4-1 Merge Collectors

The 4-1 merge collector is the classic way to join four header primaries into one outlet, and this collection covers the Vibrant Performance T304 stainless 4-1 merge collectors in common inlet and outlet sizes.

What a merge does

Instead of dumping four primaries into a plain cone, a merge collector brings them together at a shallow angle around a center merge. Exhaust pulses leave one tube and help pull the next cylinder clean, which builds power, especially in the upper RPM range.

Where 4-1s are used

Each bank of a V8 header, an inline four header, and four-runner turbo manifolds feeding a single turbine inlet all commonly use a 4-1 merge.

Sizing

Match the inlet to the primary tube O.D. and the outlet to the collector extension or turbo inlet. The listing gives inlet, outlet and length.

Common questions

4-1 or 2-1? A 4-1 favors peak power. A tri-Y with 2-1 merges favors midrange torque.

Is T304 enough for a turbo manifold? For most builds, yes. Consider T321 for extreme heat.

How do I keep the primaries even? Tack all four evenly around the collector before finish welding.

What's in This Collection

  • 18 products from Vibrant Performance, priced from $259.99 to $299.99
  • Materials: 304 Stainless
  • Free shipping on orders over $150

How to Choose

Match the tube outside diameter and material to the rest of your build. 304 stainless is the most common choice for exhaust, 321 stainless handles the extreme heat of turbo manifolds and headers, titanium saves weight, and aluminum is the go-to for intake and intercooler piping. Wall thickness and bend radius matter when you need parts to fit together cleanly.

More Questions

Do I need to back purge stainless when welding?

Yes. Back purging with argon keeps the inside of the weld from sugaring, which gives you a stronger, cleaner joint.

Can I mix stainless and mild steel?

You can weld them together with the right filler, but the joint can rust over time. For best results keep the system one material.

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