Chevrolet Camaro V6 gets power boost from integrated exhaust manifold

General Motors has managed to wring out more horsepower from its 3.6-liter direct-injection V6 and get better fuel economy, too. And the 2012 Chevrolet Camaro gets the benefits.

It starts with the old Lotus adage of adding lightness. Thirteen pounds of engine weight were shed by integrating the cylinder head and exhaust manifold into one cast-aluminum part.

The integrated design increases airflow through the engine and eliminates the joint and gasket between the head and manifold.

Testing proved that intake airflow has improved 7 percent while exhaust flow is 10 percent better than in the previous V6.

Aside from increased fuel economy, the new heads help provide more power to the wheels. The 2012 Camaro with the V6 makes 11 hp more than last year's engine, bringing it to 323 hp.

"Reducing engine mass of this magnitude doesn't often happen," said Ameer Haider, GM assistant chief engineer for V6 engines. "Engineering usually looks for a reduction in terms of grams, not pounds. It's like removing a set of golf clubs from your car when you don't need them--ultimately, it saves fuel."

The change also results in a narrower engine size than that of the previous V6. The new heads decrease the engine package by 4.6 inches, making the unit easier to fit into the engine bay. With less surface area, the new design also slightly reduces noise at idle.

By Jake Lingeman