Here are some other free games you might like:
The 4x4 Evolution Revival Project is a single and multiplayer on and off road game with no boundaries. You can drive anywhere, and create anything.
State of the art oldschool anti-gravity racing with modding support.
A japanese series of F-Zero like anti-gravity racing games. Rather obscure but technically impressive for the time.
I recommend taking a look at AceSpeeder 2:
AceSpeeder 2 Origin (Same game, different tracks)
There also is AceSpeeder 3 which is a Unity port of the game. Additionally, it is available on Android. However, I can not recommend it since the graphics aren't as nice and the boosting is gone.
There also are OverDrive, AceSpeeder! and AceSpeeder! Remix which are precursors of the games mentioned above. Only try those if you still have an old Windows XP machine standing around as they do not work on newer versions of Windows.