brewersfan73
Well-known member
The alternate title for this thread was "I had some extra time and pellets to waste, and I thought I'd bore this group and share my results" 
Before I upgraded my Austin XL with a PID controller (I'll post that thread soon), I wanted to take some temperature readings with the old stock controller before I stuck it in a box and lost it in my garage. I was looking to get a baseline of different scenarios so I could compare them to the performance of the new PID controller. I thought I'd share what I did in case anyone has some of the same questions or was curious as to what the different mods do. Remember (as has been discussed on this forum many times), everyone's grill behaves differently (even the same model), so there is no guarantee that your results will be the same. As with other threads that I've started, I'll apologize in advance for the length of this post.
I've got three different mods for my grill:
1. 4-Window Flame Tamer
2. Heat Deflector/Air Gap mod
3. Removing the large Pit Boss heat diffuser plate
For my purposes, there isn't any reason not to use the flame tamer for smoking, so I didn't conduct any tests with it removed. The only time I don't use it is if I plan to do a reverse sear and open up the searing plate. Here were my planned tests:
For reference, here is an example of the setup for Test #1:
And here is the setup for Test #3 with the large heat diffuser plate removed:
Finally, here is the position of the 4 Inkbird temperature probes. I colored coded the labels so they match the graphs:
I ran all of the tests at 225 degrees F.
Here are the results. The graphs should all be at the same scale. It is a snapshot of a 30-minute window after the grill had settled down. The vertical temperature axis is roughly the same for all graphs (there is a 16 degree difference between each of the horizontal lines). I did this so that you can see quickly which tests had bigger temperature swings.
Test #1:
Test #2:
Test #3:
Test #4:
Without diving into all the different calculations (difference between probes at high/low/average, total temp swing by probe, average temp vs 225, etc.), you can tell by the graphs that Test #3 was probably the best scenario. Temperature swings (peaks vs valleys) were much less than the other scenarios, temperature difference between probes was adequate (although sometimes probe #1 (red) got hotter than expected vs the rest of them), and the average temperature during the cook stayed pretty close to 225.
Test #1 had acceptable temp swings (for a non-PID controller), except it ran much hotter than the 225 set point.
Test #2 had really big temp swings, but at least the average was around 225.
Test #4 was the worst - big temp swings and much lower average temperatures.
The other thing you can see is how often the grill cycled during the 30-minute period. With the air gap mod installed, there were more cycles with less of a temp swing. With the mod removed, there were fewer cycles and much larger temp swings.
In actual real world cooking experience, I've been usually running with the scenario I used in Test #3. I've been very happy with the results and honestly, I'd be perfectly happy without my new controller. But I am going to enjoy having many more temperature set points. The big gap between 250 and 300 degrees on the dial has driven me a little crazy on a couple of cooks.
When I post my controller upgrade thread, I will add similar graphs to show the performance difference. Spoiler alert: the graphs are a lot tighter with the PID controller. That shouldn't be any surprise.
If anyone has any questions, I will try my best to answer.
Before I upgraded my Austin XL with a PID controller (I'll post that thread soon), I wanted to take some temperature readings with the old stock controller before I stuck it in a box and lost it in my garage. I was looking to get a baseline of different scenarios so I could compare them to the performance of the new PID controller. I thought I'd share what I did in case anyone has some of the same questions or was curious as to what the different mods do. Remember (as has been discussed on this forum many times), everyone's grill behaves differently (even the same model), so there is no guarantee that your results will be the same. As with other threads that I've started, I'll apologize in advance for the length of this post.
I've got three different mods for my grill:
1. 4-Window Flame Tamer
2. Heat Deflector/Air Gap mod
3. Removing the large Pit Boss heat diffuser plate
For my purposes, there isn't any reason not to use the flame tamer for smoking, so I didn't conduct any tests with it removed. The only time I don't use it is if I plan to do a reverse sear and open up the searing plate. Here were my planned tests:
For reference, here is an example of the setup for Test #1:
And here is the setup for Test #3 with the large heat diffuser plate removed:
Finally, here is the position of the 4 Inkbird temperature probes. I colored coded the labels so they match the graphs:
I ran all of the tests at 225 degrees F.
Here are the results. The graphs should all be at the same scale. It is a snapshot of a 30-minute window after the grill had settled down. The vertical temperature axis is roughly the same for all graphs (there is a 16 degree difference between each of the horizontal lines). I did this so that you can see quickly which tests had bigger temperature swings.
Test #1:
Test #2:
Test #3:
Test #4:
Without diving into all the different calculations (difference between probes at high/low/average, total temp swing by probe, average temp vs 225, etc.), you can tell by the graphs that Test #3 was probably the best scenario. Temperature swings (peaks vs valleys) were much less than the other scenarios, temperature difference between probes was adequate (although sometimes probe #1 (red) got hotter than expected vs the rest of them), and the average temperature during the cook stayed pretty close to 225.
Test #1 had acceptable temp swings (for a non-PID controller), except it ran much hotter than the 225 set point.
Test #2 had really big temp swings, but at least the average was around 225.
Test #4 was the worst - big temp swings and much lower average temperatures.
The other thing you can see is how often the grill cycled during the 30-minute period. With the air gap mod installed, there were more cycles with less of a temp swing. With the mod removed, there were fewer cycles and much larger temp swings.
In actual real world cooking experience, I've been usually running with the scenario I used in Test #3. I've been very happy with the results and honestly, I'd be perfectly happy without my new controller. But I am going to enjoy having many more temperature set points. The big gap between 250 and 300 degrees on the dial has driven me a little crazy on a couple of cooks.
When I post my controller upgrade thread, I will add similar graphs to show the performance difference. Spoiler alert: the graphs are a lot tighter with the PID controller. That shouldn't be any surprise.
If anyone has any questions, I will try my best to answer.
