2.25 or 2.5 exaust

[CrackerTeg]

That all depends on what your final numbers will be. Best bet is to start with a 2.25" setup and tune from there. If you feel like you can pull more power with a larger exhaust, get a 2.5" bent up. Sure it sounds like some coin to be spent but it all depends on your final goal. Check out k20a.org for those questions. Granted, those guys are dropping k's into older chassis' but at least you'll get a good idea as to what you could expect.

[timot_one]

A built motor is a different story.  You'll probably want to go with a 2.5" exhaust instead.  Considering you'll be running those BP Stage 3's, having your exhaust breathe better will be helpful.  I'd also consider an aftermarket high flow cat instead of an OEM cat.  You can get a Magnaflow high flow cat with 2.5" in and out for a decent price.

[asnstyle22]

hrm.. my tuner suggested i get a full 3" and said if i must, run a 06+ civic si cat or rsx-s cat.... are those better flowing than a 06+ tsx cat? anyone know?

i might just do the 3" but it cost so much.... anyone happen to have the schematics to the pipinglength and bends so i can order parts online? thanks!

[CrackerTeg]

Running a larger exhaust with a bottleneck of an OEM cat isn't going to give you good results. I'd suggest going with what Tim suggested with a 2.5" exhaust and an aftermarket high flow cat and you'll get a better flow without the bottleneck your "tuner" is suggesting you do.

[Icebox]

^ 3in is overkill unless you are going big turbo.

[asnstyle22]

eh.. i guess i needed to clarify, he wanted me to run 3" wih test pipe but i said i wanted a cat just cuz i would rather sacrafice a few hp and lower the emissions. and he knows i didnt want the exhaust too loud so he said i can run a 2.5 with a 06+ civic si cat or rsx cat, so i was assuming they were high flow and just wanted to see if anyone know how they compare to the 06+ tsx cat since i already have one of those sittin around

i did express my concerns about the 3" but he sad its fine for my engine since it is high compression with bigass cams.

was thinkin bout doing what nva-av6 over on v6p did with the 3" so i gotta save $ for it since its over 1g for the exhaust...

[Icebox]

nva-av6 is a mod over here, so you may want to send him a pm and ask his advice.

[timot_one]

I'll let you know right now, a 3" exhaust on a K24 is going to be wicked loud.  Trust me, I've heard one and it's awesome!!  Either way, I'd still consider an aftermarket cat if you insist on running a cat.  I'm pretty sure it will flow a lot better than an OEM cat.

[asnstyle22]

yea... probably going to go for aftermarket cat... saw ADI's video and his didnt seem THAT loud... i wish there was some before and after clips so i can tell relative to the device used... nobody ever gets before the installation =T im gonna ask ADI for in cabin sound clip.

now, i gotta measure the lengths and bends so i can possibly order parts online and just have somebody local do the actual welding...

anyone interested in the schematics after i get it? maybe gonna be  awhile though.. my last final is this friday then im working straight through winterbreak until the new quarter begins so not much time to mess around the car.