The Borla XR-1 Single-Tip Catback Exhaust for the WRX and STI features 3in piping with Borla's patented XR-1 multi-core muffer for optimal flow. This system does not use a resonator like the Hush, so it has a deep, powerful tone. The section of the catback that bolts to the downpipe is slip-fit, and can be replaced with the 3in adapter for future upgradability.The downpipe section Borla includes will bolt perfectly to your stock downpipe, but the optional 3in adapter simply bolts on and removes the bottle neck if you plan to use a 3in downpipe. Backed by Borla's million mile warranty, and constructed of stainless steel -- this is a great performing catback for your WRX or STi.
Part Number: 140075
Note: Are you using a stock j pipe or downpipe? If yes, the GrimmSpeed Subaru Stock DP to Aftermarket 3 in. Catback Adapter p/n 077046, is required.