Update on the mods I made. I will post later the exact mods I made with parts and pictures
I put the 3 inch dryer vent in. That helped some. It took longer than expexted for the stack to actually start drawing the heat and smoke into it.
I added 3 thermometers at grate level. One near the new vent stack. It ran the lowest of the temps. Two are on the front and one on the back left corner if facing the main chamber. All attached to the lid.
I put a 16 gauge steel plate over the opening where the heat leaves the firebox and enters the main chamber. I obviously left some opening for the heat to draw in.
Main chamber: I put 1x1 angle iron runs down both sides. This was a bit more difficult than I had thought. I used 22 gauge sheet steel to make different size baffles and opeings. I have 1 8x17.5" and 2 6x17.5" and one 4x17.5" plates. I also have 1 6x17.5"-16 gauge steel plate closest to the side fire box. I can make varying spaces for the smoke and heat to pull.
Side fire box: I also put 1x1 angle iron runs down both sides. Hard to install, but necessary. I found a charbroil(?) replacement iron grate (very heavy duty) that I cut 2 small rows off of and it fits perfectly. Now I have a very heavy duty coal/wood holder. Lots of good air flow.
Initial results: I ran a load of charcoal last night. Just 1 chimney worth.
It took longer than expected for the vent stack to pull well. I think that it is possible that the Outlaw needs to have a larger diameter chimney, due to the volume size of the chamber.(just a stray thought) Temps were not coming up to the 200+ area with just charcoal so I added 1 piece of junk firewood. Temps began to rise nicely. One curiosity. The front right therm showed the highest of all the temps, the therm closest to the vent stack was the lowest, and the one in the back left was in the middle. I also tried closing down the intake vent at one point to about 20% airflow or so, and the temps dropped dramaticly. I believe that I will have to run this thing wide open. Of course fuel type and amount will dictate. Over all the temps were much more even and the 1/3 of the grill surface closest to the firebox was finally usable.
I will post more later. I hope to run 7-8 butts later this week. We have none left in the freezer.