1971 IMSA GT Championship  The 1971 IMSA GT Series season was the inaugural season of the IMSA GT Championship auto racing series. It was for Grand Tourer-style racing cars which ran in the GTO and GTU classes, as well as former Trans Am Series cars in the TO and TU classes. It began April 18, 1971, and ended November 21, 1971, after six rounds. Overall winner in bold. Points are awarded to the top six in each class in the order of 9-6-4-3-2-1.