Confused with 4-1 & 4-2-1 headers


pateras_vtec

pateras_vtec

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Feb 16, 2008
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Right, i`m confused about the way these two kinds of manifolds work, and in which power band they are more effective.

I read and read but can`t seem to get a solid answer on weather a 4-2-1 header is used to improve mid-to-high revs and a 4-1 low-to-mid revs or vice versa. In best motoring "Type R Legend", there`s a part where they mark face and preface-lift differences for the integra R. They say that (as we all know) that a SS header (4-1) is equipped to the face-lift teg, which makes more torque in lower revs. Honda specifically announced at the time 18.5kg`s @ 7500 preface and 19.0kg`s @ 6200 face-lift.

Since the the facelift teg made more torque down low, keeping the same power (200hp@8K) isn`t it safe to assume that a 4-1 header performs better in the low-mid region of the engine whilst a 4-2-1 in the mid-high?
 
I always thought it was 4-1 is better high end power. That is what I have noticed with my B16B.
 
Yep, 4-1 will give best results at top end. 4-2-1 will improve power throughout the rev range especially midrange power but won't be as good top end as 4-1. Clearance can be a big issue with the 4-1 if car is lowered due to how low the downpipes to collector sit.
 
pateras_vtec said:
Right, i`m confused about the way these two kinds of manifolds work, and in which power band they are more effective.

I read and read but can`t seem to get a solid answer on weather a 4-2-1 header is used to improve mid-to-high revs and a 4-1 low-to-mid revs or vice versa. In best motoring "Type R Legend", there`s a part where they mark face and preface-lift differences for the integra R. They say that (as we all know) that a SS header (4-1) is equipped to the face-lift teg, which makes more torque in lower revs. Honda specifically announced at the time 18.5kg`s @ 7500 preface and 19.0kg`s @ 6200 face-lift.

Since the the facelift teg made more torque down low, keeping the same power (200hp@8K) isn`t it safe to assume that a 4-1 header performs better in the low-mid region of the engine whilst a 4-2-1 in the mid-high?
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======== Header FAQ ======== - HondaCivicForum.com
 
Vtec6000 said:
Yep, 4-1 will give best results at top end. 4-2-1 will improve power throughout the rev range especially midrange power but won't be as good top end as 4-1. Clearance can be a big issue with the 4-1 if car is lowered due to how low the downpipes to collector sit.
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On what experience is this statement based on? Have you dyno`d both kinds on your car maybe? It would be very interesting to have such a comparison. Still if a 4-1 delivers at top end, how could be explained the `98 teg`s performance?


cool link Szabb1 but that doesn`t clarify anything.
 
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98 specs performance is different due to the gearing mostly witht he revised final drive and ratios in the S80 box mostly.........

4-1 is more free flowing with less back pressure, easy to see with the design

Instead of collecting into groups of 2, the pipes stay as 1 for longer then join to 1 all in 1 go

performce wise consider it the same as comparing a conventionally routed exhaust to a straight through under fuel tank exhaust like the RSR or amuse R1 titan. under fuel tank will give free-er flowing revs compared to a conventional routed exhaust

Hope that makes sense..........
 
I wouldn't pay to much attention to it.

Design, lengths, configurations, pipe/bore sizes. etc etc bla bla bla. Basically every header is different. Mugen 4-1 virsus Mugen 4-2-1 may give this common perseption of 4-1 more top end and 4-2-1 through out rev range. But then compare say a Toda 4-2-1 to a mugen 4-1 the result may be completely different.

IMO toss a coin heads 4-1 and tails 4-2-1 and pick a brand!
 
i'd always say go for a 4-2-1 for clearance so you can run a front tie bar or H-brace

h-brace tightened up mine a heap!

friend removed the h=brace from his hillclimb integra and showed me the deformation about the mounting points, shows just how much flex there is in the subframe as standard even though the type R ones are reinforced :shocked:
 
stevenEK9 said:
i'd always say go for a 4-2-1 for clearance so you can run a front tie bar or H-brace

h-brace tightened up mine a heap!

friend removed the h=brace from his hillclimb integra and showed me the deformation about the mounting points, shows just how much flex there is in the subframe as standard even though the type R ones are reinforced :shocked:
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Agree with that! :nice:
 
Wonder how mine will sit with d2 coilovers,mugen 4-1 and an h-brace. Me thinks i am bolloxed!!!
 
martin251184 said:
Wonder how mine will sit with d2 coilovers,mugen 4-1 and an h-brace. Me thinks i am bolloxed!!!
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Have you got a brace mate? I bought a cheap ali one from flea bay to check clearance.... Smashed the siht out of it, had to throw it in the skip. Mine sat very close to my 4-2-1.

My car is quite low though. :angry:
 
yes, 4-1 headers have serious ground clearance problems. But i don`t think that it`s just a random pick. otherwise makers wouldn`t go through all the trouble making them.
 
my car sits low, H brace has about 60mm of clearance, not smashed it on anything!! does drag on the snow at the moment though

Saying that, my suspension has very little travel, haha
 
stevenEK9 said:
my car sits low, H brace has about 60mm of clearance, not smashed it on anything!! does drag on the snow at the moment though

Saying that, my suspension has very little travel, haha
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I am sure i will be fine.Only planning on dropping the ride height a bit anyway.
 
Im about to fit a 98 spec dc2 header, and my car is quite low on coilovers. I'll stick a few pics up once fitted next week.
 
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The best header out at the min is the new skunk 2.Its a 4-2-1 but gives strong power through out the power range
I have a 4-1 and my car is lowerd about 50-60mm and clearance is not a prob
 
Boyle said:
The best header out at the min is the new skunk 2.Its a 4-2-1 but gives strong power through out the power range
I have a 4-1 and my car is lowerd about 50-60mm and clearance is not a prob
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there is no best header, there is no best part, it's like saying 1 woman is the prettiest girl in the world, it's just not possible, i'm sure it's a great header but there simply isn't such a thing as "best header".
 
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