The Impreza S202 STI version, which was based on the competition model of the Impreza WRX STI series (type RA spec C), was the result of thorough improvements in on-road performance by STI. In an effort to further increase the output of the EJ20 Boxer Turbo, STI revised the intake system and developed a titanium sport muffler with single chamber/piping, which achieved ultra low backpressure. A weight reduction of 5.4 kg was also made possible. The output characteristics of the special sport ECU were modified for specifications that emphasised an increased output at high revolution ranges, and allowed a maximum output of 235 kW (320PS) compared to 206 kW (280PS) in the base car. The rear suspension included pillow ball bush lateral and trailing links for linear and sharp rear suspension actuation. As a result of STI’s commitment to weight reduction in the unsprung mass, forged aluminium wheels and brake discs featuring alumite treatment and slits were fitted. The wing-type rear spoiler with a two-step angle adjustment system was made of real carbon. The S202 achieved an extraordinary power-to-weight ratio of 4.15 kg/PS and a high dimension of balance.