Exhaust Question

[JtWo]

If I were to build my own exhaust, and used a Y pipe that was a 3" inlet and 2.5" dual outlet for a dual muffler set up, would the flow be the same as a 3" muffler?

 

[BorHor]

Thats what I want to do. And I remember seeing an equation for this before and 2 2.5" was just a tad larger flow then a 3" so it is a good match up.

 

[JtWo]

Sick. Dood someone side swiped my supra while it was parked. I parked it in a place where it should have never been hit -_-

 

[A-to-the-J]

DAMN! another one? i guess i have to jump on my exhaust project then. damn, so many things i want to do, so little money