air? I'm no engineer but if I try to visualize it I see the air flowing past the tb's at high velocity and because of it's momentum it is heading straight back towards the back of the plenum(somewhat bypassing the front and middle) where it meets the 90 degree bend and ends up flowing more to the rear cylinders. Am I on track here?
Does this also explain why many intakes will have a squared or rounded end/pocket that goes beyond the rear-most runner?