Scott123 said:
“Fabricate an insert, and pre-heat the oven with and without it. If the insert doesn't trim off at least 1/4 of the pre-heat time (and use at least 1/4 less wood to reach the same temps), I'll eat my hat”
Well, it is way too early to set the table for a hat feast, but the kitchen staff may be cooking it up.
Given that Antoine invited us to report out, I will share my limited experience so far.
I have the FGM 700, with the higher dome, door. I picked it for the versatility (not sure yet if that was necessary but I hope to have this for years to come) of fitting anything in there, regardless of height.
I have been a bit frustrated with achieving high temperatures, in terms of wood and time, as well as top heat. Top heat, as an issue, seems to be real but minor. A little bit of doming seems to take care of things. And, in researching many threads, that does not seem at all unusual.
In terms of time/temperature to reach Neapolitan levels, it does take a long time and a lot of wood. I know the oven is well insulated and the mass adds time. Antoine and I have had an ongoing conversation about this and he has provided great coaching/feedback.
He is convinced that I will get better results by using a different wood, e.g. well seasoned oak. I am using almond wood and it is, supposedly, well seasoned. I do get hissing in burning some logs and I do get significant smoke for perhaps 30 minutes or so when starting. I get major amounts of coals as the wood burns. But, it is what it is, I have at least 2 months to go with this wood.
In terms of comparison testing, I do not think it matters, since I am testing the oven with and without the insert. Obviously, it is good to maintain consistency in all other conditions.
I have only one “paired sample”, so right now n=1. That is why I am sure it is not hat meal time, at least yet.
But, this initial result was not encouraging.
2 weekends ago, I decided to try to minimize heat up time and not worry at all about wood consumption. So, I stuffed the oven with wood and kept stuffing it to keep a big fire going at all times. I was actually not making pizza that day, I was making some eggplant parmesan. So, I stopped a bit early before achieving very high neapolitan temperatures.
Last weekend, I tried to follow the same process with the insert (having just received it). I did not duplicate everything exactly – I did not weigh and count sticks of wood and time when they were placed in the oven. And the first time was a windier and cooler day than the second. But, with those caveats and more, I followed the same approach and here is the comparison (temperature is degrees Celsius using the FGM thermometer)
No Throat Reducer Throat Reducer
1:00 140 150
1:15 205
1:30 220 250
1:45 280
2:00 295 310
2:15 335
2:30 355 stopped adding wood 360
2:45 380
3 :00 400 410 (one last log)
stopped
3:15 430
3:30 460 (raked out coals)
4:00 460 (bake)
Comparing my results after 2:30 (after that, the comparison cannot be made since I stopped adding one in one of the heat ups), the results are identical! The heat up curves do seem to be bit different.
I also can observe that the throat reducer gave a clear advantage in terms of smoke. With it, all of the startup smoke went up the chimney. Without it, I get a lot coming out the front for the first.
The pizza picture is from the session using the insert. Baked in 1:28 including doming. The cheese was whatever was sitting around in the house with some cut up tomatoes. The oven picture is the coal bed when I stopped adding wood.
My hope is that Scott save his appetite for pizza since I really want the new gizmo to make a difference!

Comments and guidance welcome.
- Mitch