A HISTORY OF TURBOS:
FORCED AIR AND DIESELS, THEN AND NOW
ENGINEERS HAVE worked hard at improving internal-combustion engines since the advent of the powerplants, way back in the late 1800s. Gottlieb Daimler and Rudolf Diesel, two of the first true players in the field of engine development, worked on ways to increase power output while reducing fuel consumption in their engines. Daimler tinkered with a geardriven pump for forced air induction as early as 1885.
However, it wasn’t until 1905 that turbochargers began to take shape, when Swiss engineer Alfred Büchi (head of diesel engine research at Gebrüder Sulzer) received a patent for a compressor driven by exhaust gases that forced air into a diesel engine to increase power output. It took Alfred until 1925 to get the first successful exhaust-gas turbocharging system effectively applied to an engine, resulting in a more than 40 percent power increase. These early units were referred to as turbosuperchargers. At the time, all forced-induction devices were classified as superchargers.
A lot of the early advancement was hindered by the metal and bearing technology available. The materials were unable to withstand the tremendous amount of heat and forces exerted on them. As better metals became available for turbochargers, the devices were initially applied on large marine diesel engines. In 1923, two German passenger liners (the Danzig and the Preussen)
were the first (vehicle or vessel) to be outfitted with turbodiesels. The ships’ 10-cylinder engines were able to muster 2,500 hp, while their normally aspirated counterparts could only produce 1,750 hp. With the benefits of the application proven, manufacturers began applying the technology to stationary and locomotive oil-burners.
Also during the early years, aircraft engines were being set up with ’chargers to test the way they benefited those powerplants’ performance when subjected to high altitude. In 1918, General Electric engineer Sanford Alexander Moss attached a turbocharger to a V-12 Liberty engine and demonstrated it at Pikes Peak in Colorado at 14,000 feet. He showed how forced induction counters the power loss brought on by the effects of reduced air pressure and density at high altitude. Two years later, a turbocharged 12-cylinder Liberty was mounted in a Le Pere biplane and flown to 33,000 feet with no loss of boost.
In 1936, Dr. Werner Theodor von der Nuell started to research the first variable-geometry turbochargers (also known as variable-nozzle turbines) at the Laboratory for Aviation in Berlin, Germany. It was not until after World War II that these units were really sought after. Across the pond in the U.S., J. C. “Cliff” Garrett was just starting to build his business, with the production of turbochargers and charged-air coolers for aircraft companies like The Boeing Company and Grumman Aircraft Engineering Corporation.
The technological advances in materials and designs during World War II and development of the gas turbine lead to further advancement of turbochargers. They could be made more compact and reliable and better suited for smaller higherspeed engines. The new units were first applied on diesel-truck engines. Even before the war in 1938, Swiss Machine Works Saurer developed the first turbocharged powerplant for a truck.
In 1954, MAN and Volvo became the first truck builders to introduce production vehicles powered by turbocharged diesels. Tractors and construction equipment also experienced the implementation of turbos. Companies like Caterpillar understood the benefit of an increase in power and fuel savings. The 1950s also ushered in the development of the Interstate Highway system in the U.S., which fueled the need for trucks that could keep up with traffic while hauling heavy payloads. This prompted engine builders such as Cummins, Detroit, and Caterpillar to begin offering turbos as an option by the late 1960s. In Europe, manufacturers Scania and Volvo met German power-to-weight truck regulations by turbocharging all their engines.
Turbocharging was not initially received well. Many felt it was less reliable than normal aspiration and the high investment cost was only offset by fuel savings. That changed during the first oil crisis in 1973, when improved technology showed increased fuel mileage and performance could be achieved. The growing concern about emissions in the 1980s helped further boost turbos’ use to the point where almost every truck engine today is equipped with one.
Smaller automotive turbodiesels were first experimented with in the 1960s by the Rover Company, which researched a 2.5L I-4 equipped with and without an intercooler. The ’78 Mercedes-Benz 300 SD is the first passenger car to use turbocharging in the U.S. The engine uses a Garrett AiResearch boost provider. In Europe, the Peugeot has the privilege of being first.
It wasn’t until the 1990s that light trucks built in the U.S. were regularly outfitted with turbocharged diesel engines. Actually, in 1989, Dodge began using the 5.9L Cummins engine in its Ram pickups, becoming the first truck manufacturer to use a turbodiesel. A few years later (in 1992), General Motors debuted the turbocharged 6.5L Detroit Diesel V-8 powerplants in its trucks. Then Ford followed suit with the 7.3L Power Stroke V-8 in 1994.
While the turbocharger struggled for a while to be used regularly on diesel engines, today it is hard to think of an oil-burner that does not have at least one turbo. We believe the benefits of using boost, coupled with the technological advances of modern powerplants, anchors the use of turbochargers on engines for many years to come.
BorgWarner Turbo Systems
STK Turbo Technik