Due to emission regulations, Subaru has put restrictive catalytic converters in the exhaust system. These restrictive catalytic converters do not allow for optimal exhaust flow to the turbo, thus top performance of the exhaust system cannot be achieved. Also, removal of the catalytic converter helps prevent the possibility of damaging the turbo if the catalytic converter breaks apart.

GrimmSpeed’s Up-Pipe eliminates the restrictive catalytic converter and provides a larger diameter pipe that helps spool the turbo in a quick and efficient manner. There is a 10+ whp gain when using the Up-Pipe.Adding a non-cat'd up pipe is one of the first things you should do to your Subaru. Arguably one of the best $/HP ratios.

Another great feature of the GrimmSpeed up pipe is that the inlet is gasket matched so you have a perfectly smoothed out exhaust flow compared to the big step that that tiny stock inlet has.The GrimmSpeed Up-Pipe is specifically created without an EGT bung. An EGT sensor is not necessary. If you would like to keep tabs on EGT temperatures the correct place to do it is on the exhaust manifold right after the exhaust ports, this is the only place where the correct temperatures can be taken.

The entire Up-Pipe is made of 304 SS and has a pipe-wall thickness of 2.0mm. The inlet size is 1.92" and the outlet size is 1.72". The pipe tapers down to 1.72” and acts as a funnel as it moves into the turbo allowing for the smoothest transition and best air-flow quality. The flex joint is not located in the bend, which adds to the life expectancy of the flex section.

Our outlet size is a perfect match to the most common stock location turbos allowing for a smooth transition into the turbo.Since we are a porting company we make sure to have the smoothest transitions between pipes to allow for maximum flow and quickest spoolup (we call this "quality" airflow).