AMS Performance Catless Race Down PipesUnsurpassed Performance, Durability and Sound The Alpha Nissan GT R 90mm Cast Widemouth Downpipes are the best performing and most durable on the market. During testing our shop GT R with Alpha upgraded turbos saw gains across the power band of 100 wheel horsepower and over 130 ft lbs of torque with this simple bolt on! Turbo spool up was also improved by almost 400rpm! Unparalleled Durability and Performance through Proper Engineering Our downpipes