A coworker of mine and I were talking about aftermarket exhuasts today at work, when the subject was moved to fabbing up our own custom headers and mufflers etc. Started looking around and we have enough thin wall pipe laying around we can't use anymore to fab up some headers, and was wondering if any of you could provide me with dimensions? Looking for I.D. and O.D.'s of the pipes, bend radiuses, distances, etc. I'm planning on playing around seeing what does what with different bends etc, but hoping to start from a proven design first and go custom from there. edit: needed to add for the 650R.