Technical Paper
Turbocharging Small Displacement Spark Ignition Engines for Improved Fuel Economy
1979-02-01
790311
This paper describes an approach to improve the fuel economy of given cars with the aid of turbocharged SI engines of relatively small displacement, 1.6-l 4-cylinder and 2.2-l 5-cylinder configurations, to replace bigger, NA engines of the same power potential. This approach uses an engine turbocharger system which consists of a low-flow turbocharger in order to realize a given peak performance goal with good power characteristics over the entire engine-speed range. The boost pressure is controlled by a wastegate. The air/fuel mixture is prepared by a two-stage carburetor at the intake side of the TC compressor. The oxygen concentration in the exhaust gas is measured by an oxygen sensor upstream from a three-way catalyst.