I want to do 2 9lb buts for my sons birthday next week (turbo method). The last one I did took about 1.5 hours per pound. We are wanting to eat about 5. Can I still plan on 1.5 hours per pound while cooking 2 butts at once. Or should I plan on them taking longer. I guess to be safe I could start early and use the FTC method when they are done. Any help is greatly appreciated.