I understand that a larger runner will slow down the air flow. Why not put the mirror finish on the inside of the runner to speed up the flow with the same size runner. Less drag on the air. I polished my rims and they are sleek. I think i will try it when i find a spare set of runners. Any fair input is welcome.

 

Good luck polishing the inside of those tubes. Extrude honing is about the only way to "work" the insides of them.