Tatras 77

Tatra Mountains
Tatras 77
T77
Production period:	1934-1938
Class :	Upper class
Body versions :	limousine
Engines:	Otto engine : 3.0 liters (44 kW)
Length:	5130-5410 mm
Width:	1700 mm
Height:	1500 mm
Wheelbase :	3150-3250 mm
Empty weight :	1700-1800 kg
successor	Tatra Mountains 87

Tatra 77 A

The Tatra 77 is a passenger car of the superclass with air-cooled eight-cylinder - V-engine of the Czechoslovak manufacturer Tatra . It was produced in two series from 1934 to 1938 and was one of the first series- produced automobiles whose body was designed based on the knowledge of aerodynamics and tested in a wind tunnel. The drag coefficient C _wof 0.245 for a 1: 5 scale model, 0.38 for the Tatra 77 and 0.33 for the Tatra 77a were very low for motor vehicles at that time. The successor was the much more modern and faster Type 87 , which was built in parallel for two years from 1936 .

history

prehistory

In 1931, after tests with the small prototype of a rear-engined car V 570 , Tatra began developing new, large and luxurious passenger cars with low air resistance under great secrecy. In addition, the second version of the V 570 in 1933 received a first, conditionally aerodynamic body, which was used as a basis for further work. The Type 77 prototype was the first car to have a model tested in the wind tunnel , which had previously been used to improve the shape of aircraft and airships . The intellectual fathers of this and a number of other Tatra cars of the same design were Hans Ledwinka as the company's chief designer for technology and engineer Erich Übelacker (1899–1977) for the streamlined body. The design of the body is largely based on the ideas and findings of the Hungarian engineer and aerodynamicist Paul Jaray .

Type 77

The Tatra 77 was presented to the public on March 4, 1934 at the Prague Motor Show. Production started in the same month. It was the world's first mass-produced streamlined automobile and its appearance on the auto market caused a sensation. Since the car was supposed to be low and the floor of the car as smooth as possible, the engine was placed in the rear, which meant that the conventional cardan tunnel with the exhaust pipe could be omitted. The central support tube typical for Tatra was retained. It was characterized by the vertical rear central fin, which was intended to compensate for the effects of crosswinds on the light front end in order to improve straight-line stability . The T 77 was powered by an air-cooled V8 engine in the rear with 2969 cm³ displacement , (75 mm bore, 84 mm stroke), a compression of 5.3: 1, overhead camshafts and an output of 60 hp (44 kW) 3500 rpm. The power was transmitted to the rear wheels via a partially synchronized four-speed gearbox. Housing parts of the engine and transmission were made of a magnesium alloy. All the wheels were individually suspended, on double wishbones at the front and a pendulum axle at the rear . Both axles had transverse leaf springs. There were hydraulically operated drum brakes at the front and rear. The top speed was 145 km / h. 101 of these cars had been built by 1935.

Type 77 A

In 1935 it was further developed into the Type 77 A. This was 100 kg heavier, had a wheelbase longer by 10 cm, an engine bored out to 80 mm with a larger displacement (3378 cm³) and higher engine power (70 HP (51 kW) at 3500 rpm), slightly improved driving characteristics and a top speed of over 150 km / h. The Type 77 A can be easily distinguished from its predecessor by the third front headlamp arranged in the middle - for the first time in a Tatra. When the improved successor, the Type 87 , appeared in 1936 , the T 77 A was not discontinued, but continued to be built in 154 units until 1938 due to continued interest.

A total of 255 vehicles of the Type 77 and Type 77 A in all versions (without prototypes) were produced, whereby, due to the frequently realized customer requests, hardly any car was like the other.

Nowadays, the Tatra 77 , especially in its second version, is a sought-after collector's car or classic car .

variants

• Tatras 77
• Tatra 77 A

Technical specifications

Type 77 built between 1934 and 1935

• Length: 5130 mm
• Width: 1700 mm
• Total height: 1500 mm
• Wheelbase: 3150 mm
• Front track: 1300 mm
• Rear track: 1300 mm
• Ground clearance: 220 mm
• Engine: V8 engine with OHC valve control , air-cooled (2 axial cooling fans)
• Displacement: 2969 cm³
• Output: 60 hp (44 kW ) at 3500 rpm
• Max. Torque: 132 Nm at 2400 rpm
• Gearbox: single-disc dry clutch (Komet Mecano type), four-speed manual gearbox with center shift, 3rd and 4th gear synchronized
• Drive type: rear-wheel drive
• Empty weight 1700 kg
• Top speed 145 km / h (factory specification)
• Standard consumption: 14-16 l / 100 km

Type 77 A built in 1935–1938

• Length: 5410 mm
• Width: 1700 mm
• Total height: 1500 mm
• Wheelbase: 3250 mm
• Front track: 1300 mm
• Rear track: 1300 mm
• Ground clearance: 220 mm
• Engine: V8 engine with OHC valve control, air-cooled (2 axial cooling fans)
• Displacement: 3378 cc
• Output: 70 hp (51 kW) at 3500 rpm
• Max. Torque: 148 Nm at 2400 rpm
• Gearbox: single-disc dry clutch (Komet Mecano type), four-speed manual gearbox with center shift, 3rd and 4th gear synchronized
• Drive type: rear-wheel drive
• Empty weight 1800 kg
• Top speed 150 km / h (factory specification)
• Standard consumption: 14-16 l / 100 km

literature

• Ivan Margolius & John G Henry: Tatra - The Legacy of Hans Ledwinka , Veloce, Dorchester 2015. ISBN 978-1-845847-99-9 .
• Larry Edsall, Valeria Manferto: Legends of automotive history from the beginning to the 21st century. Wiesbaden White Star Verlag 2006, ISBN 3-939128-52-X , pp. 40-43.

Web links

Commons : Tatra 77  - collection of pictures, videos and audio files

• Pictures and drawings of Tatra 77 and Tatra 77 A at the TATRA AUTO KLUB SLOVAKIA

Individual evidence

1. ↑ http://www.tatraplan.co.uk according to the source it is a measurement in the Wolfsburg climatic wind tunnel
2. ↑ http://www.tatraportal.sk/data/popisky/t77/a/t77a_17.jpg
3. ↑ http://www.tatraportal.sk/?ukaz=popisky/t77_sk