The K&N filter, Quad Ram Air, heavily modified air box, and crankcase vent mod / filter / ram all work together very nicely for a huge gain in performance and fuel economy. I saw a 57.9% increase in fuel economy (but I wasn't getting the stock EPA fuel economy rating, it nets a 20% improvement over the EPA rating). Horsepower based on 1/4 mile time says I gained 36.6% (34 HP), which I account mainly to the very poor breathing of the stock 2.2.
Sorry but when I see dyno numbers, I will believe this. Even with a debaffled airbox you still have two 90 degree bends in the airpath, and assuming it has picked up some velocity from less resistance, it will still smack into that last 90 degree right after the TB slowing down the port velocity.
You stated (on Moparchat) he also has a ported head, cam, UDP, before he did this mod. I didn't seem to see that mentioned on the same page, and it is probably vital to the validity of his claimed increase. If anything I seriously doubt his 34hp increase came from some simple induction mods with the stock intake flow. In fact with the TBI manifold I find it hard to believe any induction mod can make a 34hp difference (aside from turbo or supercharging)
Its great that he is trying to help out other people with their mods, but he needs to take his formula calculations with a grain of salt.
Even with technology today, where engineers can design and test something on a computer, they still cannot predict everything that will happen in the real world.
Real Life > Formulas