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Killer B Equal Length 4-1 Performance Holy Header W-Uppipe - Fits Subaru WRX 2002-2014 - STI 2004-2019 - More

Killer B Equal Length 4-1 Performance Holy Header W-Uppipe - Fits Subaru WRX 2002-2014 - STI 2004-2019 - More

Regular price $1,669.00 USD
Regular price Sale price $1,669.00 USD
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The Killer B Motorsport Holy Header was developed using state of the art CAD software & simulations to determine the optimal design to increase power as much as possible throughout the rev range. Primaries were made as short as possible along with a single secondary which significantly decrease header volume allowing exhaust gas pressure to build quickly.

Not CARB Legal

The symmetrical 4-1 design maintains high and consistent exhaust velocity as RPMs rise. You can expect significantly faster spool up time compared to long primary/double secondary designs. You will immediately notice an improvement in throttle/boost response and the ability to hold more power higher into the revs.

Cast Collector

  • The collector is thick-walled cast 321 stainless steel. The casting removes several welds, each weld removed is one less flow disruption (reduced turbulence). The casting has features milled into it that assure the primary tubes fit VERY concentric every time. Using a casting allows the collector to be designed as a true high velocity merge rather than tubing that can only be formed a little bit, and not ideally. The casting is thicker/stronger than formed tube and also holds heat better.

Short Equal Length Primaries

  • The Holy Header includes the shortest possible primaries you can have on an equal length header. Short means less header volume and quicker spool up.
Symmetrical Primary Design
  • All Holy Header primaries have a similar tube length AND bend geometry. This keeps the pulse velocities high and consistent compared to equal length headers with 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 and costs more, but it’s the ideal material for high temperature turbocharged applications. The temperatures on turbocharged cars can easily exceed the limits of 304 stainless steel enough to make them brittle and crack. 321 stainless steel has higher strength and toughness at high temperatures. It was developed by the aircraft industry specifically to address cracking issues in 304 stainless manifolds. Killer B Motorsport is the only company that manufactures full 321 headers.

High Heat Retention

  • 321 stainless steel conducts far less heat than 304 stainless steel. The short primaries and properly sized secondaries also pull less heat from the exhaust gases, increasing turbine efficiency. Large tubing headers expose the exhaust gases 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.

V-Band Up-Pipe Connection

  • Why V-Band? Fast, easy, no gasket, no leaks, and perfect 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.

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.

Made in the USA!

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