Friday, February 4, 2011

1939 DKW F9 Prototype


In 1935 the DKW design team started work on a new car project. The 'hohe-klasse', or 'high class', was conceived as a wholly new design and was a quantum leap from DKW's budget car heritage. The driving force behind the project was DKW's realisation that Hitler's KDF-Volkswagen would come to dominate the budget car market in Germany by 1940 and if DKW were to survive, they needed a new car that could compete.

In 1937 the design was trialled in three streamlined, endurance racers. The cars featured a new chassis, new suspension and each car had a different engine - the standard 688cc two cylinder, two-stroke, the V-4 1000cc two-stroke, and a newly designed 896cc three cylinder two-stroke. This allowed the company to assess the performance of the new engine against its existing range. The trio performed well in the 1938 Rome-Berlin endurance race. http://heinkelscooter.blogspot.com.au/2013/08/auto-union-streamliners.html

After proving the new, streamlined design, Auto-Union adapted the concept for its Horch and Wanderer range. In 1938 Horch unveiled the stunning 930S streamliner, of which only a handful were built. Wanderer mocked up a mid-range car, but it was quickly realised that the new DKW model would fill that market and the project was suspended.

The bodywork of the Horch 930S was the first expression of Auto-Union's new streamlined styling.

Following the same naming/numbering convention as its predecessors, the new DKW was designated the F9. The cars' three cylinder two-stroke engine was of a wholly new design, that some people have claimed was modelled of the three cylinder Scott motorcycle two-stroke engine. Scott had developed the engine for a new motorcycle but the company went out of business after only a handful were built. DKW purchased a number of them and shipped them back to Germany. The engine developed 38hp and provided a maximum speed of 110 mph through a three speed gearbox.

To accommodate the new engine required a complete redesign of the bonnet layout. Like other DKWs, the car was front wheel drive. In the first prototype the engine was mounted transversely as in their earlier Front model cars, but the extra length of the engine made for an uncomfortable fit, so in the second prototype the engine was turned 90 degrees and mounted in line. To achieve the elegant sweep of the bonnet, the radiator was repositioned behind the engine, where it was cooled by a belt driven fan. There was however no water pump and the coolant circulated through the system by thermo-syphonic action. However, moving the radiator to the rear of the engine bay left no room for the petrol tank, which had traditionally been mounted above the engine against the firewall. Instead the fuel tank was moved to the boot, as in most modern cars, but this required the addition of a fuel pump - a novelty for DKW, which had previously relied on gravity feed in its cars and bikes. In accordance with DKW design principle of economy and simplicity, the fuel pump was a very basic affair that used the vacuum within the crankcase for its motive force. It was simple and it worked but it was something of a weak solution.

Contemporary advertising for the F9


Easy to drive, even for women! Note the gear lever is set in the middle of the dashboard.

Unfortunately, production of the F9 'hohe-klasse' was beset with unforeseen problems. As Europe began its inevitable slide towards war, Auto-Union's steel allocation - a scarce strategic resource in Nazi Germany - was substantially reduced, which required the DKW team to rework the design to allow substitution of the steel bodywork with a synthetic product called Duroplast. Duroplast was manufactured by pressing phenol resin impregnated wood pulp in a heated press. Once dried the wood panels were as strong and flexible as steel, but at a significantly lower cost. The process was developed in partnership with chemical company, Rommler AG and a specialist bodybuilder. DKW had begun using in the bodywork of F7s since 1938 as it simplified the production of complex curved body panels.

DKW's Duroplast bodywork panels on display at the 1938 Berlin Motor Show. Duroplast is probably most famous for its use in the Trabant, but DKW's Duroplast was developed differently to the later Trabant. The Trabant panels were manufactured with cotton waste.


Two prototypes on a test drive. This photo must have been taken during the early years of the War as both cars have their headlights masked and the left hand car has a black-out light over its headlight.

By September 1939 ten steel-bodied prototypes had been built and were being put through their trials. Preliminary advertising was prepared and the car was scheduled to go into production in early 1940. However, the start of the Second World War placed these plans on hold. The prototypes were distributed amongst DKW staff, including the car's designer, William Werner, who kept one of the cars for himself.

