New Cat

[nissin67]

I want to speed up my hatch a little... does a high-flow CAT helps??? i have a ractive muffler already... do i need to change the pipe b/w the CAT and the muffler as well?? if yes, what size??

anyhow, how much hp does that little CAT give me..???

 

[civickidd99]

I've heard both ways! On one side, your stock stuff is choking your car, but on the flipside too big and you'll lose back pressure. You're best bet would be to have a custom cat-back made. It's actually cheaper than you think! Go no bigger than 2.5".

 

[2kstreetcivic]

If you are going to change the size if the exhaust pipe you are running, dont get a bigger pipe than 2.5"......I wouldnt get a pipe bigger than 2.25" but you can go up to 2.5"...the reason for this is that civic thrive on back pressure and if the pipe is bigger than 2.5" than you start to lose that back pressure and you actually lose horse power