Porting and Polishing is the process of removing casting imperfections and reworking the part for optimized air-flow and velocity. There will always be a balance between air-flow and velocity. It is best to tell us your vehicles' modifications and goals in order to apply the right port profile for your specific application.

Porting and polishing reworks the parts so that they are gasket matched or port matched. In other instances we will leave an anti-reversion layer to keep a pressurized air wave from returning towards oncoming air. This will decrease performance.

Subaru Reversion Layer on Exhaust Ports


Other steps in the air stream must be ported or they will impede air-flow









A textured finish, or polishing, is done to promote a boundary layer. Similar to why a golf ball has dimples, a textured finish helps make the parts more aerodynamic for better flow and velocity. For exhaust ports a mirror finish is desired over a textured finish so that heat can be better retained for thermal efficiency.

IMG_20160105_141012841 (1)