hey guys i just got a gsr swap and i just picked up a mugen 4-1 type r header with a 2.5 collector now what are u guys suggesting for the exhuast size 2.25 or 2.5 or is 2.5 too big?? i also head comparys like dc and apex use 2.5 for there gsr catback systems

any help would be apretiated

 

I like 2.5 on my N/A set ups, but 2.25 will work also. You need to have a muffler shop weld in a reducer if you're going to run a catalytic converter.
Companys like Apex and DC make cat backs that are under 2.5inch.

 

i was thinking since i have the 4-1 header with 2.5 collector id do 2.5 exhaust to an apex i exhuast