4-1 S.S Merge Collectors 2.25in Inlet ID 4in Me

The Vibrant Performance 4-1 S.S Merge Collectors 2.25in Inlet ID 4in Outlet is a purpose-built exhaust merge collector designed for enthusiasts seeking efficient primary tube consolidation and improved scavenging characteristics. This stainless steel component serves as the critical junction point where four individual primary tubes converge into a single outlet, making it an essential upgrade for naturally aspirated and forced-induction engine builds. Whether you're tuning a street machine, weekend track car, or high-performance street rod, this merge collector optimizes exhaust gas flow dynamics and supports increased power output.

Constructed from premium stainless steel with a natural finish, the 4-1 merge collector features 2.25-inch primary tube inlet diameter that tapers smoothly to a 4-inch outlet. The slip-on design eliminates the need for welding or complex fabrication, allowing straightforward bolt-on installation to most custom or OEM exhaust manifolds. The merge geometry is engineered to minimize turbulence and promote laminar flow as exhaust pulses converge, reducing backpressure while enhancing scavenging efficiency across the RPM band. Weighing just 3.55 pounds, this component adds minimal mass while delivering measurable improvements in volumetric efficiency and exhaust evacuation.

This merge collector is ideal for engine builders and performance enthusiasts upgrading from stock manifolds or fabricating custom exhaust systems on four-cylinder and six-cylinder engines. The 2.25-inch primary inlet accommodates standard header primary tube sizing, while the 4-inch outlet pairs seamlessly with mid-pipe and catback systems rated for that diameter. Installation typically requires basic hand tools and fits within a compact 6.6 x 6.4 x 12.1-inch envelope, making it compatible with most engine bay configurations. Expect noticeable gains in throttle response, peak power delivery, and exhaust note refinement when paired with a quality cat-back or full exhaust system.