A now-defunct motorsports series under IMSA. Founded in 1969 and folded in 1999, the GT Championship was the original form of IMSA's main sports car racing league. The series was succeeded by the American Le Mans Series, which itself is the predecessor of the current IMSA SportsCar Championship
Several Japanese platforms are notable for their success in this league, including the FB RX-7 and Z32 300ZX.
