Tomei Exhaust Manifold Kit Expreme Unequal Length Subaru WRX 2015-2021 WRXUnequal length runners on the headers achieve the unique boxer engine rumble. The OEM headers restrict air flow resulting in loss of power and efficiency. Tomei headers do not restrict air flow resulting in an increase in power and efficiency. The OEM headers greatly restrict air flow right after the engine port. Unlike the OEM headers, Tomei headers do not restrict air flow right after the engine port. The turbo side of the OEM headers severely