I would not say its speculation, its a given fact that cold air will increase the hp.. even if you dont see it on the dyno,,, actually who cares if you see it on the dyno,, if you put a temp reader in the air and you can see its going into the motor 100 degrees cooler.. its a fact that your going to produce major hp increase... we just need to get the air up there cold, i think pull off the lower air intakes that go to the brakes, insulate the pipe, and you have a winner...
as well you dont even need a wind tunnel as your not looking for the ram air effect...and you will never get the ram air effect no matter how fast you go.. we'll i think you will get a little less than 1psi at 80mph... we had a member do a wind calculation for us years ago...
so its not about the ram air creating power,, its about getting fresh cold air into the motor... and you could achieve that with any shop fan in front of the truck on the dyno..