Headers: 4-2-1 or 4-1? Which brand/car?

[Ceil]

I drive a '90 Accord EX, with an F22A4 engine. I wanna do I/H/E, and already have plans for the I/E bit, but I don't know what to do about the headers.

Which is better - 4-2-1 or 4-1? Why?

What cars/engines have good headers that would fit my F22A4? Brother in law and I are goin' to a junkyard next weekend, and I wanna know what to look for.

Cheers.

[ExplodingCake]

You already have an 4-2-1 header set-up. You're good with it.

[Ceil]

So I take it 4-2-1 is better than 4-1? And that the stock F22A4 headers are as good as I can get without modifying stuff? I know the 'less than $500' thread tells you to use the A4 headers on your A1, but I was just wondering if there were better headers I could get for myself. Thanks for the info.

So why are 4-2-1 better? Just the way the air flows through the exhaust in that configuration?

[CB7lx91]

4-2-1 is better low end

4-1 is better top end

the f22a4 is the only stock "header" type design for our engines. The closest being the f22a6, which is a cast tubular manifold. A lot of guys on here swap out their f22a1 or f22a6 manifolds for the a4's design.

There seems to be a very little difference between a generic header (ebay brand) and the a4's design...only apperance.

On the other hand...if you pick up a nice Megan, DC Sports, etc. header, you will notice a difference

I forgot the issue, but Honda Tuning Magazine did a really good write up on the differences between 4-2-1 and 4-1. It was a couple months ago

[Accrdwgnguy]

I'd stick with the header you got.

[Ceil]

Is Honda Tuning magazine available online anywhere, or is it actually paper? :x

I know a few users on this forum are fans of Megan, and I've actually heard of DC Sports (which must mean something, given my limited knowledge), so maybe I should check them out. www.nopionline.com has a DC header for a few hundred, but it doesn't seem to be built for the EX model. Maybe they're selling an A4 clone

I think, from the multiple responses here, that I should hold on to my stock header. At least until I have the money to drop on a real performance piece (a la Megan or DC). Thanks o/

Edit: Think I found the article: http://www.hondatuningmagazine.com/t...est/index.html

[MadSpleen85]

Like already said, stick with what you have. You should be fine with it, unless you decide to do a full build. If you are going to seriously build your motor check out Bisi Engineering, on this site in the Member's Shops. You will pay more but you will get a header that is designed specifically for your application and has concrete R&D behind it.

[Ceil]

If it's between stock and full custom build, I think I'll just stay with stock, thanks Guess I/E will be enough for me. Save me some money, anyway

[johnl]

4-2-1 is better low end

4-1 is better top end

Not quite. A header with shorter primary pipes (the first pipes coming from the engine) will tend to give better power at higher rpm, a header with longer primary pipes will tend to give better power at lower rpm. This is all to do with the sonic pressure fluctuations that pass up and down the pipes, and are affected by pipe length(s).

But it's not that simple.

A 4-1 header will tend to give a strong (relatively) power spike at X rpm that exists over a fairly limited part of the rpm band (i.e. may contribute to a strong but narrow power band). A 4-2-1 will tend to produce a less strong power spike but one that is spread out over a wider rpm band, i.e. a more useable power band.

Typically (i.e. all else being equal) you might consider a 4-1 more suitable for track work where the header can be designed to work at the higher rpm you would typically be using when racing. A 4-2-1 might typically be considered more suitable for performance road or rally use than for racing, where a wider power band is more effective and pleasant(!) than outright power.

If using a 4-1 you'd also need to be sure that the tuned length of the primary pipes suited the set up of the rest of the engine, otherwise you might have say an engine that really wants to produce it's best power at say near/around 5,000rpm (cam timing, intake design etc), but the header might want to work best at say 7,000rpm. This would mean you wouldn't be getting good power from the engine as the header would be working against what the engine needs at the rpm that it needs it at. A 4-2-1 is likely to be much more forgiving in this respect than a 4-1 might be...

[CB7lx91]

^^ thanks man. I knew it wasn't as cut and dry as "this one is for this and this one is for that", but I didn't know 4-2-1's power range is so wide. That's probably why they are so common plasted all over ebay and such.

[SN2BH22CB7]

You already have an 4-2-1 header set-up. You're good with it.

X2 eggzackly..

why change the header and DP when you already have the best header/DP amongst the other F22Ax engines.

doesn't make any sense.

all you need is the A6 head/intake manifold...and PT6 ECU.

and you're good.

catco highflow cat ...catback exhaust...and CAI.

and you're good for around 150 - 155hp.

[SN2BH22CB7]

Not quite. A header with shorter primary pipes (the first pipes coming from the engine) will tend to give better power at higher rpm, a header with longer primary pipes will tend to give better power at lower rpm. This is all to do with the sonic pressure fluctuations that pass up and down the pipes, and are affected by pipe length(s).

But it's not that simple.

A 4-1 header will tend to give a strong (relatively) power spike at X rpm that exists over a fairly limited part of the rpm band (i.e. may contribute to a strong but narrow power band). A 4-2-1 will tend to produce a less strong power spike but one that is spread out over a wider rpm band, i.e. a more useable power band.

Typically (i.e. all else being equal) you might consider a 4-1 more suitable for track work where the header can be designed to work at the higher rpm you would typically be using when racing. A 4-2-1 might typically be considered more suitable for performance road or rally use than for racing, where a wider power band is more effective and pleasant(!) than outright power.

If using a 4-1 you'd also need to be sure that the tuned length of the primary pipes suited the set up of the rest of the engine, otherwise you might have say an engine that really wants to produce it's best power at say near/around 5,000rpm (cam timing, intake design etc), but the header might want to work best at say 7,000rpm. This would mean you wouldn't be getting good power from the engine as the header would be working against what the engine needs at the rpm that it needs it at. A 4-2-1 is likely to be much more forgiving in this respect than a 4-1 might be...

easily put...one word..


"BISIMOTO"

[deevergote]

easily put...one word..


"BISIMOTO"

Other than the Bisimoto header, there are no significant header upgrades for the F22A. You might gain a few horsepower from a DC Sports or Megan header, but it won't be enough to feel. The Bisimoto header is the only one that will give any significant gains. "significant gains" on a naturally aspirated Honda 4 cylinder are often fairly low themselves... 15-20hp from one bolt-on would be immensely impressive)


If you get an aftermarket header other than the Bisimoto header, do it more so for looks, or because your stock parts are rusting away.

[Grey_Fox]

Does anyone know how much does the Bisimoto header cost for the Accord?
400? 500?

[Ceil]

Does anyone know how much does the Bisimoto header cost for the Accord?
400? 500?

I checked a few places, but couldn't even find one. I was tired at the time, so didn't even bother to ask for a link.

But I'm awake now, so where can we get one?