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Hi guys,

Just about all manifolds have the exhaust primaries merge at the turbine flange.

Has anyone ever done a 6-2 then into the flange? Is there any reason not to do this? Anything else that I may be missing?

Thought this maybe cleaner/easier to package than wrapping 6 primaries into 1 area. I've seen it done for other cars before but not on our cars.

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You are just adding complexity and taking up space.

I don't know what you mean by taking up space?

3x1.5 will take up more space than 1x2.5?

EDIT: Not sure what you mean by complexity either, it's 1 pipe crossing over the engine mount vs 3 wrapped around. It's also just 2 pipes joining at the flange instead of 6. If you do it right, you can swap between a T6/T4/T3 easily.

Edited by s2d4

Mainly Space savings so easier to fit something like a GTX47, better packaging and placement of wastegates, less welds, can swap setup easily etc.

Check out Burns Stainless, they do some pretty fancy merge slip on turbo collectors.

From personal experience if going from Trust 6-2-1 manifold and gate to a 6boost 6-1 manifold and Turbosmart gate....on a lil 2L where exhaust energy is at a premium the 6-2-1 design worked better than 6-1 design. Better power and response...same tuner, same dyno, same wheels and similar dump pipe

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It really depends on your goal but I prefer smaller diameter runners, 6-2-1 with less merge area to keep the gas speed up. This may restrict your top end capabilities a little, but most don't need 800+kw of flow anyway.

Don't forget, the wastegate path is just as important as the turbo, the incorrect angle off the merge may see you struggling to control boost without a 60mm gate, and perhaps limit your top end flow unnecessarily.

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