Rebored Throttle Bodies
Subaru's TM presented
under Fair Use
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 STi
Subaru Legacy GT