Headers 4-2-1 or 4-1

[bgsteve523]

I am getting my esu back from hondata at the end of the week I just wanted to know if 4-2-1 or 4-1 headers would be a good set up with hondata. I am looking to buy some as soon as I gewt some feedback. Trying to figure out the difference between the two.
Thanks,
Steve O

[bgsteve523]

ohh and one more quick thing does a high flow cat really help or is it a waist

[Lucid Moments]

It depends on what you want to do. 4-1 headers will give you higher peak #'s, but with most of the power at high revs. A 4-2-1 will give lower peak #'s, but with better gains at lower revs. If you race your car a lot the 4-1 header might be better for you, and if you spend most of your time on the streets you might like a 4-2-1 better. By the way, if you race your car a lot you might want to look at the JR Race header. It replaces the cat so you are probably not street legal, but it will give the highest gains of any header I am aware of.

[bgsteve523]

so basicly 4-1 power in high revs and 4-2-1 power in lower revs. So with hondata 4-1 is prob better right?

[Lucid Moments]

Originally posted by bgsteve523
so basicly 4-1 power in high revs and 4-2-1 power in lower revs. So with hondata 4-1 is prob better right?
Right

[kenis138]

I have 4-2-1 and hondata setup and i like it, although ive never tried the hondata without the header, looking forward to your results.

[trk]

is the dc 4-2-1 or 4-1?

[Lucid Moments]

Originally posted by trk
is the dc 4-2-1 or 4-1?

DC Headers are 4-2-1

[bgsteve523]

I am going to prob go ahead and get RD 4-1 headers I figured with the extra rev's of hondata it should be a great set up.
Thanks for your help guys.

[chunky]

Originally posted by mlkelley68
It depends on what you want to do. 4-1 headers will give you higher peak #'s, but with most of the power at high revs. A 4-2-1 will give lower peak #'s, but with better gains at lower revs. If you race your car a lot the 4-1 header might be better for you, and if you spend most of your time on the streets you might like a 4-2-1 better. By the way, if you race your car a lot you might want to look at the JR Race header. It replaces the cat so you are probably not street legal, but it will give the highest gains of any header I am aware of.

that's only half the story.

a 4-1 header will not always lose midrange power and a 4-2-1 header will not always compromise peak power.

Each header is designed for a certain powerband. It's up to the maker of the header to decide that - the fact that it is 4-2-1 or 4-1 doesn't have a whole lot of impact on powerband location. What is important is the length of the primaries - that is what determines in large part where the powerband is located. Long primaries will shift the powerband higher, short ones will make power lower in the rpm range. But the length of the secondaries can also have an impact on power production at a seperate rpm range. And then there are various anti-reversion construction techniques incorporated headers that help power production at all rpm.

Also, the JR race header is definitely not the only longtube solution for the ep3. there's the comptech race header, the hytech race header, and of course the toda race header. All of those are longtube headers and provide significant gains in power production everywhere in the rpm range.

the best compromise header is the borla header, which has longer primaries than all of the shorty headers, but still retains the stock cat.

[Lucid Moments]

I bow to Chunky's superior knowledge

[myeverlovinsir]

Well said chunky. I certainly did not have any compromise up top using the DC 4-2-1 design and got one of the best tq outputs NA for the A3.;)

[bgsteve523]

WOW awesome info thank you! About the racing headers I would love to get one but my real question is if I am getting rid of my cat is the power that much better? AND will a local shop do the install knowing it will no longer be officaly street legal?
Thanks,
Steve O

[chunky]

Originally posted by bgsteve523
WOW awesome info thank you! About the racing headers I would love to get one but my real question is if I am getting rid of my cat is the power that much better? AND will a local shop do the install knowing it will no longer be officaly street legal?
Thanks,
Steve O

ridding yourself of the cat will make more power. most shops here in GA won't do the install.

racing headers are expensive, around a grand, except for the JR header which is about 600-700.

[bgsteve523]

cool thanks for the info what about a high flow cat would that help