Subaru supplies its turbo owners with a tiny little crosspipe from the factory. 50% of your exhaust gasses are passing through this tiny pipe and, well, that's just a problem. The GrimmSpeed HiFlow Crosspipe is made of 304 SS(flanges, flex, tubing) and has a pipe-wall thickness of 14 Gauge, this is the most "heavy-duty" pipe you will find. Many other pipes use cheap thin steel and are marketed as "super light weight", not us. The one of a kind Triple Layer Flex Joint is not located in the bend, which adds to the life expectancy of the flex section. This unit is built from 1.92" 304 Stainless Steel tubing, maximizing exhaust flow from cylinders 1 and 4 to the manifold collector for faster turbo response. Customers have seen up to 15 HP INCREASE when combined with our PnP Subaru Exhaust Manifold. The pipe by itself should net around 5-8 HP INCREASE. Add on our amazing Ceramic Heat Coating for a VERY SMALL fee to help keep the heat in and speed up those exhaust gasses even more. *Features* * Boost transition is improved over stock * Helps airflow in the mid to high rpm range.