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Perrin E4-Series Equal Length Big-Tube Header 04+ STI / 06-14 WRX
Perrin E4-Series Equal Length Big-Tube Header 04+ STI / 06-14 WRX
Perrin E4-Series Equal Length Big-Tube Header 04+ STI / 06-14 WRX

Perrin E4-Series Equal Length Big-Tube Header 04+ STI / 06-14 WRX

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The equal length design of the PERRIN E4-Series Header produces smooth, balanced exhaust flow from the heads to the turbocharger giving you the best of two worlds: quicker turbo response as well as more horsepower and torque throughout the entire RPM band. While designed to fit to the factory up-pipe, our header will also mate with an aftermarket up-pipe that fits factory header and turbo, as well as any rotated turbo kits compatible with the factory header. This header uses 1.625" primary tubing that is expanded at the flange to fit the Subaru exhaust port size. This size tubing is perfectly designed for cars making more than 500WHP.

PERRIN Flanges are CNC machined from 304 stainless steel and counterbored on the back side to make smoother transitions. Flange ports are sized properly to ensure exhaust coming out of the head has a smooth, unobstructed path to the tubes. The ports are not over-ported which would cause gaskets to burn out quickly. The tubes are expanded inside the flanges for a perfect fit and smooth flow of exhaust gases to the tubes

Due to its equal length design, the PERRIN header will alter the tone of your exhaust. The exhaust pulses from the engine are equalized and spread out producing a smoother, more refined sound. A byproduct of the equalization is a significant reduction in the volume of your exhaust sound. Some describe the sound as being similar to an inline four cylinder engine exhaust


  • 304 Stainless Steel Construction
  • Equal Length Design
  • 1.625in Primary Tubing
  • CNC Machined Flanges
  • Brushed Stainless Steel Finish
  • Header Gaskets Available (Optional)


  • Better Exhaust Flow
  • Increase in HP and Torque
  • Low-Profile Design

Please Note:

  • '02-'05 WRX Requires oil pan with header cutout and oil pickup tube, as well as modifications to radiator.
  • '06-'07 WRX Requires 2002-04 WRX oil cooler assembly and oil feed pipe
  • '04-'08 Forester XT Requires oil pan with header cutout, oil pickup tube, 2002-04 WRX oil cooler assembly, and 2002-04 WRX oil feed pipe
  • WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to