I'll be frank here bro, you need to work out on your focus. I liked your 3rd pic (2nd R32 shot) but the car is pretty blurred. And also the karts on the last picture, they're blurred to. Also your compositions; you need to apply certain rules such as the rule of thirds.
It would be a great help to your photography skills if you drop by a tutorial, such as gtsomething's. I'm not trying to insult you or anything, it's just constructive criticism. I'm looking forward to seeing your images after polishing your photography skills. 👍