This tread is to set the record straight about exhaust manifolds (headers) or in OUR case...header.

First questions:

When keeping the CAT intact, someone like me would have to use the CT Header (I live in Ca.). In this case, would an after market header help with power at all? It is my opinion that it wouldn't, but feel free to set me straight.


Second question:

The 4-2-1 is said to be a better design than OEM style 4-1 for power. Why isn't the OEM manifold built as a 4-2-1 then?


Finally, please supply links to dyno charts proving that aftermarket headers do more than make more noise.

Thank you.

 

i haven't installed my race header yet, but it's been said that it generally is NOT worth it to install an aftermarket header on our cars unless it's going to be cat-less.

 

have you looked down the oem downpipe/cat?
that would answer your second question.

 

The CT "header" is nearly identical to the OEM header. I highly doubt it provides more than a 2hp gain. The OEM header is designed to improve fuel economy and keep emissions in check.

And...the race headers with a cat are still badass. They just don't provide as much power as the cat-less ones. The Vibrant RH with the cat is definitely a huge improvement over stock. I'd never pay money for a header with a cat, but for those who do, it's a good investment.

 

A shorty header does not give good gains, you do need a real 4-2-1 race header to see significant changes in power. It has been done where you can include a cat but it is not easy.

Honda doesn't put the 4-2-1 in because its a) a pain to get a cat in there (most people do not do this) and b) its way more money (you will pay minimum 500 and thats for a knockoff, the big boys are around 800+). Also, those who do install a cat put a high flow in there to reduce resistance and keep air flow high.

If you want to see dyno's, go to 8th civic.com and search in the bolt on's section. There are tons of these for multiple headers.

 

^i got my s2rh brand new and installed for less than 800 lol

but the oem design is actually a 4-2-1.
just look at the inside of the down pipe.
its split in the middle then goes from 2-1.
but its a brief 2 section though.

 

Will the Skunk2 Header meet the the catback exhaust pipe in the proper location, once the CAT is eliminated?
http://www.skunk2.com/mm5/merchant.m...de=412-05-0930

 

hmm I didn't know that! Thanks

and I am up in Canada, finding it for 800 without shipping is about the best I can do. Everything is more expensive up here....

 

why not just get a nice header and save the stock one for whatever inspections you guys have? also, the pics don't work.

 

Well there are something you have to consider. A good 4-2-1 header that is tuned for a specific set-up will always be the best performing header. If you ever talk to the makers of custom headers, they want specifics on what's done to your car before they make the header. This is because someone with basic bolt-ons will get a slightly different header than the guy with a full NA build.

Get a good 4-1 header with a Random Tech HFC downpipe and remove the badge. Most inspectors will think it's stock. This is prolly the best mod and forget possibility out there.

 

yes it does. the s2rh comes with a 3 bolt to 2 bolt adapter also
but it does bolt up perfectly. i think i still have a pic either on my laptop or on my photobucket.

 

oh yea lol
i didnt know you were in canada.
but yes its more expensive because of customs and the extra distance.
just curious, what part of canada are you located?
i have a friend up in vancouver, bc

 

Kingston, Ontario

Its about 2 hours west of Ottawa and 2.5 hours east of Toronto. Its the biggest city between Toronto and Ottawa.

 

^oh thats cool man. i've been to calgary for iaft.
that place is cooooooollllllllllld as f*ck!!
and i've been to riviere rouge. idk if you've heard of that place.
its in quebec

 

haha most of Canada is cold as **** in the winter. I haven't heard of that place in Quebec, but we go to Tremblant for skiing/snowboarding and that place is awesome

 

^i think its actually considered grenvile. but i stayed in a cabin over there.
i think the tremblant airport has riviere rouge in the name. its an international airport

 

didn't know that! Its a 5 hour drive for me so I just ball out and go. No planes!

 

Good info here. Thanks.

Here are the pics I originally tried to post.

1)OEM
2) CT Short manifold
3) DC 421
4) Skunk 421

 

Megan Racing also makes a shorty header for the Si. It's way cheaper than CT.

 

Both a waste of money...regardless of price.

 

for 550 bucks or however much the ct header is, you can get a dcrh for 390 and put out more than double of what that shorty header does.

 

You can get a KiddRacing one for $425 and apparently put out power numbers equal to the SSR.

 

agreed

 

if you look at how short the runners are on teh stock and CT compared to the S2rh or the DCRH. The primaries are so much longer and the spot where it goes to 2 is long as well. this is what makes the Raceheaders put out more power. If you add anything restricitive (resinator cat of high flow cat) you are just slowing the airflow and loosing power.

 

You're not losing any power when you buy a catted race header. You're just not gaining as much.