What Does TQ Mean? It means three-Quarter, as in Three-Quarter Midget.

"Midget" race cars were first developed in the late 1930s, single-seat open-cockpit open-wheel machines of a size smaller than seen before. In the late 1940s, "midget-midget" cars began to appear, and soon they were dubbed "three-quarter midgets" due to their size.

It wasn't long before three-quarter was shortened to TQ.