EXPREME 4-2-1 Equal Length Exhaust Manifold for EJ255/EJ257

The Tomei EXPREME exhaust manifold is engineered as a 4-2-1 equal length header system to maximize the power potential of Subaru EJ255 and EJ257 engines. This design optimizes exhaust pressure, leading to significant peak power gains, particularly at high RPMs. The manifold features precisely sized pipes (φ42.7mm, φ45.0mm, and φ60.0mm) to ensure efficient extraction of power from the EJ25 turbine. Constructed from durable 2.5mm thick SUS304 stainless steel, this manifold is built for longevity. The collector utilizes the Lost Wax process, a method that eliminates weak points often found in welded areas and promotes smoother exhaust gas flow for improved efficiency. The equal length piping contributes to a unique, higher-pitched racing sound. This EXPREME exhaust manifold is compatible with a range of Subaru models, specifically the 2004-2021 Subaru STI and the 2006-2014 Subaru WRX. The package includes the exhaust manifold itself, a turbine support pipe, Titan exhaust wrap, and all necessary gaskets and hardware for installation. Key specifications include the 4-2-1 isometric design, 2.5mm pipe thickness, and pipe diameters of 42.7mm (main), 45.0mm (tip), and 60.0mm (support pipe tip).