Put a gallon of gas in the truck before you run.
and/or knock off your high gear shift point by 100-200 rpm.
For braking, if you're doing the chasing, when you catch your opponent, stay flat in the gas, and tap-tap-tap on the brake to hold that relationship. If you're being chased, try to use your mirrors to determine who's going to get their first. If you can tell you're going to get there by a fair margin, but you're not sure by how much, you can scrub the brake lightly a little bit as described above to take up a little bit of the room early, and then make the determination later in the run on whether or not to kill some more.
Unrelated -- replace the brake pedal 2-step setup with a brake pressure switch for improved R/T consistency. (see Tech forum)