Killer B Motorsport 321 Stainless Steel Holy Header With DIY Up-Pipe

The Killer B Motorsport Holy Header was developed using state of the art CAD software & simulations to determine optimal design to increase power as much as possible throughout the rev range. Short as possible primaries with a single secondary significantly decrease header volume allowing exhaust gas pressure to build quickly. Symmetrical 4-1 design maintains high and consistent exhaust velocity as RPMs rise. You can expect faster spool up time compared to long primary/double secondary designs. A difference you will immediately notice in throttle/boost response and the ability to hold more power higher into the revs.

2004-2018 STi, 2002-2014 WRX, 2004-2013 Forester XT, 2004-2009 Outback XT, 2004-2009 Legacy GT (Forester, outback and legacy models need to verify oil cooler clearances.)