Exhaust Manifold Design

[s2d4]

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.

[KiwiRS4T]

A number of fabricators make nice 6 into 1

You are just adding complexity and taking up space.

Usually at this point I post up a pic of my Sinco masterpiece but I'll refrain...

[Hadouken]

Do it

[s2d4]

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 February 23, 2016 by s2d4

[s2d4]

Do it

Sure, tossing up some CNC billets at the moment.

Just doing as much research as I can.

[Piggaz]

What are you hoping to gain/achieve?

[s2d4]

What are you hoping to gain/achieve?

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

[bigmikespec]

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.

[s2d4]

Edited February 24, 2016 by s2d4

[Ben C34]

They look expensive

[Roy]

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

[Dobz]

An old trust manifold I used to have with 6-2-1 design. Don't know if it about performance advantage but it looks good.

[niZmO_Man]

Is that a low mount? Trust? Looks like a Nissan copy to me

[s2d4]

Interesting examples, never knew they existed.

[s2d4]

Would love some manifold fabricators/vendors to chime in.

[scotty nm35]

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.

[niZmO_Man]

Interesting examples, never knew they existed.

Some bloke name Fred Gibson ran a HR31 Skyline during the Group A era. He made his own manifold.

You can also ask R31House for one.

[GH05T]

would that be for twin vane gear?

edit, twin scroll.

Edited February 25, 2016 by GH05T

[Ben C34]

I wouldn't trust a guy who can't plumb an air flow meter correctly

[Piggaz]

I wouldn't trust a guy who can't plumb an air flow meter correctly

On the strut tower you reckon, lol.