Well this past weekend I finally got sometime to do some experimenting and I figured out the issue. But here is a run down on my set up.
Here is my truck, trailer, mower, and leaf box
Here is my mower and bagger set up, as I said before its a 2010 Z910A john deere with 110 hours on it with suspension seat, this thing is awesome. I love it, it cuts so nice, leaves a nice stripe, and runs so smooth. The bagger unit is a protera dump from the seat, with a john deere power head unit.
As you can see in the pics that there really isn't any big turns in the tube to restrict the air flow of the clippings going into the hopper, its all the same size tubing. So instead of taking the tube off I just drove around with the back open with the mower on, and while I was doing that I had ZERO leaves being blown out. So I was right with just not enough flow coming out of the hopper. I would like to try and figure out a way to get more air flow out of it but its a 1500 dollar hopper that I don't want to go cut up and try and fix. So I guess Im just going to have to deal with it. Here are some pics of the inside of the hopper and the area where the air flow comes out.