well really in truely it all depends on what you want to do with your engine. yes 4-1 is great and so is 4-2-1 for differnt reasons.

 

I personally like the 4-2-1 style header for a daily driven street car. it seems to offer the smoothest powerband lower in the range. 4-1 header designs vary alot however if you examine the way the exhaust gases move out of the cylinder head you would definetly agree that with a long tube header like the 4-1 style on hondas will produced a powerband later in the RPM range. hey, before I turboed my integra, I ran a 4-1 and thought it was great, but from stop light to stop light is what mattered for me. I swapped for a 4-2-1 and was very pleased.

in the end, you have to make the car work for you when you mod it. make sure the modifications you're making are going to best suit your needs.

thumbs up for easy install of a 4-2-1 style header...

 

I actually only stubled across it a few days ago when I was searching for info about something totally unrelated. Haven't seen any dyno charts.
There is no "best" for any one particular situation.

Are you just doing bolt ons, or are you doing internal mods?

Are you keeping your bolt on exhaust, or are you planning on getting a custom 2.5" setup?

 

For the money, you cannot beat the JDM ITR manifold. They go for around 400-500 bucks. While some other companies might offer marginal increases (Hytech, Comptech, JUN, TODA, etc...) their manifolds are generally more expensive. I was looking for the old website that had a bunch of comparisons of all sorts of headers (It was a tech article on B-series.net, or a similar site.. not a forum thread), but couldn't find it. To summarize what it said, for all it's worth, the JDM ITR manifold is the best buy for the money, hands down, if you're going to go 2.5". The other manifolds offered one-two, and one case (I believe it was the $1000 Hytech 4-5hp at peak) increases over the ITR. If you're not in california or another emissions controlled state, you can pair it with a 2.5" Type 1 Racing cat, B-pipe, axleback exhaust and (which is my current setup) and it bolts all together with no fuss (except for the extra o2 sensor hole that has to be tapped).
All told, I bought the header, cat, b-pipe and axle back for less than a grand, and saw a noticeable difference.

 

I plan on going allmotor and i know it sounds different i want to to be still a lil quiet so i can drive it on the street. Yes i plan on a full head package and going to a 84 mm bore. i want something like a 2liter integra with mad internals done, thats about it. any suggestions would help. Ohh and for my setup i dont have a cat(testpipe).

 

If you're going all-motor at some point in the future then I suggest holding off on a header upgrade for now. You will not see much of a gain from a 2.5" header on a stock motor and you will need to modify your current exhaust setup somewhat for it to work.

Once you get on to this "monster" setup of yours you will benefit from a full 2.5" exhaust system from the collector on back.

 

I am runnin the JDM 4-1, and I love it....on my stock motor it wasnt much of an increase, but the header combined with HF cat and 2.5 all the way back def. let it breathe better, and I can feel it a tad bit on the high end...I would imagine if I built the block and head a bit more that it would really start to shine.