Like so much under a vehicle's hood, throttle bodies are starting a switch to plastic. The part, critical in regulating the amount of air going to the engine, had been a mainstay of aluminum.
``It was basically the last bastion of metal around the engine's [air-intake system],'' said Robert Nelson, automotive components and materials director with GE Plastics' automotive headquarters in Southfield, Mich. ``But recent events are changing that.''
Italian auto supplier Magneti Marelli SpA of Bologna, Italy, and others had developed a plastic throttle body in Europe, said Donald Colliver, marketing manager for Magneti Marelli USA Inc. in Farmington Hills, Mich.
Now, the supplier has begun assembling the plastic part at its U.S. plant in Sanford, N.C.
The company, which recorded sales of about $4 billion last year, started work on its first North American throttle body in 1995.
``Aluminum was the conventional approach,'' said Colliver. ``But we had the go-ahead to try something new in plastic. We realized we could always revert back to Plan B and use aluminum if it didn't work.''
The throttle body, made with GE Plastics' Ultem polyetherimide resin, is used for the 2000 model year on DaimlerChrysler Corp.'s Dodge Neon coupe. Production on the Neon started in December.
The part saves about 10-20 percent of the cost of aluminum throttle bodies by consolidating parts, said Fred Fehr, Magneti Marelli throttle-body project manager.
The injection molded piece includes the shell and a molded-in throttle valve. The piece is attached to the chassis instead of to the engine itself.
Injection molder Fabrik Molded Plastics Co. of McHenry, Ill., molded the part for Magneti Marelli.
The Italian supplier eventually may add injection molding capabilities at its North Carolina plant, Colliver said.
The new throttle body could be just the beginning. Other suppliers, including Siemens Automotive LP of Auburn Hills, Mich., and Visteon Automotive Systems of Dearborn, Mich., also are looking into the technology.
GE has 14 potential projects for plastic throttle bodies in development, Nelson said.
The next stage, within about five years, could be an integrated plastic air-fuel module. The module, shipped to automakers as one piece, would include a plastic air-intake manifold, fuel rails, fuel injectors and the throttle body, Nelson said.
``That would dramatically drop the cost of using plastic,'' Nelson said. ``We're already talking to customers about it.''