Amazing Innovations: Turbochargers

January 13, 2014
Story By
Evan Griffey

Cheating physics is a good thing. When it comes to the internal combustion process I always say the more you can fool physics the better. The turbo is the ultimate trickster; pressurizing the intake charge in the name of ungodly power production. It is one of the most innovative forces in the automotive mainstream and one of the few that can be harnessed to enhance performance and fuel efficiency, two normally antagonistic objectives.

It didn’t take long after the establishment of internal combustion for thelight bulb was is the idea of forced induction to spark to life. But it would take time for the technological principles, materials, and pioneering spirit to make it materialize. Around 1890 Gottlieb Daimler and Rudolf Diesel tussled with the idea of “pre-compressing” the combustion charge but it was Alfred Büchi, a Swiss engineer and techno-geek, who put it together in three dimensions. In his 1905 patent his “highly supercharged compound engine” used an “axial compressor, radial piston engine, and an axial turbine in accordance with a common shaft.” It took until 1915 for Büchi to develop a prototype. It was an utter failure but the lessons learned led to his ultimate success in 1925 when he turbocharged a diesel engine, boosting its efficiency by an impressive 40 percent. Primitive turbo systems were employed on big, expensive industrial and marine engines and turbos didn’t permeate into the automotive realm until about 1938 when they were employed on trucks. The race to be the first factory turbocharged passenger car was close but either way General Motors gets the glory. The 1962 Oldsmobile JetFire is mostly credited with being the first but some claim the Chevy Corvair is heir to the throne. The Olds JetFire was motivated by the Turbo Rocket V8, an engine that generated 215 horsepower from 215 cubic inches. A Garrett AiResearch T5 provided the pressure, a scant five psi.

first-turbocharged-car-1962-Oldsmobile-Jetfire-Brochure

The Turbo Rocket V8 sputtered for two main reasons; its compression ratio and the dramatic disconnect between carburetors and boost pressure. It was ahead of its time…and ahead of the technological principles needed for harmonious operation. The Olds ran a draw-through set-up where incoming intake air is pulled into the carburetor where it is joined by fuel then the resulting air/fuel mixture is sucked through the turbo and blown into the engine. It was hard to properly meter the fuel in this pressurized environment and produce consistent fuel flow with a carb set-up…even at a measly five pounds of boost.

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The V8’s 10.25:1 compression ratio resulted in detonation or pre-ignition events, innocuously called knocking or pinging. Controlling the timing of the combustion event is key to a smooth running engine. During pre-ignition the air/fuel mixture is too hot and fires off early, before the piston is ready for its power stroke. This is not good. Olds employed its Turbo Rocket Fluid system which sprayed an alcohol/water mixture into the intake tract to cool the charge. The set-up required owners to keep the system’s tank full of fluid. They didn’t and complications ensued. All this and considering the fact that a 394 cubic inch Sky Rocked V8 pumped out 330 carefree ponies and the turbo engine lost its appeal and soon dropped below even novelty status. Turbocharging made its mark in diesel pickups but in my opinion turbos started their climb to relevance in the passenger car realm with the introduction of fuel injection. This advance culminated with the emergence of electronic fuel injection in the 1984 to 1987 Buick Grand National. I worked at Turbo magazine in the early ‘90s and owned the GN pictured here and can attest to the prowess of these black beasts.

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With fuel being introduced at the combustion chamber there was no drama in developing a stable intake charge, computer engine control exponentially increased the precision of the combustion process, and the rest, as they say, is history. Ads of the day claimed “Run 12s for $600 and they meant it. Buick was understandably conservative with the 235-horsepower, 3.8-liter V6 so there was plenty of tuning meat left on the bone for the aftermarket. Today the turbocharger is both a fuel consumption aid and an out-and-out power producer… a win-win for tree huggers and right foot stompers alike. To me its significance as an innovator can be seen in the specific output of some of today’s modern turbocharged performance engines; Porsche 911 GT2 RS 620 horsepower, 3.6-liters, 172 horsepower per liter, Mitsubishi Lancer Evolution X, 291 horsepower, 1,998 cc, 145.6 horsepower per liter, Nissan GT-R, 545 horsepower, 3,799 cc, 139.5 horsepower per liter. Daimler, Diesel, and Büchi would wet their pants.

Amazing Innovations: Turbochargers

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