The Subaru throttle bodies can be rebored 2mm oversize from stock. The butterfly is replaced by a new machined component that precisely match the new bore size. The inlet is also enlarged with a new machined taper. The throttle shaft is modified to improve airflow as well, by complete removal of the front half of the shaft on the leading face of the throttle plate.

Subaru STi: Rebored 62mm/Stock 60mm, Inlet machined from 66mm to 68mm.

Proflow Design Throttle body on the Subaru Rally Car at the X-Games

Subaru WRX
Price $175.00

Subaru WRX STi
Price $250.00

Subaru Legacy GT
Price $175.00