4-2-1 Tri-Y Header for K20Z3

The K-Tuned Civic Si header is a performance-oriented exhaust component designed for the K20Z3 engine. Featuring a 4-2-1 Tri-Y configuration, this header aims to improve exhaust flow and engine output. It is constructed from durable 409 Series Steel and includes CNC-cut 3/8 inch thick flanges for a precise fit. The outlet measures 2.5 inches, allowing for increased exhaust gas velocity and scavenging. This header is specifically engineered for the 2006-2011 Honda Civic Si models. Fitment past the subframe and sway bar is noted as perfect, with ample clearance for engine movement. The design utilizes 44mm primaries that smoothly transition into larger piping, contributing to its performance characteristics.