There are two possible flights DFW-HNL, one at 11:15 and one at 1:20. I'm assuming you have the first one. An hour and forty minutes is gobs of time. It will take at most 5 minutes to get from your arrival gate to the skytrain, 10 minutes to get to the correct terminal, and another 5 minutes to get from skytrain to your departure gate. If your inbound is on time and your outbound begins boarding 45 minutes early, you will still have a half hour to kill at the outbound gate. Use this time to pick up some decent food to take onto the plane (unless you are in F). It is a long flight to find out that there are a lot of hungry people on board and not enough BOB.