Killer B Motorsport 4-1 Holy Header 2-Bolt w/EGT Bung - 2002-2014 Subaru WRX / 2004-2021 STI / 2004-2013 Forester XT

The 4-1 Holy Header has an EGT bung to improve the performance on the Subaru STI.

Killer B Motorsport 4-1 Holy Header 2-Bolt w/EGT Bung

---

Specs:

• Cast Collector: The collector is made of thick-walled cast 347 stainless. This design removes several welds which removes flow disruption for less turbulence. This also allows the collector to be designed as a true high-velocity merge.
• Short Equal Length Primaries: Shorter length primaries make for an equal length header which means less header volume and quick spool up
• Symmetrical Primary Design: A similar tube length and bend geometry keep the pulse velocities high and consistent when compared to equal length headers with different non-symmetrical primary tubing geometry.
• Smooth Mandrel Bends: All the bends utilize a mandrel to promote non-restrictive flow, and Killer B uses the largest bends possible at every location
• Thick-Walled 321 Stainless Steel Construction for Long Life: 321 is alloyed with titanium which not only costs more but it is ideal to handle the elements of extreme heat found in the turbocharger - With that being said, the turbocharger will create heat that will surpass the limits of 304 stainless steel, and 321 is more robust to promote longer life

Killer B Motorsport 4-1 Holy Header

Killer B Motorsport designed the Holy Header to provide the exhaust gases with an uninterrupted flow to the turbocharger to improve the horsepower and the torque, while greatly improving the throttle response. This is an equal-length design and will come with an EGT bung welded onto the piping for those of you who need to pay attention to those parameters.

It has also been designed with the 2-bolt up-pipe flange for those of you who will employ the stock up-pipe or any aftermarket up-pipe with the stock-like flange.