Civic EG

between a 4-1 header and a 4-2-1 header???

Been beaten to death ... for our little engines there really won't be a noticeable difference. Just get a header.

i like 4-2-1 cause you can unbolt them in the center. well all the 4-2-1 ive own have..
and when doin work where i had to remove the header, it was ezier to remove the header from the down pipe.. but like said about there is no power diff, its just wat u perfer

^He makes a valid point. I hadn't considered that aspect of it. But as far as power the 4-1 will have a very slight shift in power band into the upper RPM range and the 4-2-1 will have a very slight shift in power to the mid/lower RPM range. But really the shift is so slight you will not notice.

That used to be the rule of thumb but it's just too broad a generalization and doesn't apply to current designs.

I knod of assume he's looking at a traditional equal length header, such as a DC or Edelbrock. I realize that when it comes to some of the newer designs such as Bisi's header this rule of thumb doesn't really apply as there is way more R&D and physics applied to the design of headers like that. But for the traditional equal length tubular header this principle still applies (to my knowledge) ... however, like I said with the d-series you really aren't going to notice ... so go with what you think looks best ... or is in your price range.

Search google for D series header comparison.

oscar jackson did testing decades ago with this on there d16 test engine, they said the 4to2to1 one peice header was the best all around from what i remember right, they recomended the "genie" brand... but like i said that was a long time ago, there may be better things out now, as that is a long period of time for R&D they also said the dc's were very high quality, wich everyone knows,

the big thing guys near me are using on a b seires are the Try-Y headers, they do great on bseries vtec engines... not sure if they make a header like that for a sohc, they may possibly...

personally 4to1 and Try-Y's have some ground clearence issues... on something i drive everyday, i like the 4to2to1 one peice, they seem to be a good happy medium

forcefedEG wrote:oscar jackson did testing decades ago with this on there d16 test engine, they said the 4to2to1 one peice header was the best all around from what i remember right, they recomended the "genie" brand... but like i said that was a long time ago, there may be better things out now, as that is a long period of time for R&D they also said the dc's were very high quality, wich everyone knows,

the big thing guys near me are using on a b seires are the Try-Y headers, they do great on bseries vtec engines... not sure if they make a header like that for a sohc, they may possibly...

personally 4to1 and Try-Y's have some ground clearence issues... on something i drive everyday, i like the 4to2to1 one peice, they seem to be a good happy medium

The 4-2-1 is a Tri-Y.

YY
Y See ... 4-2-1

AutoXCivic wrote:The 4-2-1 is a Tri-Y.

YY
Y See ... 4-2-1

http://inlinefour.com/blra4trhe.html <- true try Y

http://inlinefour.com/dccer1pc4in2.html <- 4to2to1 1pc

theres a major diff in the two granted the top one still says 4to2to1, but its a true try Y header, theres a huge design difference...

forcefedEG wrote:

AutoXCivic wrote:The 4-2-1 is a Tri-Y.

YY
Y See ... 4-2-1

http://inlinefour.com/blra4trhe.html <- true try Y

http://inlinefour.com/dccer1pc4in2.html <- 4to2to1 1pc

theres a major diff in the two granted the top one still says 4to2to1, but its a true try Y header, theres a huge design difference...

If you want to call the fact that the air goes into the 2 part further down stream major ... sure there's a "major" difference. But in the "true tri-y" picture you provided (not a very good illustration) it seems they join to far downstream to make a difference making that, essentially, a 4-1. I'm just going by how it looks mind you. In any case either way, if it starts in 4 tubes, then is redirected into 2 tubes, then joins together in 1 tube to finally be pushed out the exhaust ... I think that qualifies as a 4-2-1 header ... which makes three Y's. Just because is looks a little different doesn't mean it is fundamentally changed.

where the two merge together can change the power band charcteristics alot.... thats wat i was goin off of, the dc one is designed to give more torque.... because of the shorter primary tube lengths, changing the length, size and where the pipes merge can make a big diff. im not trying to argue im just saying....

but to answer the original question, i like the header somewhat like what the 2nd link in had went to for a sohc... http://inlinefour.com/dccer1pc4in2.html

I'm not trying to get into a pissing contest here either, I know next to nothing as far as the R&D that goes into designing a good header. I was "just saying" as well. In any case, to OP, unless you are doing a full race (not streetable at all) N/A build ... it really isn't going to make a difference, and anything is better than the stock exhaust manifold. My e-bay special header has held up fine for 2 years (plus a couple of years on the car of the guy I bought it from) it made and immediate noticeable difference in power, and it was cheap.

AutoXCivic wrote:unless you are doing a full race (not streetable at all) N/A build ... it really isn't going to make a difference, and anything is better than the stock exhaust manifold. My e-bay special header has held up fine for 2 years (plus a couple of years on the car of the guy I bought it from) it made and immediate noticeable difference in power, and it was cheap.

x2 i got a ebay header on my dd and not had a problem outa it...

i want these.. =]