (24.2 psi) |
| motive power | 295 PS (217 kW; 291 hp) @ 4,500 rpm | 375 PS (276 kW; 370 hp) @ 4,800 rpm | 485–520 PS (357–382 kW; 478–513 hp) @ 5,000 rpm | 485 PS (357 kW; 478 hp) @ 7,000 rpm |
| torque | 530 N·m (391 ft·lbf) @ 2,700 rpm | 660 N·m (487 ft·lbf) @ 2,700 rpm | 853 N·m (629 ft·lbf) @ 2,500 rpm | 550 N·m (406 ft·lbf) @ 4,000 rpm |
| transmission gears | 5 | 5 | 5 | 5 |
| maximum speed | 280 km/h (174 mph) | 340 km/h (211 mph) | 340 km/h (211 mph) | |
| brakes | 400 mm (15.7 in), system Porsche hydraulic | 400 mm (15.7 in), system Porsche hydraulic | 400 mm (15.7 in), system Porsche hydraulic | 400 mm (15.7 in), system Porsche hydraulic |
| shock absorber | friction absorber | friction absorber | friction absorber | front: hydraulic rear: hydraulic/friction |
| front suspension | Crank semi-trailing arm (see Volkswagen Beetle) | Crank semi-trailing arm | ||
| rear suspension | Pendelachse with torsion bar suspension (in the back) | De-Dion-axle with torsion bar suspension | ||
| chassis | steel tube leader framework, main pipe diameter: 75 mm (3.0 in) | steel tube leader framework, main pipe diameter: 75 mm (3.0 in) | steel tube leader framework, main pipe diameter: 75 mm (3.0 in) | |
| wheelbase | 2,900 mm (114.2 in) | 2,800 mm (110.2 in) | ||
| axle track width | 1,420 mm (55.9 in) | 1,390 mm (54.7 in) | ||
| dimensions length × width × height |
3,920 mm (154.3 in) × 1,690 mm (66.5 in) × 1,020 mm (40.2 in) | 4,200 mm (165.4 in) × 1,660 mm (65.4 in) × 1,060 mm (41.7 in) | ||
| fuel capacity | 200 L (44.0 imp gal; 52.8 US gal) | |||
| dry weight | 825 kg (1,819 lb) | 825 kg (1,819 lb) | 824 kg (1,817 lb) | 850 kg (1,874 lb) |
| notes | Type D brought about by change of rules | |||
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