Good afternoon.
I will be looking at building a FWI for my 04 but I'm keeping an eye on ebay for filters. It's real cold outside in southern ontario Canada so I would just like to know what size filter I would need. Mostly, what flange size would I require. I've heard that a 3" would do but I've seen many sizes out there. If I was to remove the factory air box and slap in the filter at the end of the oem pipe, what would the id size need to be to slide over the pipe? I know that's not the setup for a fwi but that will help me figure out the piping size, flange size for the filter, etc. I know it should be very easy for me to figure out by unconnecting everything but like I said, it's real cold outside so I'd rather pick the brain of someone that would know the size off the top of his/her head.

Thank you in advance.