spacetrucker wrote:Welcome to the forum...
did you try a muffler shop? they have and do all types of pipe..
Thanks for the welcomes, all.
...so just (finally) figured out that extending the chimney down to the grate was slowing down the flow of air so I pulled it off before today's experiment, a 2.5 lb pork loin. Temp initially soared pretty quickly up to 300. I wasn't ready for that since a full basket of charcoal (12" x 12" x 6" - over half a bag of charcoal) was getting me up to 225 tops(intake and exhaust vents wide open). I got it down to 225/230 pretty quick and that's pretty much where it stayed after that (vent only 1/4 to 1/3 open). The pork loin was delicious and juicy and was in there for about 3 hours.
So, my lesson learned was that just because somebody had good luck with a mod of some sort that you watched on YouTube, doesn't mean that mod will work for you in the context of all your other mods. I think the heat baffle I made is extremely efficient because there is only a difference of about 10 degrees from one side to the other. Because it pushes the heat down, the natural rise of the heat through the different sized holes alone (smaller holes on fire side) fixes the heat distribution problem and temps are pretty controllable and consistent across the entire grate. The chimney lowering was not helping because it was also restricting flow by taking the exhaust pipe diameter down an inch or so. I was having such a good time over-engineering problems I didn't even have, I didn't realize that I had moved into downgrade territory with all my simultaneous upgrades. Could have been worse experiments to toil with.
Wish I got one of these earlier on.