Headers, No Power?

[deevergote]

Prelude header. Accord exhaust. However, look for 2.5" piping for the exhaust. You'll need the extra breathing capability for the H22!

[CBL]

Kamikaze are good headers for a cheep price and you will make horse power. Sorry I didnt know you had an h22a, thats a diffrent beast. I think Bisimoto has a header out for the h22a i would check it out.


I know bisimoto has a f22a prototye for sale for like 700 bucks. I want to see that in an accord

[alex]

i know this is the noob forum, but for gods sake we only have ONE header.

Thank you for saying it!!!

[DC4KiD]

A header is only part of the puzzle. If you only install an aftermarket highflowing header, and not upgrade the rest of your exhaust, then you're not getting the most of it. Just like a few posts up ahead 'it all adds up in the end'.

[Skunk138cb7]

Its HEADER theres only one

[deevergote]

Its HEADER theres only one

You're a day late my friend... that's been said already.

[757cb7kid]

please dont increse exhaust without upgrading the cat .... its like pinching the tube in your penis while you pee

[Mike]

F22's probably do react better to header mods, but how bout the H22?

acctully the f22a6 and i think the a4 are both very good manis. they react just the same or even worse than than the h22 manifold

[deevergote]

please dont increse exhaust without upgrading the cat .... its like pinching the tube in your penis while you pee

True, a free flowing cat of the proper size is always good. Carsound makes good ones. DO NOT just hollow out your stock catalytic converter. It pollutes the air, and it does nothing but create backpressure inducing turbulance in the exhaust flow. You need your exhaust to flow smoothly and quickly out of the car... that's part of the reason why many race cars don't run with an open header. Exhaust systems assist in scavenging.

[cb9tunerguy]

thank you skunk. i was just about to say the same.

[deevergote]

thank you skunk. i was just about to say the same.

And Accord R33 said it about 5 posts before that... Who cares!?

You know, I've actually seen threads that were asking about a comparison between two different brands of headers, and the poster was corrected... even though they rightfully pluralized the word within the context of the question.

ONE post about the singularity of the I4 header is fine... we don't need backup. 10 people saying "yeah, only one header" does nothing... nothing but drive me insane.

[1990HybridCB7]

Thanks DEV, I know there is only one HEADER, so I added an s , don't gotta mke a big deal about it, you don't make me out to seem like some kind of idiot. So you were talking about back pressure earlier , I was thinking about just adding a straight pipe and going with that and than switch over to the cat come emissions(Gotta get it every 2 years out here in Maryland) but some people were telling me i'll lose power without the back pressure, if this is true how will that happen? Should I just go with a high flow cat and will that pass emissions? Also about the exhaust, 2.5" is my best bet right? why not go with 3"? So if I'm not really trying to spend $600 on some header, is there anything else I could get(Kamikaze maybe?) or just stick with the stock one?

[deevergote]

Your best bet with the cat is either to get a proper sized one (stock is fairly free flowing, 'performance' ones like Carsound are better) or get a straight pipe. The cat is honestly the best way to go. You might lose half a horsepower with a good cat as opposed to the straight pipe, but your car will sound and smell much better. Plus, you won't be destroying the environment! You might want to invest in a straight pipe for track use, if you plan on running the strip on occasion. My friend swears that the switch helps him...

Backpressure is never good. You always want to minimize that. Whoever says you need backpressure doesn't know what they're talking about. Too much backpressure (resulting from the engine putting out more than the exhaust is capable of disposing of) results in contamination of the intake charge when burned exhaust gasses re-enter the combustion chamber while the exhaust valves are open. That's just taking up room that could be used for power-producing oxygenated air!

HOWEVER, too large of an exhaust (while it seems like a good idea) isn't better either. If the exhaust flow doesn't maintain a high velocity, it will stagnate. Stagnant, turbulant exhaust causes... backpressure. Plus, without proper exhaust flow, there will be little scavenging effect. Ideally, what the intake is sucking in, the exhaust should be sucking out. Like a syphon, a proper exhaust system not only allows the burned gasses to escape, but also aides in pulling the gases from the head.
For the H22, 2.5" is ideal. You only need to go to 3" or more if you go turbo.

As for the header... if you aren't going to spend a fair amount, you're probably better off saving your money and keeping the stock piece. Kamikaze MIGHT be a decent way to go, but I don't know if it's worth it. I'd much rather spend $600 for 15hp than $300 for 5hp! A good header will also complement a good intake, exhaust, and cams. Cams added to a motor with crap parts might add 8hp... but with better parts, you might get 15hp. Remember, it all works together.

Funny as I say this... I have a stock header (and I'm getting a cheap Megan Racing header soon...) I also have a cheap muffler shop exhaust system. And I'm getting cams this spring

[1990HybridCB7]

Ok so back pressure isn't good than right? If I use a striaght pipe will I lose that much back pressure to the point where it is causing more harm than good? So if I were to get a straight pipe and a good cat or high flow cat, the difference would only be half a horsepower? I can do that especially if it will be sounding better than that raspy sound you get which is what we all want to avoid. I was just saying this cause one of the techs at Honda said that you could get 6 hp from a straight pipe alone. Any truth behind that(or will a good cat do the same)? Well I'll be good after I get these questions answered. I undertstand that whole big is toomuch with the exhasut piping, makes sense. I would definetly spend $600 for that rage header but it says that they only saw an increase of 8hp, where could I get a header for $600 that would give me an increase of 18hp. What exactly is that car sound website for the cats you were talking about? What do you think about the cats on Kteller?

[deevergote]

8hp from a header IS a big deal. 18hp headers cost about $1200 and most of them are designed for H22s in Civics (meaning you need to modify your crossmember).

SMSP sells some good cats that supposedly flow VERY well. www.smsproducts.com
CarSound cats have a very good reputation as well. kteller also sells quality parts... I have no knowledge of what they sell (or even what brand they are... I haven't looked) but I've never known them to sell anything but decent stuff. kteller.com is probably the best seller of midrange parts... affordable, though more expensive than some... but the gains and quality are significantly better than the lower end brands.


I wouldn't say 6hp from a straight pipe... it's possible, but I would only say so if that's being compared to an old converter. If you want to give it a try, invest in a pipe. They don't cost all that much. The sound will be horrible, and the smell will make you gag (from my own experience, anyway) but it may be good for track use. Daily driving, get a good cat.

Using a straight pipe has nothing to do losing backpressure... backpressure isn't useful anyway. You want to promote a free-flowing exhaust stream with high velocity. The engine has to be able to put out what it takes in, and it has to do so in a smooth, efficient manner. If the gasses flow too slowly, it won't be as good.


The one thing you NEVER want to do is hollow out your cat. Many people do this, and brag that it's a free power maker... it just creates a chamber for your exhaust gasses to become turbulant. Not good.



So, in order, I would say:

1. QUALITY high-flow cat (no ebay crap_
2. Normal stock cat of a proper size in good condition
3. Straight pipe