The burner isn't usually as much the problem as the regulator. My old turkey fryer had an adjustable 10psi regulator on it that would just barely maintain 7 gallons at a boil. I bought a 20psi regulator for it from Bayou Classics and it'll now bring the same amount of wort to a raging boil in under 10 minutes. It's insane! If I read right (and odds of that happening are pretty low), with a regular turkey fryer style burner, a 10psi regulator will run something like 55k BTU. The 20psi one is supposed to be closer to 185k. I may be off some on the numbers, but I know it screams now compared to before.