AJW Performance just recently acquired these new headers from Perrin to put on our RSTi build. These headers are a great addition to a Subaru! While you may lose some rumble the added horsepower is enough to bring the smile back to your face.
You can take a peek here to read Perrin’s blog post on why the Big Tube Header was created: http://blog.perrinperformance.com/bigtube-equal-length-header/
As for an official description and photos, well peek below.
The equal length design of the PERRIN header, produces smoother more balanced exhaust pulses flow from the head 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 mate with any aftermarket up-pipe that works with the OEM header.
You wont see grossly, way over sized tubing to make our header LOOK better. That just slows down exhaust gases and loses response. The PERRIN Big Tube header uses 1.625″ primary tubing that fits the Subaru exhaust port size. Our larger diameter header was designed for cars making 500+ wheel HP to not sacrifice low end power on cars with big aftermarket turbos installed.
PERRIN Flanges are CNC machined from 304 stainless steel and counterbored on the back side to make smoother transitions. Flange ports 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 causes gaskets to burn out quickly.
Most headers collect on the passenger side of the engine, and due to space constraints, are not equal length, compromising exhaust flow. Because we use the added room provided by the oil pan (only on 2.5L turbo pans), we can create a smooth transition of the header primaries to the collectors, and collectors to up-pipe, providing more power and torque than the competition.
Looking to purchase this part? Check it out in our store! HERE