Lighter Than Aluminum for Powertrain App

Although aluminum seems to be the material of choice when it comes to lightweighting powertrains, the BMW 5 Series Gran Turismo 550i and 750i use a transmission cross beam made of fiber-glass reinforced polyamide.

Although aluminum seems to be the material of choice when it comes to lightweighting powertrains, the BMW 5 Series Gran Turismo 550i and 750i use a transmission cross beam made of fiber-glass reinforced polyamide. Plastic. Engineering plastic. But plastic. In a structural application. The component, produced for BMW by ContiTech Vibration Control, is said to be 50% lighter in the application than an aluminum component.

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The injection-molded crossbeam links the engine-transmission with the chassis. In addition to providing strength—realize that the 550i has a 360-hp 4.8-liter V8 (the car, equipped with a six-speed manual, can go 0 to 60 mph in 5.4 seconds), so the issue of capability is certainly non-trivial--other concerns that were addressed during the development included acoustics and crashworthiness.

 

 

 

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While there are an increasing number of tubes, connectors, pans, and other plastic components used in powertrain applications, this serious structure points to even more opportunities for alternative materials.