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- 2002-2005 WRX
- 2006-2007 WRX
- 2008-2014 WRX
- 2004-2007 STi
- 2008-2014 STi
- 2015-2019 STi
- Brand: KillerB Motorsport LLC
- Manufacturer's Part Number: HH-EWG
- Primary Material: 321 Stainless Steel
- Manufacturer's Warranty: Lifetime warranty against manufacturing defects
- We ship internationally! Please email us for international shipping quotes.
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.
Short Equal Length Primaries. The shortest possible length primaries you can have on an Equal Length header. Short means less header volume and quick spool up.
Symmetrical Primary Design. All primaries have a similar tube length AND bend geometry. This keeps the pulse velocities high and consistent compared to equal length headers with different (non-symmetrical) primary tubing geometry.
Smooth Mandrel Bends. All of the bends utilize a mandrel for smooth non-restrictive flow. Not only that, we use the largest bends possible at every location. It would be cheaper to use 2" bends everywhere, like others do, but that's not going to give the best performance.
Thick Walled 321 Stainless Steel Construction for Long Life. 321 is alloyed with titanium, costs more, a lot more, but it's the ideal material for high temperature turbocharged applications. Would 304 stainless work, yes, but the temperatures on our turbocharged cars can exceed the limits of 304 stainless enough to make them brittle and crack. 321 stainless steel has higher strength and toughness at elevated temperatures. It was developed by the aircraft industry specifically to address 304 stainless manifolds that were cracking. Killer B Motorsport is the only company that manufactures full 321 headers.
High Heat Retention. 321 stainless steel conducts less heat than 304 stainless steel. The short primaries and properly sized secondaries also pull less heat from the exhaust gasses increasing turbine efficiency.
Provides More Precise Metering of Boost for Faster Spool and Responsiveness
Improved Power Due to reduced IWG/Turbine Turbulence
Up-Pipe 'Stub' Machined from Solid 321 Stainless Bar for a Perfect Fit and Thick Wall Reliability
V-Band Connections (no gaskets needed)
Includes Vent-to-Atmosphere Dump Tube
Designed for Maximum Flow using a 38mm Wastegate
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