Please! I just want to make sure I got this str8.

An engine works partly on how fast you can get oxygen in and how fast you can get it out. (i.e. the faster you get it in and get it out, the faster you go). Am I right in saying this?

And while we're on the subject, what role does a header have in this process? I understand that it plays a part in getting air out. So would it be safe to say that a 4-1 header helps to get it out faster? As opposed to a 4-2-1 header? I just wanna clear things up so I have a better understanding of things.

I've done a search!! And haven't found a fully detailed message on how a header works. So if anyone is willing to help please do so.

Thanks

Well as far as the headers go the 4-1 headers will give you more top end power and the 4-2-1 will give you more low end power. While on the subject for the 7th gen civic (as far as i know) they only make the shorty header for this car. Which means you can only buy one kind.

Ton of factors regarding oxygen intake and expelling (sp?) the resulting gases. How fast the engine can get some air, how much of it, the quality of it, tempreature...speed, acceleration, all that good stuff is partly determenied by this. There's so many factors though. How open the throttle is, amount of fuel being sent to the engine and mixed with the oxygen (air/fuel ratio!)....check out How Things Work...i think thats the right link...but they have a whole section on engines and how they do there thing.
As far as the header goes...I'm guessing that basically the quicker the exhaust gases can be relased, the sooner more air/fuel and be burned, thus somehow increasing power. I dunno...thats just a wild guess on my part, probably wrong. But with that logic the header that allowed for the smoothest air flow (that is large pipe diamter, no restritciotns) would be the best. I would think a 4-1 header would work the best, as it takes gases out of each cylinder and dumps it right away into a single exhaust pipe. I dunno, just a wild guess on my part.

<< Well as far as the headers go the 4-1 headers will give you more top end power and the 4-2-1 will give you more low end power. While on the subject for the 7th gen civic (as far as i know) they only make the shorty header for this car. Which means you can only buy one kind. >>



UM, HP makes the 4-1 header and a 4-2-1 as well if I am not mistaken. But anyway...thanks for your help guys. [IMG]i/expressions/face-icon-small-smile.gif[/IMG]

HP= lower end.

DC Sports= only makes one kind right now...higher end.

That's where the confusion is.


Cheers
tha BALLER

2cute is right, but do you know why a 4-1 header produces more top end power and a 4-2-1 header? It's this effect that happens as the exhaust gases travel out through the exhaust system. Each reduction or increase in pipe diameter produces shockwaves which go back up to the combustion chamber and actually help to expel exhaust gases and draw in fresh fuel and air. Now a 4-1 header only has one increase in piping diameter, so at a certain rpm the shockwave will be synchronized with the opening of the exhaust valves. A 4-2-1 header has two levels of increasing exhaust diameter. Each level is less pronounced, but you have two levels. You'll see gains at a lower rpm, and at a higher rpm. However, they will be less pronounced than the gains of the 4-2-1 header.

Manufacturers of headers call this shockwave tuning. At that magic rpm, the gains are pronounced. Up to 20% of the regular output of the engine at that rpm. Now imagine a system that varies the exhaust diameter dynamically! Dynamic shockwave tuning controller by the ECU based on the rpm's. Now that would be nice indeed. Have that 20% gain throughout the entire rpm range. Yummy.

wow grey - is dynamic exhaust tuning something real and just really expensive, or is it just an idea that just popped into your head?

And along with what Grey said, the exhaust gas is expelled in pulses. The whole point of having a tuned header is so that when each pulse of exhaust gas is expelled, the previous pulse is at the end of the header. Thereby creating higher velocity and then higher horsepower and torque.

Not bad AA!

peace

<< wow grey - is dynamic exhaust tuning something real and just really expensive, or is it just an idea that just popped into your head? >>



Just an idea I thought of. Varying the diameter of the exhaust dynamically would be hella hard though. I can't imagine a mechanical system capable of doing it. Well, I can. It wouldn't be simple though. To be viable it would have to be simple. Anyway, maybe some automobile manufacturer is working on something like that?