4-1 Merge Collector 1.625in Inlet ID 2.5in

The 4-1 Merge Collector 1.625in Inlet ID 2.5in by VIBRANT PERFORMANCE is a precision-engineered exhaust header component designed for serious engine builders and performance enthusiasts looking to optimize cylinder scavenging and flow characteristics. This merge collector serves as the critical transition point where four individual primary tubes converge into a single 2.5-inch outlet, making it essential for any custom exhaust system targeting improved horsepower and torque delivery.

At its core, the merge collector's effectiveness lies in its 1.625-inch inlet diameter specification, which is precisely calculated to manage exhaust gas velocity and pressure dynamics as four runners blend into one. The 2.5-inch outlet diameter ensures minimal backpressure while maximizing scavenging efficiency—the ability of exiting exhaust gases to draw fresh intake charge from adjacent cylinders during valve overlap. VIBRANT PERFORMANCE's design accounts for tube wall thickness, collector taper angle, and internal flow paths, all critical factors that separate dyno-proven components from generic alternatives. The compact 12.35-inch length allows flexible packaging in tight engine bay configurations without sacrificing performance gains.

This merge collector is ideal for naturally aspirated and forced-induction builds requiring custom primary tube integration, particularly in street performance, road racing, and engine swap applications where OEM exhaust manifolds are incompatible or restrictive. Weighing just 2.44 pounds, it's designed to pair with matching 1.625-inch primary tubes and feeds directly into a 2.5-inch secondary system. Installation requires proper TIG welding to primary tube bundles and outlet piping; confirm tube diameter compatibility and collector mounting flange specifications before purchase to ensure seamless integration into your complete exhaust architecture.