Plenum Volume

Hey Rob!
I'm not familiar with the runner shape of that manifold, but in figuring runner volume you can get close using the L*W*H for a rectangular runner, 3.14*Radius squared*H for a round runner and 4/3*3.14*R1*R2*R3 for an oval. Obviously the curvature and taper of the runner will be difficult to factor in. As for a pyramid shaped plenum, L*W*H/3.
Anyway, back to the Indy tunnel ram issue. In doing more research it seems that even Indy feels it's undersized as they offer a plenum spacer to raise the top plate by 1/2". Go figure!