GrimmSpeed Unequal Length Header 2002-2014 WRX/ 2004-2021 STI

DESCRIPTION GrimmSpeed believes that there has not been any major changes to the unequal exhaust manifold in some time, and this is due to the tight geometry and long cross-pipe between the two collectors. Although it provides the Subaru with that signature boxer sound, it is not optimized for flow or power. This design is great for low-end spool, but the factory exhaust manifold runs out of steam higher in the rev range. To relieve this issue, other manufacturers would design a more equal-length header with larger diameter runners to make up for the performance. Because of these reasons, GrimmSpeed has created a header that would offer the best of both worlds meaning excellent power delivery throughout the entire RPM range, while still delivering that flagship boxer rumble. WHY? This header was designed to deliver consistent power through the gears while providing that Subie rumble everyone loves. Get more power and better sound with the GrimmSpeed Unequal Length Header. FEATURES: Substantial Power/Torque Gains Quickest Spooling Aftermarket Header No Tune Required Gaskets and Hardware Included Designed To Fit With Aftermarket Oil Pans - Full 304 Stainless Steel Construction Manufactured and Welded In The USA COMPATIBILITY 2002-2014 WRX 2004-2021 STI