I don't remember much about the pit but you just want to grind sessions until you get your average finish times lower. I haven't watched your run but generally you want to keep track of your times at each part of the level so you know your pace. Focus on getting good entries to the building and then clutch the ending. You want to maintain as much of your momentum as possible while shooting the targets. Ok I just watched your run and it was clean but you can gain a lot of time by learning how to groundstrafe and even just jumping at first especially at the end of the level. Also the line can still be cleaner, I start my run on the right side of the course and take a straighter angle.