Multiple drop-down lists

[Erufailon]

Hello, this is my first post and as you understand I am a total noob, so I need your help and understanding
I want to create a drop-down list for various car competitions with lap times for each car in each competition. For example :

Comp1
driverA carA timeA
driverB carB timeB
driverC carC timeC

Comp2
driverA carA timeA
driverB carB timeB
driverC carC timeC

Now I want to make a drop-down list with the 2 (or more) competitions and when I choose Comp1 to list the drivers by their lap-times and so on, that means the faster driver goes on the top.

Thanks for any help