The TurboXS downpipe uses a full 4" cast bell mouth section on the turbo side, tapering to a 3" mandrel-bent stainless pipe.
The downpipe is sold with a TurboXS high-flow cat to connect up to your TurboXS cat-back exhaust.
We've had a few people inquire about just buying the front half of this downpipe, as a "shorty" downpipe to fit their factory cat section. That's not going to work; the front half of this downpipe is designed to fit the full 3" TurboXS cat pipe ONLY.
Fits all 2008-2014 WRX and STI. Also fits manual-transmission Legacy GT/Outback XT 2005-2009, and Forester XT 2009-2011.