4-1 S.S Merge Collector (1-7/8in Inlet ID 2.5in

The 4-1 S.S Merge Collector from Vibrant Performance is a premium stainless steel exhaust manifold designed for builders seeking to consolidate four individual cylinder runners into a single merged primary tube. This collector is ideal for street, strip, and track applications, bridging the gap between high-revving performance engines and efficient exhaust scavenging.

Constructed from mandrel-bent 304 stainless steel tubing, the 4-1 design features a 1-7/8-inch inlet diameter for each of the four runners, promoting exhaust gas velocity and scavenging efficiency at mid to high RPM ranges. The merge collector consolidates these four pipes into a 2.5-inch outlet diameter, optimizing pipe diameter transition to reduce turbulence and backpressure while supporting direct bolt-on or custom piping configurations.

Weighing just 3.2 pounds, this compact design (12.1 inches in length) fits tightly in modern engine bay constraints without sacrificing strength or flow capacity. The 4-1 S.S Merge Collector is particularly beneficial for those upgrading a carbureted or fuel-injected 4-cylinder engine platform or fabricating a custom build, ensuring durability under sustained heat cycles that would compromise mild steel alternatives.