A Fox Body Mustang running twin 102mm turbochargers and a FuelTech FT500 engine management system laid down a 3.91 at low elapsed time in the eighth mile – on a tire narrow enough to look undersized for the power on tap. Driver Josh Klugger backed up the pass in qualifying, no small feat with this much boost on tap. Here’s what it actually takes to make a small block Mustang run numbers like that.