Well after 3+yrs of learning, tonight a local riceboy has me thinking....
 

Im ashamed ;), bwhahah.......about headers. Yes, boring old headers. It happened when I was at work.

Riceboy: Yo man hey did i tell you whats Im doing to my ride now!? (drives gsr)
Me: No what?
Riceboy: Im getting me a header y0. What should I get?
Me: Well I had a DC 4-1 a while ago that was cheap and appeared to give me a couple midrange and top end ponies.
Riceboy: Well see I wants to go autocrossing y0 so don't I need a 4-2-1?
Me: Well I don't know, I used to regard the 4-2-1 as your everyday header really, better for superchargers perhaps. (Was thinking the kamikaze was 4-2-1, then got home and realized its an awkward 4-1 that has extremely short primaries.)
Riceboy: Well the guy on my message board said that if I wanted low end power I had to get a 4-2-1, that a 4-1 only benfits high end and would suck at autocross y0.
Me: Well I don't know honestly, its been a while since i concerned myself with headers and their minimal differances and gains. Go online tonight and see if you can find more opinions.


Sooooo, ive been tinkering around with it tonight and keep getting the same old thing over and over listed on sites. "4-2-1 is great for low end, 4-1 is good for high" Now if you go by this the riceboy is right in theory, then again if you autox correctly you should be on the cam 80% of the time really. So then I read some ---- by the infamous TOO over at endyn, he seems to think 4-1 headers are good but that dc sucks compared to any triy design. heheh.

If you read reviews for headers on review sites for 4-1, you get a lot of "noticeable power increase from vtec up!" If its for 4-2-1 you get lots of "noticeable power increase from vtec up!" So whats up with this ----, somebody needs to shed some good light on the subject of what header desing is good for these NA b series motors. We know kamikaze rules all for boost which is a demented 4-1 with hella short primaries, so just na please. Give me some good detail and reasonign too please, dont be short. Ive had enough of reading one liner sentences describing why to choose one desing over the other thank you...

Oh im so embarrassed to ask.......no not really.

Re:Well after 3+yrs of learning, tonight a local riceboy has me thinking....
 

???Are you trying to see which is better? ???

This forum needs spell check badly....

Re:Well after 3+yrs of learning, tonight a local riceboy has me thinking....
 

4 to 2 to 1's are good for low end. the straight 4-1 design was really meant for the high compression top end cars. for autocross and stability. perfect example the jdm type R.

i hate headers as because of their hp to dollar ratios however in autocross you dont really need turbo.
me on the other hand i would skip all that and get a sohc greddy kit, hks manifold bolt that on and have all the low and top end i need with 6psi.

he would see way better results.

but were talking headers.

my best header would definatly be the kamikaze. perfect design short runners for better exhaust flow.

after that, the jg edelbrock and skunk2 however there in the 550 range.

but by far the best with a worked motor is that spoon header. such a nice and cripsy header tuned perfect. but it only makes numbers with alot of spoon cars, wonder why lol.

hope that helps

Re:Well after 3+yrs of learning, tonight a local riceboy has me thinking....
 

You have done a lot of research from the looks of it. There is quite a lot involved in the proper selection of headers. You mentioned a couple, purpose of car: autocross, road coarse, daily driver, drag race etc. Then it is a good idea to consider the rpm range the engine will operate in based on the gear ratios. Does it have an LS tranny where you will drop rpms way more than in a close ratio Y1/YS1 type tranny. You should graph these out to see the rpm at shift, and draw a line at vtec to show if you drop below or not. Hyper Rev magazine does a nice job of this.

Overall the 4-1 header will give higher peak performance gains, and may come at a loss of power in the low end. The 4-2-1 is the best all around header and will make power at most all rpm ranges, just will lose its efficiency at the top and and won't make as much as the 4-1.

If you are really into the subject, read "The scientific design of intake and exhaust systems", it is a great book and will tech the bejesus out of you, but you will walk away with a lot more confidence in making decisions on what you want.

Jim

Re:Well after 3+yrs of learning, tonight a local riceboy has me thinking....
 

The dc jdm 4-1 made 5 hp over jdm type-r. Then i know this place who made headers have 20 hp over dc jdm 4-1.

Re:Well after 3+yrs of learning, tonight a local riceboy has me thinking....
 

Whats up wit may spellign? hehe, was in a hurry when typing sorry. Anyways, some good replies. Oh and that book on the science of exhaust and intake systems seems like it would be a good read.

Ok, so because theres a time period during the stroke of our combustion engines when both the exhaust and intake valves are open at the same time, this is the main factor in designing a header correct. So if this is why backpressure is important for NA cars (of course for turbo backpress. is the devil, and gets in the way of currently exiting mass gas, and then probably makes the motor work harder then it should completing the stroke whereas it could have concentrated that energy to the transaxle.....ok now im rambling) anyways.....so does a 4-2-1 make more backpressure down low by being more restrictive? What is it about those back pulses of exhaust that help the intake valves draw more air in when both are open at the same time?

Thanks for responding.

Re:Well after 3+yrs of learning, tonight a local riceboy has me thinking....
 

This is off topic, but he would be the first riceboy I've ever seen that wants to autocross. :o

Re:Well after 3+yrs of learning, tonight a local riceboy has me thinking....
 

hes not that bad, just kinda annoying....anyways somebody respond to my last post about the back p issue, or ill come to believe nobody knows.

Re:Well after 3+yrs of learning, tonight a local riceboy has me thinking....
 

Oh come on guys, its been 3 days, somebody answer the question. Yes, I have searched online....I cant find the answer.