60 years on, the Porsche 911 continues to be one of the best sports cars on the market. Porsche is keeping the 60th-anniversary celebration rolling with the 911 S/T, a stripped-down 911 aimed squarely at the purist 911 fan. The naturally-aspirated 4.0-liter, 517-horsepower flat-six is mated to a six-speed manual transmission with a lightweight flywheel...