I own a 2003 V-Limited STI. Twin Scroll JDM. i want to decat the downpipe, my exhaust that is on the car is very nice looking and is a fujitsubo jasma which is one piece stainless right up to the downpipe. i want to retain my fujitsubo exhaust as they are regarded as one the best makers of exhausts in japan that retain performance with a quieter sound.
My question is what size is my fujitsubo exhaust? i have googled it and it only comes up with 3".....my downpipe if standard with it being a twin scroll set up i assume is a 2.5",..so how is this possible? so the exhaust must either be 2.5" or my downpipe is 3" as standard on a twin scroll...i dont know! what size is a standard twin scroll downpipe. and do i buy a hayward and scott 3" > 2.5" downpipe or a roger clark 3" downpipe. also roger clark state there are 2 sizes of downpipe in length from the hanger being 12.5" or 17". i am dead confused lol and how much are fujitsubo exhausts worth if i were to just ditch the lot and do the whole 3" roger clark route for £792.00 any help will be appreciated

 

A bit more research and it seems my exhaust is a 2.5" flange which then goes into a 3" straight through from catback to back box which is all one piece. so it seems the downpipe is standard 2.5" and gives me the option of a downpipe from hayward and scott which is 3">2.5" which will mate up to my fujitsubo exhaust nicely i hope. just have to measure the length of the downpipe i need now and remap away.