Step 1: Pick a car that is fully tuned and is good for the track you will choose.
Step 2: Choose a track you car is good at. If your car has good handling pick something like the Dirt track or Volcano Sprint. If the top speed is very high choose something like Around the World.
Step 3: Go to the race hub and start a time trial. Try 10 laps or atleast 3 laps at a time.
Step 4: Use a Crowbar or hit your car against the wall on the first lap to reduce the ammount of parts. Less parts = more speed.
Step 5: Note that the game only sees the “Best Lap TIme”, not the entire race.