Thread: Aura Greenline
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Old 08-02-2006, 12:25 PM   #5
derek77
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Default Re: Aura Greenline

Nickel Metal-Hydride (NiMH) Battery
A NiMH battery pack powers the GM Hybrid’s MGU in motor mode, and is recharged by the MGU in generate mode. The battery delivers 14.5 kW peak power. Until recently, NiMH battery technology was reserved for wrist watches and small electronic appliances like telephones. In a sense, the GM Hybrid NiMH battery is like a giant watch battery, with an anticipated useful life of at least seven years. As hybrid vehicle batteries go, it is compact, and does not significantly hamper utility.

E67 Engine Control Module
GM’s new E67 Engine Control Module (ECM) manages all systems in the Ecotec 2.4L Hybrid, including both MGU and gasoline engine operation. It’s one of three ECMs in a family that will run nearly all the engines in GM Powertrain’s line-up. The E67 features 32-bit processing, compared to the conventional 16-bit processing in previous Ecotecs. It operates at 59 MHz, with 32 megabytes of flash memory, 128 kilobytes of RAM and a high-speed CAN bus. It synchronizes hundreds of functions, from spark timing to cruise control operation to MGU management.

The E67 validates the family strategy behind GM Powertrain’s latest ECMs. While it adds unique Hybrid Supervisory software for the 2.4L Hybrid, it’s identical to the controller that directs such engines as the 4.4L Northstar V8 SC in the Cadillac XLR-V
Common controllers reduce development costs. The family of ECMs allows engineers to apply standard manufacturing and service procedures to all powertrains, and to quickly upgrade certain engine technologies while leaving others alone. They create both assembly and procurement efficiencies, as well as volume sourcing. In short, the new family of controllers creates a solid, flexible, efficient foundation, allowing engineers to focus on innovations and get them to market more quickly.

Cooled Power Electronics
The Ecotec 2.4L Hybrid power electronics do very sophisticated work in a demanding environment. They repeatedly switch the MGU from motor to generator in fractions of a second, cycle current in different directions, invert DC battery power to three-cycle AC and vice-versa, all the while sorting 12-volt DC to power accessories, and they do this inside an engine bay where extreme heat and a multitude of vibrations of various frequency are a fact of life. To stack the odds, GM Powertrain engineers have secured the 2.4L Hybrid’s voltage regulator, MGU controller, inverters and other components in a vibration-dampened aluminum shell the size of a small briefcase. The case is mounted to the right side of the engine ( as seen from the front of the vehicle )and fed with coolant tapped from the front of the cylinder block.

Seven-Rib High Strength Crank Pulley
In combination with the Ecotec 2.4L Hybrid’s high-torque accessory drive system, the engine is equipped with a high-strength crank pulley that matches the drive belt’s seven-rib design. Other accessory pulleys are also more robust.

Dual Catalytic Converters
The Ecotec 2.4L Hybrid uses two catalytic converters, including a close-coupled, fast light-off catalyst just past the exhaust manifold in the exhaust stream. Because the exhaust ports and exhaust manifold heat more rapidly than any part of an engine, moving a smaller catalytic converter closer to the manifold in turn allows the catalyst to heat more quickly. So positioned, the catalytic converter achieves light-off—the temperature at which exhaust emissions are most efficiently oxidized--more quickly. This considerably lowers emissions during cold starts—a brief period when an engine operates at its highest emissions level and a critical phase in government certification tests.


Overview

The Aura’s hybrid system coupled with the Ecotec 2.4L Hybrid engine will deliver a considerable fuel economy improvement compared to a conventionally powered Auras, yet it’s price premium is expected to be much lower compared to other hybrids.

The Ecotec 2.4L Hybrid engine takes a simple, straightforward concept and executes it with sophisticated technology. Its internal-combustion engine is based closely on the Ecotec 2.4L VVT (RPO LE5) introduced for model year 2006 in several cars and trucks, including the Chevrolet HHR and Pontiac Solstice, and it further validates the strategy behind the Ecotec line of four-cylinder engines.

Often referred to as the global four cylinders, the Ecotecs harness GM Powertrain’s global design and engineering capability by applying the best practices of technical centers in Europe and North America. The Ecotec 2.2L (RPO L61) created a blueprint for subsequent global powertrain development. It also laid the foundation for a line of engines that share core components with minimal casting changes, yet deliver unique performance and market characteristics with a range of displacements, fuel-delivery and induction systems and front-, rear- and all-wheel drive applications in both cars and trucks. Since launch of the original Ecotec in 2000, turbocharged and supercharged engines, others with full two-cam phasing and direct gasoline injection--and now a hybrid-- have been developed on the same basic architecture.

The Ecotecs have undergone the most demanding, comprehensive test and validation process in GM history, and the 2.4L Hybrid engine demanded even more. This engine will conceivably be started and stopped in excess of a million times over its life, and GM Powertrain conducted additional lab and vehicle tests to make sure it was up to the job. It certainly is, and without the need for additional durability enhancements specific to the hybrid.

With good specific output, acceleration assist from its MGU and the broad torque delivery that comes with fully variable valve timing, this hybrid delivers good performance. Factor in the 20 percent fuel mileage improvement at a reasonable price, , and the message is clear. The Ecotec 2.4L Hybrid makes in very easy to be green.


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