IAG V3 Black Top Feed TGV Housings with Butterfly Pass Thru

The OEM Subaru intake manifold features “Tumble Generator Housings,” which are designed to decrease cold start emissions by “tumbling” the airflow on cold starts. Once the cold start process is over, the butterfly valves in the housings remain in the open position and don’t restrict flow much. This means that there are airflow gains to be had, even with the butterfly valves in place. We’ve completely redesigned our popular TGV housings with new port shapes to further improve airflow and allow for the OEM emissions equipment compatibility. We’ve seen gains of 5 WHP over our V2 TGV housings, and 13 WHP over stock housings.