The OEM midpipe is one of the biggest restrictions in the G37 exhaust system.  Infiniti figured this out when they redesigned the catback system for their Infiniti G37 in order to adapt a more free flowing system, which included a redesigned H-pipe with dual outlets as opposed the previous Y-pipe with a single outlet. With the revised exhaust system and a slight tweak to the ECU, the G37's gained 18 crank hp from the factory.

With the success of the Nismo exhaust on the Nismo 370Z, AAM Competition took performance one step further and designed the AAM Competition G37 Midpipe; a true 2.5" exhaust system. The factory Nismo H-pipe and intermediate pipe starts off at 2 1/8" behind the catalytic converters, opens up to 2 1/4" at the intermediate pipe, and then tapers back down to 2 1/8" by the time it reaches the muffler. Although we would never doubt Nismo components, we took on the challenge of designing a larger and more efficient system. The AAM Competition G37 Midpipe has been dyno proven to gain +20whp and +19tq over a stock G37. This makes it a perfect upgrade for those who want the added performance of an aftermarket midpipe but want to keep the factory muffler, or those who already have the AAM Competition Short Tail Exhaust and would like to continue modifying their OEM setup.