PONTIAC, Mich. (AP) - General Motors Co. says it's begun construction of a facility for race engine design and development in suburban Detroit. The Detroit-based automaker says the work started Wednesday on the site in Pontiac. The company says it also includes an electric motor laboratory and gear center. GM says its "continued investment in motorsports comes from the time-tested belief that racing is the ultimate proving ground for much of the technology" used in the vehicles it sells. The facility is called the GM Performance and Racing Center. Staffers will relocate from Wixom. Vice President Steve Kiefer says it will develop racing engines for Chevrolet and Cadillac vehicles. GM says about 100 people will work at the facility, which should open by mid-2015 and be completed by early 2016.