So you are serious about drone racing? You will have to time each lap and work on your game to improve your piloting skills. You could always build your own drone lap timer with Arduino to track your laps. DIY Machines has shared a guide for that on Instructables.
This is a 3D printed automatic drone lap timer with an ultrasonic sensor that starts a timer when your drone takes off. When it returns, lap time is displayed to you. The 3D files and further tips are available here.