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Killer B Motorsport Holy Header

Killer B MotorsportLLC


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.


Features include:


· 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. Large tubing headers expose the exhaust gasses to more surface area transmitting more heat and reducing exhaust energy. You can also ceramic coat or wrap our headers (and keep the warranty) without exceeding the temperature range like you can with 304 stainless.


· V-Band Up-Pipe Connection. Why V-Band? Fast, easy, no gasket, no leaks, perfectly concentric alignment of tubes for no disruption of flow, what’s not to like!


· Up-Pipe included. Of course it comes with an Up-Pipe! This header was designed as a complete system. Using other up-pipes would only compromise performance, and nobody wants that.


· Weights only 16 pounds (vs. OEM weights 25 pounds)


· Works with OEM EJ25 Oil Pans, and Killer B Motorsport Performance Aluminum Oil Pan!


· Fits All WRX & STi EJ Series Engines. Designed to work with OEM location turbo. See below for ‘DIY rotated setup.


· Available with External WasteGate Option


· Made in the USA!

Killer B Motorsport WRX / STi HOLY HEADER - Patent Pending


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Killer B Motorsport Design and Manufactures Aftermarket Performance Subaru Impreze WRX and STI parts

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Killer B Motorsport Header Review by YimiSport

+40wtq gains

+27whp peak gains

· More power EVERYWHERE!

What can be expected from Killer B Holy Headers?


·  Improved throttle and Boost Response


·  Customers report +25wtq and +25whp on average


·  More Consistent EGTs across all cylinders


·  More Power Higher into the Rev range


·  Improved Fuel Efficiency


·  Perfect fit! (some WRX models may requite OEM Oil Cooler to be rotated)


External WasteGate

· 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


DIY Rotated

· Includes Non-Trimmed or Welded 321 Stainless Steel Up-Pipe

· No Turbo Flange Provided

· Up-Pipe to Manifold V-Band Included (not welded)

· No Accommodations for External Waste Gate Included

· Allows placement of Up-Pipe to Accommodate nearly any Rotated Turbocharger setup

· DIY Reduced cost!

EXTRAS / SPARES: V-Band Clamps, Gaskets, Studs and more

Traditional Internal Waste Gate (see External Waste Gate Option Below)

External Waste Gate


Extras / Spares





· Works with any 2-Bolt Up-Pipe, including rotated

· Two-Bolt Reduced cost!

· Up-Pipe not included