Thread: Exhaust Modifications.

Mods:
K20A2
Stock from valve cover to oil pan
RBC manifold
11" intake with velocity stack/filter combo
Tri-Y long tube header
3" Thermal exhaust

This is the RSX dyno. The dotted lines represent the 2.5" exhaust and the solid lines are 3". I see no low/mid range power loss, only gains. Quite impressive on a n/a car. And the car was dyno'd, not the engine... so yes.. Wheel horsepower.

I also said IM SORRY. I didnt realize we were just talking about just catbacks. 3" headers to 5" cat backs would be useless. But a FULL 3" exhaust vs a FULL 2.5" exhaust is beneficial, especially with bigger mods..

Anyways back to what the Original poster wanted to know.

What if he has big future mods planned for the car? Not to mention, I have already said I was talking full exhaust not just catback. And It doesnt mean he has to go waste his money on an exspensive catback either. He could do 3" custom mandrel bent exhaust and save his money..

3" was just MY OPINION.

I said with a high flow cat and big resonators (to help eliminate drone) if you read my post. 3" will just keep his options open for future mods if he wants to go bigger...

what about downpipe size? i am looking into getting one and im not sure what size to get. im gonna run catless either way but should i get 2.5 or the 3in? would the 3in hurt my top end? and the 2.5 doesnt sound like its too much bigger from the factory dp. idk what to get. help me. lol. oh, and for mods i have mildly p&p sc, tb, heads, and the 3.4 pulley(yeah i know), 180 thermo, 104s, msd 8.5s, big ass K&N filter, resonator delete(im gonna get a glasspack once i get the dp). sorry if im hackin this thread. lol.

I would get the 3" dp. Only way to go

Originally Posted by Bio248

this guy is right because headers are so cheap now. by the time you have a 3" downpipe and a plog you could have bought a cheap set of headers and had a better performance package.

but if you insist, get a 3" downpipe. a 2.5" is a little on the small side for a blown car.

well cant i just buy headers later on? i dont have money for them now so i just want the dp but then headers in the summer.

Originally Posted by Bio248

you could, but itd be a waste spending money twice. i would save up for just a little longer and go for the big toys right away.

oh so the headers come with a downpipe?

Originally Posted by Bio248

yes.

ohhhh. i see. damn that is a waste of money then. lol. oh well