what's up
right now I'm looking into buying a header but I seen two different types, one is 4-1 and the other one is 4-2-1 but I'm not sure which one is better, please help
thank you

which headers are you loking at specifically?

I used to say, "don't bother at all with headers" but now I am changing my mind. While they don't tend to give much (if any) peak hp gains, they do add some power low in the rpm range which isn't a bad thing. If you are concerned with just drag racing then I'd say don't bother, but a header should make your car drive better on the street.

I'm not trying to contradict you Todd, but I had always heard to opposite about headers... that you gain some top end power but might lose some low end. The interesting thing is I don't think I lost any low end power when I put mine on. I got the Greddy 4-1 header, yes I know lots of money, but I really like it. Acceleration is smoother. Overall it just made the car more driveable if that makes sense. As far as power goes, I noticed little or no low end loss, mid to upper rpms I noticed a fair gain, but its hard to tell exactly because it makes the car respond differently. One piece of advice I will give is I would not get a header with that slip fit connection. I would get one with actually flanges that bolt together. If you have any more questions feel free to ask.

Sorry about the length all!

most people say 4-2-1 is best but i wont have mine for a few weeks, i dont even know which one i have ordered cause it is coming as a kit.

hey i got a greedy header too and i felt a little difference not much but if u go to http://www.importtuner.com/tech/0202it_ppeclipse/ youll find the report the have on upgrading and eclipse rs it shows that a header does not give u much hp but gives u more torque. Also there was a post here in performance forums that talked about the difference between 4-1 and 4-2-1 and i cant remember when it was posted so look it up. I remember that it said that 4-1 will give u more power in the top end (when your already going fast) and that 4-2-1 will help u more while taking off, but i could not tell u because when i bought my header i was not aware that there was a 4-2-1 for our cars until i found this website, wich was much much later.
hope it helps

Actually, I have got to agree wth Todd. The high RPM difference is not noticable, but the real gain is around 3000-3500RPM. That is where Todd is most noticibly quicker then me. His car has a lot more punch at 3000-3500RPM then mine does. The best that he can figure by looking at dyno charts, is that the header makes the power come on a little bit sooner. It shows on the charts, and it seems to show on the street.
-=B-=

>Actually, I have got to agree wth Todd. The high RPM
>difference is not noticable, but the real gain is around
>3000-3500RPM. That is where Todd is most noticibly quicker
>then me. His car has a lot more punch at 3000-3500RPM then
>mine does. The best that he can figure by looking at dyno
>charts, is that the header makes the power come on a little
>bit sooner. It shows on the charts, and it seems to show on
>the street.
>-=B-=

I agree with you, all the header really does is shift the powerband down a little to lower rpms. I was really confused when I got mine because that is exactly what I saw, but was a little apprehensive about posting that because of what is "believed" to be true about headers and their gain. Thank you for clearing this up, I feel better about posting this now.

Well, I don't think that it shifts the power down, that would imply a loss of power at high RPMs. I think that it just adds some power in the mid-RPM range. 3000-3500 range seems the best range for gains.
-=B-=

...You want the headers that will provide the most power and they are the 4-1 Headers. Forget whatever you've read. The 4-1's are it. With your engine and it's breathing abilities the 4-1 is the one to have with less restrictions which the 4-2-1 has. Going straight from the 4-1 will aid in high HP while the 4-2-1 help in midrange TQ. You want HP though if you want speed. Midrange TQ isn't used when racing at high rpms. What good is TQ but once at 4K when accelerating if you can't use it at 5-7K on the 1st though 3rd gears you'll be using it at when racing. On the other hand if you want to feel the power when doing low rpm city driving then you may consider the midrange TQ.

Personally I have the 4-1 and want the high rpm HP for ultimate speed and acceleration at more gears.

thanks for the help

staying auto, 4-1 or 4-2-1???

...but the since the powerband isn't really utilized you need torque to get up to speed so I would say 4-2-1