The Force II system has the resonators, the American Thunder does not.I tried a Borla system without the resonators when I had my ‘11 Challenger R/T (5.7/Auto) and the drone was unbearable. I replaced it with the Mopar/Corsa cat-back system with resonators that eliminated the drone but wasn’t the exact sound I wanted. If I still had that car, I would have gone to the Flowmaster American Thunder system that has resonators.
Where in the system did you have the Flowmasters installed? At the location of the stock mid mufflers? Or at the back where the resonators normally go? Got any audio/video clips? I’m trying to decide on whether to delete my resos.I went with Flow Master series 40 with resonators deleted 3 months ago and love the sound. Nice and healthy on a 2015 RT.