180 degree header

[jeff115]

not sure if this would go in engine tech or turbo?
I have a few sets of flanges, and am getting ready to make a few exhaust manifolds. have you guys seen any 180 degree headers? pairing 1,6-2,5-3,4 into an open exhaust housing? helps with low/mid on a gasser. Would it help spool a turbo better? I'll bet it would look cool any way.

 

[Leiffi]

not sure if this would go in engine tech or turbo?
I have a few sets of flanges, and am getting ready to make a few exhaust manifolds. have you guys seen any 180 degree headers? pairing 1,6-2,5-3,4 into an open exhaust housing? helps with low/mid on a gasser. Would it help spool a turbo better?

Turbos want as short manifold as possible and 6 cylinder engine wants divided exhaust housing 123 and 456.

 

[zfaylor]

Turbos want as short manifold as possible and 6 cylinder engine wants divided exhaust housing 123 and 456.

Don't discredited the OP too quickly. Do you understand the premise of 180 degree headers? They aren't like a normal header at all.

 

[Leiffi]

Don't discredited the OP too quickly. Do you understand the premise of 180 degree headers? They aren't like a normal header at all.

If firing order is 153624 then there is no better manifold than 123 + 456, none of the cylinders overlap each other and pulses are just perfect.

 

[zfaylor]

If firing order is 153624 then there is no better manifold than 123 + 456, none of the cylinders overlap each other and pulses are just perfect.

:Cheer:

Wasn't accusing you of not knowing your chit. Just making sure everyone is on the same page since most people have not heard about 180* headers.

 

[RyanMayo]

not sure if this would go in engine tech or turbo?
I have a few sets of flanges, and am getting ready to make a few exhaust manifolds. have you guys seen any 180 degree headers? pairing 1,6-2,5-3,4 into an open exhaust housing? helps with low/mid on a gasser. Would it help spool a turbo better? I'll bet it would look cool any way.

Well, you wouldn't have a 180 degree header there, since cylinders 1 and 6 are 360 degrees separated, as are 2-5 and 3-4. And then when they join up at the open housing you'd have a 120 degree header. I guess you could call the typical divided manifold, (as Leiffi described,) a 240 degree design.

Semantics aside, I can tell you from experience that an open, .88 a/r turbine housing spooled significantly worse on a friends truck than a divided .91 housing, no other changes. I think for this reason your proposed design would show performance loss. If however, your header design was used with a "triple scroll" turbine housing, there may be some benefit. JMO

 

[COMP461]

like these , I beleive that longer primarys will help get past the first and second order of resonance, and aid spool up

here in my V 8 merge headers