Alrighty, now for the 2nd pie.
I let the hearth temp come down to regular loading temps of 600. Flipped the vent lid up and left about 40% of the opening exposed for airflow. I want to note that when I shut the vent lid further, I did notice a change in the way the airflow sounded. It sounded muted and weakened. As is though, the sound was unchanged.
After 30 seconds of baking, I lifted the lid and notice really great oven spring towards the back. There was a huge bubble there. I noted that the rest of the rim was so so at this point. Not good. If there was a postive effect, I would have seen it at this point. I turned the pie 180 degrees and continued baking. The vent lid was put down after 1.5 minutes or so and the rest of the bake was done with the lid down.
Well, I got great spring in only one portion of the rim and one portion was actually FLAT! Don't know what happened. This wasn't suppose to happen. Goes against my theory and purpose for the mod.
2nd, bummer was that the bottom burned as well. To the same degree as the first pie despite loading at 600F and not 720F. Weird...
2 possible reasons for this. 1) The dough was a bit overfermented, which I don't really believe is the reason, but it's possible. 2) Jet Deck is correct in that when the airflow is blocked the hearth will get more heat. I initially didn't think this was possible since i do still have the sand bowl buffer underneath, but at this point I'm willing to entertain any/all possibilities.
Recap on pie #2
-loaded at a hearth temp of 600f. Bottom still burned.
-Oven spring was better than pie #1 in only 1 portion of the pie.
-There was a flat portion of rim too. Dunno how this happened since I opend the skin up to the same size and fairly consistent with my opening methods ie didn't press the rim.
-didn't timed the bake but it was around the usual bake time.