The 2014 Chevrolet Corvette comes with the Stingray nameplate, a sleek new design, and a healthy 460 hp V-8 engine. For some, however, this all-American sports car leaves something to be desired in the performance department: The outgoing 2013 Corvette ZR1 still holds the title of “most powerful Corvette ever produced,” with its 638 hp V-8 engine. For those looking to outdo last year’s ZR1, Callaway Cars and Hennessey Performance each have an answer. 
Callaway Cars (not to be mistaken for the golf brand …