3-1 Merge Collector 1.75 in Inlet ID/2.5in Outlet

The 3-1 Merge Collector 1.75 in Inlet ID/2.5 in Outlet by VIBRANT PERFORMANCE is a high-flow exhaust header merge collector designed for engine builders and performance enthusiasts seeking efficient multi-runner consolidation. This component bridges the critical transition between individual exhaust runners and a single exhaust outlet, serving as the foundation for optimized scavenging and back-pressure management on carbureted, naturally aspirated, and turbocharged builds. Whether you're assembling a street rod, weekend racer, or restoration project, a quality merge collector directly impacts horsepower delivery, throttle response, and overall engine efficiency.

Engineered with precision-welded 16-gauge mandrel construction, the 3-1 merge collector features 1.75-inch inlet diameter runners that taper to a 2.5-inch outlet, creating smooth flow transitions that minimize turbulence and separation. The stepped design allows each runner to maintain velocity while converging energy, reducing waste heat and resonance—critical for maximizing exhaust scavenging across RPM ranges. VIBRANT PERFORMANCE's proven manufacturing process ensures consistent internal geometry and durability, with robust welds rated for extended high-heat operation and vibration resistance across repeated thermal cycles.

This merge collector fits small-block and mid-size engine platforms with standard three-runner header configurations and is ideal for custom intake manifold systems, supercharger setups, and turbocharged applications. Installation requires basic welding or flange-bolt mounting to engine-specific headers; verify inlet runner sizing and outlet flange compatibility with your header manufacturer before purchase. At 2.05 lbs and compact dimensions (6.7 x 6.3 x 12.2 in), it integrates easily into tight engine bays while delivering measurable gains in mid-range torque and peak power output when paired with a properly tuned exhaust system.