MODEL DETAILS
What: Auto Union Type D Grand Prix
Manufacturer: Auto Union AG, Racing Department (Horch Works, Zwickau)
Genre / Series: Grand Prix Racing
Category: 850 kg Formula
Era: Auto Union prewar
Model Family:
Market / Zone: International Motorsport
Season: 1938
Number Produced: 11 chassis (1938–1939)
Model / Generation Code(s): Type D
Chassis / Matrix:
Designer: Dr. Ing. Robert Eberan von Eberhorst
TECHNICAL DETAILS
Body Style(s): open-wheel single seat racecar
Chassis Type: Tubular ladder-type frame with aluminium bodywork
Drivetrain Configuration: longitudinal rear mid-engine, rear-wheel drive
Engine(s): Supercharged V12, 60° bank angle
Displacement: 3.0 litres (2,986cc)
Valvetrain:
– Three cam shaft (central single camshaft for the intake valves and two separate overhead camshafts for the exhaust valves)
– 24 valves total (2 valves per cylinder)
Fuel: High-octane racing blend (alcohol-based racing blend)
Induction: Single-stage supercharger
Power: approx. 420 horsepower
Torque: 550 Nm (or about 406 lb⋅ft)
Cooling: advanced, highly pressurized water-to-ethylene-glycol cooling system
Top Speed: 205 mph (approximately 330 km/h) depending on gearing and circuit
Transmission(s): 5-speed manual transaxle, non-synchronized transaxle paired with a limited-slip differential
Differential: ZF limited-slip differential
Wheelbase: 2,800 mm (approximately 110.2 inches)
Width: 1,660 mm (about 65.4 inches or 5.45 feet
Length: 4,200 mm (about 165.4 inches or 13.78 feet)
Height: 1,060 mm (41.7 inches)
Weight (dry): ≤ 850 kg (regulatory limit; 850 kg (approx. 1,874 lbs)
Tires: high-speed, grooved or slick racing tires manufactured by Continental
Wheel Size: staggered wire-spoke wheels, using 17-inch rims on the front and 19-inch rims on the rear
(Note: Dimensions varied slightly depending on circuit and hill-climb bodywork.)
DRIVERS (SELECTED)
• Tazio Nuvolari
• Hermann Paul Müller
• Hans Stuck
• Rudolf Hasse
• Christian Kautz
• Ulrich Bigalke
• Ewald Kluge
OVERVIEW
The Auto Union Type D was the final evolution of the famed Auto Union Silver Arrow Grand Prix cars and the last Auto Union racing car developed before the outbreak of World War II. Introduced for the 1938 season in response to new international Grand Prix regulations limiting supercharged engines to 3.0 liters, the Type D replaced the marque’s earlier V16-powered Type A, B and C models with a newly developed supercharged V12 engine.
Designed under the direction of engineer Robert Eberan von Eberhorst, the Type D retained the revolutionary rear-engine layout pioneered by Auto Union and originally conceived by Ferdinand Porsche. The configuration placed the engine behind the driver but ahead of the rear axle, a concept that would not become commonplace in Grand Prix racing for another two decades.
The Type D competed during the 1938 and 1939 Grand Prix seasons and was driven by some of the era’s most notable racers including Tazio Nuvolari, Hans Stuck, Rudolf Hasse, Hermann Paul Müller and Georg Meier.
DEVELOPMENT
For 1938, Grand Prix regulations reduced maximum engine displacement for supercharged cars from 750 kilograms formula unrestricted engines to a 3.0-liter supercharged limit. Auto Union responded by developing a new 60-degree V12 engine displacing 2,986 cc. Early versions produced approximately 420 horsepower, while a twin-stage supercharged evolution introduced during 1939 increased output to approximately 485 horsepower at 7,000 rpm.
The Type D featured independent front suspension, a de Dion rear axle and centrally located fuel tanks within the wheelbase to improve handling balance. These developments represented a substantial departure from the earlier Type C and were intended to address the challenging handling characteristics for which the earlier Auto Union racers had become known.
COMPETITION HISTORY
The 1938 season marked the competitive debut of the Auto Union Type D under the new 3.0-liter Grand Prix regulations. Following the death of Bernd Rosemeyer earlier that year, Auto Union entered the season in transition, fielding a driver lineup that included Hermann Paul Müller, Rudolf Hasse and Christian Kautz before later strengthening the team with Hans Stuck and Tazio Nuvolari.
Development of the Type D proved challenging during the early part of the season as engineers worked to tame the handling characteristics of the rear-engined chassis and extract performance from the new supercharged V12 engine. By mid-season the car had become increasingly competitive against the dominant Mercedes-Benz W154.
The turning point came with the arrival of Tazio Nuvolari. Joining Auto Union during the summer of 1938, the Italian quickly adapted to the unconventional Type D and delivered one of the most celebrated victories in the marque’s history at the Italian Grand Prix at Monza on 11 September 1938. Driving against the factory Mercedes-Benz team on home soil, Nuvolari guided the Type D to victory before an enthusiastic Italian crowd.
Nuvolari followed that success with another landmark victory at the Donington Grand Prix on 22 October 1938. Held before a crowd of more than 60,000 spectators, the race saw Nuvolari defeat the favored Mercedes-Benz entries after setting the fastest lap of the event. The victory was Auto Union’s final major international Grand Prix triumph before the outbreak of World War II and remains one of the most famous performances of Nuvolari’s career.
Additional strong performances came from Hans Stuck, Hermann Paul Müller and Rudolf Hasse throughout the season as Auto Union continued refining the Type D. By the end of 1938, the car had established itself as a genuine rival to Mercedes-Benz and laid the foundation for the improved twin-supercharged Type D that would compete during the final pre-war Grand Prix season in 1939.
LEGACY
The Auto Union Type D represented the culmination of Auto Union’s pre-war Grand Prix program and the final competitive expression of the original Silver Arrow era. Its rear-engine layout, advanced suspension design and supercharged V12 powertrain were decades ahead of contemporary practice and influenced the future direction of Grand Prix car design. Today, surviving Type D examples are among the most valuable and historically significant racing cars in existence.
PHOTO GALLERY
