In your Subaru engine there are a set of butterfly valves in your intake track, what these do is open and semi-close to speed up airflow to the engine during low-rpm and low load situations, to help with combustion, but if you are looking for power gains, the stock TGV have restrictions.
GNP's TGV Deletes are an easy and cost-effective way to eliminate restrictions in your 2015+ WRX and 2014-2018 Forester XT intake tract!
Our Tumble Generator Valve (TGV) Deletes removes the restrictive butterfly valves from the intake tract to allow for a higher volume of airflow for more power and sharper throttle response.
The GNP TGV's are compatible with the factory O-ring sealed manifold, so no gaskets are required.
A retune is required to take full advantage of the TGV deletes.
2015 - 2020 wrx
2014 - 2018 forester xt