At Reno, they race seven classes of planes. Formula One: All the craft are powered by the same 10 hp Continental engine used in the Cessna 150, and can reach 250 mph. Sport Class: These are high-performance, kit-built aircraft with engines displacing 650 cubic inches or less, and reaching speeds of 350 mph. Super Sport: A more technologically-advanced variant of the sport class. T-6: This class features racing between the T-6 "Texan," the Canadian-built "Harvard," and the US Navy "SNJ." All the T-6 variants are powered by the Pratt & Whitney Wasp radial engine with 600 horsepower, and reach speeds of about 225mph. Jet: This class is open to any non-afterburning aircraft with less than 15 degrees of wing sweep. Biplane: In this group, small biplanes like the Pitts Special can hit speeds exceeding 200 mph. Unlimited: These are the Big Boys. The Unlimited Class is open to any piston-driven aircraft with an empty weight greater than 4500 pounds. The Unlimited Class is populated mostly by WWII fighters like the P-51 Mustang, F-8F Bearcat, and Hawker Sea Fury. Unlimited Class speeds reach 500 mph.