AAM Competition 3” High Flow Cat Downpipes for the GT-R. This is an essential upgrade to optimize your GT-R’s exhaust system and power. Turbocharged vehicles gain power from getting as much exhaust gas out as quickly as possible. The AAM Competition 3” High Flow Cat Downpipes allow the turbo to spool faster, harder and with more efficiency, giving you more power. With less resistance heat is evacuated faster, so you will also benefit from lower engine temperatures. The result is a noticeable power gain across the entire rpm range as well as the ability to support additional peak power. The 3” High Flow Cat Downpipes are produced from highly durable 16-gauge T-304 stainless steel here in our US facility, which completely eliminates the need for additional support brackets.