3-1 Merge Collector ID 1.625in Inlet/2.5in Out

The 3-1 Merge Collector ID 1.625in Inlet/2.5in Out from VIBRANT PERFORMANCE is a precision exhaust manifold component engineered for builders who demand efficient cylinder scavenging and reliable flow characteristics. This merge collector serves as the critical junction point where three primary pipes converge into a single outlet, making it essential for naturally aspirated and forced-induction engine builds that require optimized exhaust gas velocity and reduced backpressure. Whether you're fabricating a custom street engine, track car, or performance swap, this header collector provides the foundation for a cohesive exhaust system that maximizes horsepower and torque across the RPM band.

VIBRANT PERFORMANCE engineered this collector with a 1.625-inch inlet diameter per primary runner and a 2.5-inch outlet diameter, a sizing ratio that promotes smooth gas transition and minimizes turbulence at the merge point. The stepped design prevents dead zones and exhaust reversion, maintaining consistent scavenging efficiency even during rapid throttle transitions. Constructed from heavy-duty mandrel-bent tubing, the collector is designed to handle sustained high-temperature cycles without warping or cracking, with precision welding throughout to ensure durability in extreme conditions. This geometry works in concert with header tube sizing to create backpressure sweet spots that improve low-end torque while sustaining mid and top-end power.

Fabricators and engine builders benefit most from this merge collector when constructing custom headers for applications where OEM manifold geometry no longer applies—LS swaps, engine transplants, and purpose-built race engines all depend on properly sized collectors. The 1.625-inch primary inlet accommodates standard header tube sizing (typically 1.5 to 1.625 inches), while the 2.5-inch outlet provides a professional transition to downstream exhaust piping, high-flow cats, or mufflers. Installation requires proper welding and alignment to your specific primary tube configuration; verify tube diameter and merge angles during header design to ensure optimal fitment and performance. At 2.025 lbs, this component integrates seamlessly into lightweight exhaust systems without adding excess weight.