Colour advertising prospectus for the F9

Unfortunately most of the cars were destroyed during the War but three survived. One was recovered in Leipzig and became the template for the IFA F9. A body shell was found in the DKW karosserie works in Spandau and became the template for the DKW F89. The third car escaped from Chemnitz intact with William Werner when he fled to the West to avoid Soviet reprisals against Auto-Union's management. He settled in Oldenburg, near Bremen in the British Occupation Zone, but in 1946 the British Ministry of Supply seized his car and sent it to the School of Tank Technology in Cobham, Surrey. After a period of testing it was handed over to the Australian Army as part of the redistribution of German technology amongst the Allies.

The war had convinced the Australian Government that the country needed to develop an indigenous automobile industry and in 1944 proposed that Australia begin manufacturing "a car similar to the German low priced two-stroke DKW", so the British handed the car over to the Australians for the purposes of evaluation. Nevertheless, after extensive testing, the prototype, along with other confiscated German vehicles (including a 1946 Volkswagen), was put up for public auction in 1949 and sold.

Compare the rear view of the car with the Horch 930S above. They share the same stop lights and boot lid.

During the 1960s the car was owned by Mr Leo Redfern of Victoria, who made some modifications to the car. Being a prototype, replacement engine and chassis parts were impossible to find, so Leo transplanted the body to a DKW F8 chassis and engine.

The car changed hands a couple of times before it was tracked down by DKW aficionado, Peter T in the 1980s. Peter also obtained the original chassis and engine and planned to do a full restoration, but, personal circumstances intervened and he had to put the car up for sale. By this stage Audi AG had become aware of the surviving prototype and were keen to obtain this important vehicle for their collection. Forty odd years after it had left Germany the prototype finally returned home. Audi undertook the long awaited restoration, reuniting the body with its original engine and chassis. An early IFA F9 bonnet and grill replaced the missing original. The car is now on display at Audi's Ingolstadt museum where it can be enjoyed by everyone. http://www.audi.com/com/brand/en/experience/audi_forums0/audi_forum_ingolstadt/museum_mobile.html





The original 3=6 engine is substantially different in design from both the IFA F9 3=6 engine and the new DKW F91 3=6. Notable differences include the central placement of the belt/fan drives; the radiator pipe joining directly to the top of the engine, which is closely reminiscent of the earlier F8 layout; and the placement of the spark plugs at the side of the engine.

An early DKW F91 engine as comparison. The spark plugs are placed atop the engine, the radiator pipe and the belt/fan drive are both offset.

A mystery DKW engine discovered by Winfried Kuhl. It appears to be a 3=6 prototype engine but has a production serial number. Did DKW begin small scale production of the 3=6 engine in the mid-1940s?

F9 Successors
The prototype found in Leipzig after the war and was returned to the old DKW factory in Chemnitz, where it became the template for the East German IFA F9. 

The 1948 prototype IFA F9 at the Leipzig Motor Show. The newly restyled grill was quickly abandoned and the original pre-war style was reinstated.

In external appearance, IFA's F9 looks a faithful replica of the original F9, however there were some noticeable differences. The original F9 featured a rear mounted petrol tank, but for simplicity sake the IFA engineers initially placed the tank under the hood.

A peek under the hood of an early IFA F9. The petrol tank is placed behind the radiator, which removed the need for a fuel pump. The engine too is a new design.

The other survivor was a test body at the DKW bodyworks in Spandau. It was shipped to DKW's new factory in Ingolstadt, where it became the template for the DKW F89. DKW mounted the new body onto a modified F8 chassis. Not having access to the 3=6 engine, they continued to use the F8's two-cylinder 688cc engine. It's possible that DKW acquired a 3=6 engine from East Germany and reverse engineered the design. It wasn't until 1953 that DKW installed the new 3=6 engine in the F91.

The original DKW F89 prototype in Ingolstadt. Despite the oddly overblown bumper, the design closely resembles the original F9 design, especially in respect to the styling of the grill, however, as the IFA F9 already on sale, DKW were forced to restyle the F89.

No comments:

Post a Comment