Namyang, Korea — To help meet its goals of environmental leadership, Hyundai Motor Company today unveiled the 2.4 Theta II GDI, its first Gasoline Direct Injection engine before an audience of engineers attending the Ninth Annual Hyundai-Kia International Powertrain Conference.
Representing the biggest advancement in fuel injection, an '80s technology that replaced the carburetor, GDI puts Hyundai at the cutting edge of engine design and management by achieving three seemly incompatible goals: GDI lowers emissions while raising power output and improving fuel economy. Prior to GDI, a gain in one area came at the expense of the other two.
With a compression ratio of 11.3:1, the 2.4 Theta II GDI delivers 201 PS @ 6300 rpm and 25.5 kg-m @ 4250 rpm in its Korean domestic market specification.
“The Theta II GDI convincingly demonstrates Hyundai's advanced powertrain engineering capabilities,” said Dr. Lee Hyun-Soon, Vice Chairman and Chief Technology Officer.
Developed with a budget of 170 billion won over a 46 month-long research period, the new 2.4 Theta II GDI engine will make its debut in the first half of 2010 starting with the recently launched Sonata, beating the mid-size sedan competition to market with this exciting new technology. GDI application will subsequently be expanded across the gasoline engine family and applied to other Hyundai models.
One serious limitation of conventional fuel injection is that as engine revolutions increase, the valve opening and closing times get progressively shorter, thus reducing the time available to inject fuel. GDI avoids this problem altogether by positioning the fuel injector in the most optimal location, directly inside the combustion chamber to offer unparalleled precision. With this shorter and more direct path, far greater control is attained over the combustion process: A high pressure fuel pump injects the fuel at pressures of up to 150 bar, in precise amounts and intervals.
The injection is split into two phases to achieve optimum combustion: in the first phase, the pilot injection and ignition trigger the pistons downward power stroke. Then, in the main injection phase, during the pistons descent, more fuel is injected and is ignited. This split-injection technique reduces loading on the catalytic converter and helps lower emissions. This is particularly beneficial during cold starts when emissions are highest because the catalyst has not reached its optimal operating temperature. Split-injection enables the catalytic converter to reach the optimal operating temperature faster thus reducing emissions by 25 percent during cold starts and meet's California Air Resources Board's ULEV-2 and PZEV standards.
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Tags: 4-cylinder, direct-injection, GDI, Hyundai, Sonata, Theta
Since fuel-injection was introduced in 1957 rather than the ’80s, it’s perhaps not surprising that Hyundai is not aware that GDI dates back to the previous millennium in midsize sedans (the 1996 Mitsubishi Galant/Aspire). In this millennium GDI has been used on 4-cylinder engines in the Ford Mondeo, Opel Vectra and Signum, Nissan Bluebird and Primera, Toyota Avensis, Premio and Allion, Mitsubishi Galant, Buick Regal, Opel Insignia, Volkswagen Passat, Volkswagen Magotan, Skoda Superb, BMW 520i, Mercedes E200 and E250 CGI, Alfa Romeo 156 and 159, Audi A4 and A6 and SEAT Exeo. I’ve probably left some out. Certainly by the time the GDI Sonata is available there will at least be the Buick LaCrosse with 2.4 GDI as well. With 6-cylinder GDI engines there have been and are even more midsize sedans.