NOTE: 2.0L WRX engines will need the 2.5L STI oil pan install kit.
The PERRIN Big Tube Header is perfect for those of you looking to increase both horsepower and torque numbers. However because this header features 1.625” tubing, this makes for the perfect header for those employing a rotated setup looking to make more than 500 horsepower.
The E4 Series Big Tube Header comes with collectors that have been designed to further improve exhaust flow throughout the runners in an equal fashion. This results in improved power, but additionally the new E4 series has been designed to have a lower profile for ground clearance.
Users will also enjoy the benefits of the equal length design with balanced flow from the heads straight to the turbocharger. This results in quicker turbo response compared to the OEM manifold and improved response throughout the entire RPM range.
Plus one of the better benefits is the weight savings. The OEM manifold is constructed from a heavy, cast material that is burley, and restrictive. The PERRIN unit because of the materials is substantially lighter, and with enough patience it can be a one-person installation.