Had mine dumped just over the rear axle since 2013, its a 5in flo-pro without the last section on. No soot on the truck and I haven't been turned away from the track. Drone isn't that bad either.
Mine is a 5" FloPro also. I thought about just taking the last piece off but wasn't sure if that angle would cause a problem or if it needed to be pointed more towards the ground . Could you post a pic of yours please?