1) Can you have Cat burn and secondary burn at the same time? After reloading tonight I let STT to raise to 350* before closing the bypass and immediately throttled the back to 1.9 on the air. I normally drop incoming air in increments eventually arriving at a setting of around 1.2, The flame quickly died down with no secondary burn. When I lifted the lid, the CAT had a beautiful red glow. The glowing went on for over an hour and then the secondaries started puffing. After the secondaries kicked in, no more glowing on the CAT. Normally I have no glow on the CAT. 2) Can you feed the CAT to much smoke? 3) Which is more efficient? Secondary or CAT burn? Which would put out the most heat.
If the cat is engaged and not dead it will always activate while secondaries are going. It doesn't have to be glowing red to be active. So, yeah a burn with secondaries is going to put out more heat. Most of us run a cat only "low and slow" burn at the beginning and end of the season. This time of year my secondaries are cranked- which decreases burn times but I need the heat. Any extra gasses the cat can't burn will simply go up the chimney. You'll find this when the cat gets old.
