In the mid-1930s, a Czechoslovak car maker produced one of the fastest and most aerodynamic cars of the era. David Cooper and Pál Négyesi share the story of the Tatra 77 and its descendants.
Ledwinka Hires Jaray
When the time the Great Depression hit Czechoslovakia, Tatra was working to develop a successor to its popular T12 model. Hans Ledwinka’s vision, combined with the company’s desperate effort to expand their sales, led to the development of the streamlined T77/T87/T97 range. Ledwinka invited Paul Jaray as a body design consultant. The development team also included Hans’ oldest son, Erich, and a German engineer, Erich Übelacker. Together they worked on a new small car, code named V570. Eventually, two different directions emerged – a conservative approach led to the T57, which built on Tatra’s earlier drive-train innovations, but lost the aerodynamic body shapes suggested by Jaray. The other more radical direction was to build a line of new cars with aerodynamic bodies following Jaray’s principles. In the early 1930s, many designers, including Ledwinka, believed that streamlining, or aerodynamics, along with technological advancements, permitted the construction of a new form of high-speed luxury travel between cities by private automobile. The ultimate goal was an efficient and elegant 160 km/h (100 mph) touring car that was safe, comfortable, and quiet. Tatra decided that their first offering would be a full size luxury car built on aerodynamic principles that could appeal, and sell to, a broader Western European market. Ledwinka and his team moved quickly to develop their radical new designs.
In 1933, Ledwinka constructed a prototype vehicle with everything at the back – air-cooled engine and transmission/drivetrain — but, because of the extreme rear weight bias, it was a bit unstable. He also built several prototypes of a new air-cooled V8 engine. These prototypes laid the foundations for the T77-T87-T97 trio.
The T77 Appears
The new T77, introduced in 1934, incorporated a three-part panoramic front window, fully independent suspension, a rear-mounted air-cooled V8 engine with hemispherical combustion chambers, and a dry sump. The team used a wind tunnel, working closely with Jaray, and studied the ideas of designer John Tjaarda to fine-tune the new car’s streamlined shape. However, the T77 had sharper corners and flatter panels than Jaray’s original concept. Two large fans cooled each cylinder bank of the rear V8 engine. They drew air from the two scoops on the roof and hot air was exhausted through fins in the engine cover. The advantages of having the engine mounted in the rear were (1) aerodynamic efficiency due to the low frontal area; (2) reducing noise, fumes, and heat from the passenger compartment; (3) a flat floor due to the elimination of the driveshaft; and (4) service accessibility, as the entire drivetrain could be removed from the car quickly and easily.
Because the air-cooled engine did not need a front radiator, Tatra could design an innovative low curved shape for the front of the car to achieve a remarkably low drag coefficient. This was a bold design move because buyers were used to the radiator’s traditional look defining the front shape of a car. In the United States, Franklin, who was also known for their air-cooled engines, was forced to add a fake radiator because people were reluctant to buy something different. The Chrysler Airflow, introduced at the same time as the Tatra T77, also had a radical shape that was hard to sell. Ironically, the T77 and the Airflow have even more in common. Ledwinka’s cousin Joseph, who worked for the Edward G. Budd Manufacturing Company, the Airflow coachbuilder, helped design the 1934 Chrysler’s Art Deco waterfall shape front hood, which echoed the curved front shape of the T77.
Tatra designed a chassis that lowered the center of gravity for better handling.The chassis had a central rectangular tube formed of sheet metal with outriggers to hold the body, that evolved into a Y shape at the rear to hold the eight-cylinder engine. Tatra pioneered lightweight Elektron, an aluminum/magnesium alloy, for the crankcase, differential housing, intake manifolds and many small parts. Elektron is still used today for airplanes and space equipment. Though in the prototype the gearbox was also made from Elektron, in the production version Tatra used cast iron.
The weight bias of the rear engine gave superior traction over the tires. While the production cars were improved over the intial prototypes, they still suffered a shortcoming common to all rear-engine cars, they oversteered when exceeding cornering limits, which could overwhelm an inexperienced driver. Porsche later spent decades trying to design ways to overcome this shortcoming. With an overall length of 5200 mm and a width of 1600 mm, the T77 had a kerb weight of 1,7 tons. The Tatra 77 was available with a leather or cloth interior. Some cars had a glass partition between the front and rear seats. A sliding roof was available. In one of the development prototypes, Tatra experimented with a central mounted steering wheel, but this never made it into the production cars. In this prototype, the front-seat passengers were seated on either side of the driver, and the seats placed slightly rearwards.
The innovations in the T77 made a strong impact around the world, especially in France, when the production car was introduced at the Paris Salon in October 1934, following a debut of the prototype earlier that year in Berlin. While the Tatra T77 was an engineering masterpiece, it was not beautiful in the way we find the 1936 Bugatti Atlantic. However, its design’s elegance led directly to the Volkswagen Beetle, the Porsche 356 and 911, and the Tucker Torpedo. Tatra’s ideas influenced most car designers and helped inspire the great streamlined cars of the 1930s.
The T77 achieved Tatra’s sales objectives with sales of 255 examples in two series from 1934 to 1938. The second series T77a featured an enlarged engine capacity of 3380 cc, which raised horsepower from 60 to 75. This was a small engine by luxury car standards of the era. Still, thanks to the larger displacement and the Zenith 36 DIB carburetor, the efficient T77a could easily reach a speed of 140 km/h! But Tatra was interested in larger sales, and this led to the development of a successor model that could be built and sold at less cost, and reach an even larger market.
Read more of this story in the first issue of Rare & Unique Vehicles, which will be out on 7 December. It will not be sold at newsstands, so make sure to subscribe! More details: rareandunique.media