The Manhart TR 850 is based on the previous-gen 991.2 Porsche Turbo 911 S. Based in Wuppertal, Germany, Manhart Performance used to be the realm of fast BMWs, but not anymore. Manhart's latest creation takes the standard 3.6-liter six-cylinder engine of the 911 Turbo S and heads to the stratosphere. The standard engine receives a healthy power boost courtesy of …