Hello, I know this may not new question. But lazy to find out. 1Q) I wonder both ITR 4-2-1 and 4-1 Collector size is same 2.5" or 2.25". I know CTR 4-2-1 is 2.25. Maybe ITR should be bigger? 2Q) Look at picture ITR 96 & ITR 98 could be bigger piping diameters than CTR from bottle neckto exhaust? thanks

http://www.isitaboat.co.uk/cars/hond...es/004-006.jpg

 

Both have the same collector size.

 

It's 2.5". I have one and I measured when I installed it.