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Corvette Glossary Of Terms – E

c5 corvette

Corvette Glossary Of Terms



Earl, Harley J.

November 22, 1893–April 10, 1969 – was the first Vice President of Design at General Motors. He was an industrial designer and a pioneer of modern transportation design. A coachbuilder by trade, Earl pioneered the use of freeform sketching and hand sculpted clay models as design techniques. He subsequently introduced the “concept car” as both a tool for the design process and a clever marketing device.

Influenced by the English and European sports cars being raced on road racing circuits after World War II, Earl decided that General Motors needed to make a sports car. Design work on “Project Opel” began as a secret project. He first offered the project to Chevrolet general manager Ed Cole.  Cole accepted the project without hesitation, and the car was offered to the public in 1953 as the Chevrolet Corvette.

Harley Earl retired from General Motors in 1958 after overseeing the design of the 1959 models. He was succeeded as vice-president with responsibility for the Design and Styling Department by Bill Mitchell, under whose leadership GM design became less ornamental.  Before Earl retired, General Motors became the largest corporation in the world, and design was acknowledged as the leading sales factor within the automotive industry. Harley Earl’s biographical content courtesy of Wikipedia. Corvsport Page References: C1 Overview, 1953 Overview, 1954 Overview, 1955 Overview1956 Overview, 1958 Overview, 1960 Overview1962 Overview.

Eaton TVS Supercharger

Eaton’s new Twin Vortices Series (TVS) is a Roots-type supercharger for a variety of engine applications that delivers more power and better fuel economy in a smaller package, for uncompromising, high-performance driving.

The TVS supercharger’s patented design features four-lobe rotors and high-flow inlet and outlet ports that greatly enhance thermal efficiency, deliver higher volumetric capacity, and enable higher operating speeds. The TVS supercharger is capable of running with a high thermal efficiency (up to 76 percent) across a very wide operating range. Corvsport Page References: 2009 ZR1 Overview.

Engine Control Module (ECM)

Also known as a power-train control module (PCM), or engine control unit (ECU), the engine control module (ECM) is a type of electronic control unit that determines the amount of fuel, ignition timing and other parameters an internal combustion engine needs to keep running. It does this by reading values from multidimensional performance maps (so called LUTs), using input values (e.g. engine speed) calculated from signals coming from sensor devices monitoring the engine. Before ECU’s, air/fuel mixture, ignition timing, and idle speed were directly controlled by mechanical and pneumatic sensors and actuators. Content courtesy of Wikipedia.


The U.S. Environmental Protection Agency (EPA or sometimes USEPA) is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress.  The EPA was proposed by President Richard Nixon and began operation on December 3, 1970, after Nixon submitted a reorganization plan to Congress and it was ratified by committee hearings in the House and Senate.  The agency is led by its Administrator, who is appointed by the president and approved by Congress. The current administrator is Lisa P. Jackson.  The EPA is not a Cabinet department, but the administrator is normally given cabinet rank. The agency has approximately 18,000 full-time employees.  Content courtesy of Wikipedia. Corvsport Page References:  1986 Corvette.


The official designation of the first of the hand-built Corvettes developed by Harley Earl and his design team.  The EX-122 concept car, which had been in development since 1951, made its world premier at the GM Motorama in New York City on January 17, 1953.  The EX-122 prototype was met with such resounding success that Chevrolet took its design to production almost immediately, and made virtually no changes to the car during the first two years that the Chevrolet Corvette was manufactured. Corvsport Page References: C1 Overview.