GSR

is the jdm dc sports 4-1 header just for the ITR? does it fit a civic Si? good gains?

DragII

JDM dc sports?

GSR

yeah that header

GSR

does this header bolt on to the stock cat back?

DragII

umm what possible differance could there be between a JDM DC Sports header, and the one the sell to US customers?

I think you have your products mixed up.

if you are talking about the stock JDM header....you can refer to the post that was just created on that topic

Padawan

The JDM DC 4-1 header will bolt right up to the head, but not to the stock cat. You will need either a 2.5" cat or a 2.5" test pipe to install it. Both Mike at IPS Racing and Dave at SMSP carry 2.5" Carsound cats for your application. Gains should be substantially better than a US spec. header, depending on your setup and mods.

GSR

what if u get 2.5 piping exhaust would that bolt right up to the header?

B18C-EJ1

No, you need a 2.5" cat too. Unless you bypass it, then it'll work fine.