On this episode of Head 2 Head, Jonny Lieberman pits the new 2013 Nissan GT-R Black Edition against its twin-turbo, all-wheel-drive rival, the 2012 Porsche 911 Turbo S. With 500+ horsepower planted firmly to the ground, both supercars annihilate California's canyon roads, then square off for an epic quarter-mile drag race.