Perrin Radiator Shroud (Neon Yellow) - Subaru WRX / STI VA STI Engine This helps prevent unwanted manifold

This helps prevent unwanted manifold pulsations from affecting the FPR as the plenum is a common area of the manifold that represents the average vacuum/boost of all cylinders rather than a singular cylinder

ALL FA Turbo Subaru application

your factory bias is maintained as well as your ABS efficiency

Improves steering response

Perrin Radiator Shroud (Neon Yellow) - Subaru WRX / STI VA STI Engine This helps prevent unwanted manifoldWhy are radiator shrouds a good idea? Because they are designed to channel the air directly to the surface of the radiator to improve the cooling efficiency of your vehicle. This is a great solution for those of you who live in an area with a warmer climate, or it will help improve the cooling for high performance driving conditions such as a track day. If you don't have a radiator shroud, then typically air will still hit the surface of the radiator,