Subaru Impreza WRX STI 1st Gen car poster.
In 1994, Subaru introduced Subaru Tecnica International (STI) versions of the WRX in Japan. These models were upgraded from the standard WRX in many categories, including blueprinted performance-tuned engines, transmissions, and suspensions. The STI versions of the WRX were immensely successful in rallies and popular among street racers but were only sold in the Japanese market. Compared to the WRX, the STI had mostly mechanical modifications.