questions about headers and cat
 

I have 2.25" piping from the cat back. I currently have a JDM Type R 4-2-1 header on with a test pipe. The actual collector inside diameter is under 2.25" is it not? I know a lot of people are running this set up, so what would be the best size cat to use for this application to provide the best flow?

Because of the anti-reversion chamber in the Type R header, is this a better choice for my 2.25" piping over a true 2.5" header collector (such as Vibrant), since this is basically the stock setup for a JDM Type R?

I can get a 2.25" Comptech header for pretty cheap ... maybe I should get that?

i thought the JDM type r header was a 4-1 design with a 2.5" collector (inside diameter of course)...pretty much the same as a mugen...if you want less restriction, go with the same size are your collector/piping, cuz the smallest point will negate any effect a larger pipe will have on flow...

I know there are a lot of people running 2.25" piping ... what header are they running?

what are the engines future plans?

never mind I went with the comptech