These test pipes are direct replacements for the OEM catalytic converters on the Audi TTRS. They are constructed from 2.5" mandrel bent 304 stainless steel piping. Flanges are CNC waterjet cut from 304 stainless steel and TIG welded for perfect fitment. Piping is slightly reduced to fit OEM band clamps. Gaskets & hardware included.
Fitment is identical to OEM catalytic converters. Installation is simple. No permanent modification necessary.
TTRS test pipes deliver a sharper exhaust note and significant top-end horsepower gains. Some low-end torque is lost using test pipes, so we recommend these primarily for track days.