Part #: HH4 - 1. The Killer B Motorsport Holy Header for Subaru WRX / STI is a game - changer. It's crafted using advanced CAD software and simulations to boost power in the mid - to - high RPM range. With super - short primaries and a single secondary, it cuts down header volume, enabling exhaust gas pressure to build rapidly. The symmetrical 4 - 1 design keeps exhaust velocity high and steady as RPMs climb, offering faster spool - up than long primary/double secondary designs. You'll instantly notice improved throttle response and more power at higher revs.
Features:
- Short Equal Length Primaries: Get the shortest possible primaries on an equal - length header for less volume and quick spool - up.
- Symmetrical Primary Design: All primaries have similar tube length and bend geometry, ensuring high and consistent pulse velocities.
- Smooth Mandrel Bends: Utilize mandrels for smooth, non - restrictive flow. We use the largest bends for top - notch performance.
- Thick - Walled 321 Stainless Steel: Ideal for high - temperature turbocharged applications. It's stronger and tougher than 304 stainless at high temps, preventing brittleness and cracking.
- High Heat Retention: 321 stainless conducts less heat. Short primaries and well - sized secondaries boost turbine efficiency.
- V - Band Up - Pipe Connection: Fast, easy, gasket - free, leak - free, and ensures perfect tube alignment.
- Up - Pipe Included: Designed as a complete system. Other up - pipes can compromise performance.
- Lightweight: Only 17 pounds compared to the OEM's 25 pounds.
- Compatibility: Works with OEM EJ25 Oil Pans and Killer B Motorsport Performance Aluminum Oil Pan.
- Quality Assurance: Made in the USA with Killer B quality.
- Wide Fitment: Fits all WRX & STi EJ Series Engines. Rotated setups can use it with an adapter.
Fitment:
- 2002 - 2014 WRX
- 2004 - 2017 STI
- 2005 - 2009 Legacy GT
- 2005 - 2009 Outback XT
- 2004 - 2013 Forester XT
Notes:
- 02 - 05 wrx may require 2.5l sti oil pan.
- 06 - 07 wrx needs sti oil cooler and sti oil pan.
- NOT LEGAL FOR SALE OR USE IN CALIFORNIA ON ANY EMISSION CONTROLLED MOTOR VEHICLE.
Using the Killer B Holy Headers is straightforward. First, make sure your vehicle is one of the models it fits (like 2002 - 2014 WRX, 2004 - 2017 STI etc.). If you have a 2002 - 2005 WRX, you might need a 2.5l STI oil pan, and a 2006 - 2007 WRX requires an STI oil cooler and oil pan. Install the headers as a complete system, including the included up - pipe. Don't try to use other up - pipes as it can affect performance. When it comes to maintenance, regularly check the V - band up - pipe connection for any signs of loosening. Since it's made of 321 stainless steel, it's quite durable, but avoid exposing it to extremely harsh chemicals. Also, remember that this product is not legal for sale or use in California on emission - controlled motor vehicles.
