H22 swap exhaust

[CB9_IS_2_BETTER]

I am curious about exhaust diameters after doing an h swap. Does using the same smaller diameter accord exhaust (I believe 2") create too much backpressure for the new engine? I am replacing my exhaust regardless and would like to get whatever will be ideal for a stock h22a. Thanks

[sonikaccord]

2.5" should be good enough for a stock, healthy H22A.
2" is on the small end for that engine, imo.

[CB9_IS_2_BETTER]

Thanks, I know very little about exhaust systems and all help is appreciated. I will measure my exhaust after work to find out for sure, but do you have any opinions on just buying a catback setup vs taking it to an exhaust shop. I see some reasonably priced catback systems online but I don't know about quality, I also don't have a cat in my car currently, just a crappy muffler the rest is straight piped. I want to put in whatever will be best for my car. Thanks

[CB9_IS_2_BETTER]

Looks like I am actually at 2.25 right now, would it still be advantageous for me to go up to 2.5?

[deevergote]

Install a cat.
Otherwise, 2.25” or 2.5” is fine. Narrower will give you a bit more power down low, and cost you a bit up high. Since most of your diving will in the lower RPM range, you’ll probably get more use from 2.25”. If it sounds good, that’s all that really matters. Many Japanese exhaust systems, and probably the cheap knockoff copies, are 60mm... which is roughly 2.36”.
If you like it loud, get a small can and no resonators. If you want it quiet, run a big can and the longest resonators you can fit.
But seriously, install a cat.

[CB9_IS_2_BETTER]

Ok thanks, I will probably keep it at 2.25 or 60 mils then for lower end power, but I was planning on putting a cat in with the new system. My exhaust fell off a while ago and all I could afford was the cheapest they could do, it's time to fix that. I want it to be on the quiet side but sound decent so I will probably be looking for a decent sized resonator. Thanks again

[CB9_IS_2_BETTER]

Do you guys know if the cat flanges are the same for the F and H? I am looking at possibly getting a catback and buying a cat then taking it to a weld shop. I think I will have to find a downpipe at a junkyard to get the engine side flange for the cat, but am just curious if it is the same for prelude and accord.

[deevergote]

They should be.

[CB9_IS_2_BETTER]

Ok thanks, I might just end up getting a new downpipe and a catback then just buy a cat and bolt it all together, but I have read a few things about the fitment of aftermarket catbacks on the wagons so I am hesitant.

[deevergote]

Yeah, the wagon fitment is different. You can modify a sedan/coupe exhaust, or better yet, just have a reputable shop build you something. I went that route, and never regretted it.

Might as well just buy a complete header. Megan Racing and OBX make decent ones for reasonable prices.

[CB9_IS_2_BETTER]

Yea I know someone who welds exhausts on the side, I was still looking online to see which should be cheaper, I don't have a ton of money to throw on this but hate my current setup and anything will be better. I am also really indecisive and still deciding between 2.25 and 2.5 haha

[sonikaccord]

Get whatever is cheaper. Budget first.

[Corweena]

Since you have a wagon, I'd definitely recommend going with a custom setup. Get your cat, and a good resonator and whatever muffler you decide you want to run, and a nice exhaust tip. Take it all to an exhaust shop and have them cut/bend/weld a custom setup for your wagon. Easiest way to go about it, and will be probably be a good amount cheaper than buying a quality catback for a coupe/sedan and then have to chop it up to fit.

You could even play with getting a larger collector for your header downpipe....most of the bolt on ones Like Megan or OBX only have stock H22 size collector or a just a tad bigger. You could jump up to a 2.5 collector, then run a 2.5" cat and piping all the way back. Will open up the flow for if you want to make more power down the road. You are already doing the work, may as well add a bit more now, and not have to touch it in the future.

[CB9_IS_2_BETTER]

Thanks a lot, I do plan on doing more building in the future so that might be a good idea to go 2.5 now. Get it all done at once. And the collector is the length of downpipe after all the pipes merge together correct? Also, any mufflers or resonators you would reccomend? I currently only have a really crappy muffler and nothing else so I’m coming in pretty much from scratch. Thanks

[deevergote]

That’s correct on the collector. You can find decent collectors from Burns Stainless. Not cheap, but very well made. You might also want to consider a higher quality header, like DC Sports. Adding a new merge collector isn’t cheap, so it’s a better idea to do it to a header that is going to last longer than the brands I mentioned. It’s a worthwhile mod, though.

Resonators, just get the proper length. Longest you can fit. Brand doesn’t matter that much.
Muffler, it depends on what you’re going for. A nice fat can like the Apexi World Sport will be quiet and look pretty cool. Personally, I had a generic dual tip muffler that my muffler shop had on hand. No idea what brand it was, but it sounded great. Loud, though. The bigger the can, the quieter it will be.
Cat, buy OEM style. No high-flow, no “racing”. Buy quality, so it’ll last. The originals tended to last 20+ years.