Killer B Motorsport 4-1 Holy Header 2-Bolt Subaru WRX 2002-2014 / STI 2004-2021 | HH-2BOLT SkylineR34_1999-2002 All in all this Turbo

All in all this Turbo XS RBV BOV kit for the WRX and STi is the best we have seen from Turbo XS as far as Blow off valves is concerned and it may be the best BOV on the market today for your WRX or STi

BC 4340 billet steel crankshaft (79mm stroke)

The knob weighs in at a lightweight 113

Kits include a high quality

1 Thermostat Gasket

Killer B Motorsport 4-1 Holy Header 2-Bolt Subaru WRX 2002-2014 / STI 2004-2021 | HH-2BOLT SkylineR34_1999-2002 All in all this TurboPart #: HH 2BOLT The Killer B Motorsport Holy Header was developed using state of the art CAD software & simulations to determine optimal design to increase power in the mid to high RPM 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