Slip-On Merge Collector 2in-3-1/2in

The HEDMAN Slip-On Merge Collector 2in-3-1/2in (Part #29109) is a weld-on exhaust collector designed to consolidate multiple primary tubes into a single outlet for custom exhaust system builds. This slip-on merge collector accepts four 2-inch primary tubes and transitions them into a 3.5-inch outlet, making it essential for performance exhaust applications where header consolidation is required before the downpipe or cat-back system.

Constructed from natural steel, the collector measures 12.875 inches in length and weighs 4.1 lbs, providing structural integrity for high-temperature exhaust gas flow. The slip-on design allows for precise alignment and fit during welding, reducing fabrication time compared to traditional bolt-together designs. The 2-inch to 3.5-inch transition ratio is engineered to manage scavenging efficiency while minimizing backpressure, a critical consideration in custom engine builds where header tube diameter and collector design directly influence exhaust scouring and volumetric efficiency.

This collector suits fabricators and engine builders working on street rods, race applications, engine swaps, and performance modifications where OEM exhaust manifolds are replaced with tuned primary tube systems. The natural steel finish requires protective coating or paint to prevent corrosion; most builders apply ceramic coating or high-temperature exhaust paint for longevity and heat management. The 6.3 x 6.3-inch face dimensions provide mounting compatibility with standard four-tube primary configurations.

HEDMAN exhaust components are recognized in the performance automotive community for precision engineering and weldability. When selecting a merge collector, tube diameter matching and outlet sizing are critical to system tuning—undersized outlets create restriction, while oversized outlets reduce scavenging. This 2in-3-1/2in ratio is a proven transition for mid-range engine applications and is compatible with standard 3.5-inch downpipes and cat-back systems.