Part Number: HH-DIY

Description: Equal Length 4-1 Holy Header; w/ DIY Up-Pipe

Fitment: 15-21 Subaru STI 2.5L

Not for sale or street use in CA & CARB states.

Details:

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.