Motorcycle track pics

Some evening light shots at my local motorcycle track. I experimented with some really tight crops like in image 4 and was happy with the results. As I'm trying to improve any tips or pointers are appreciated. All taken with the Canon 100-400 L.
1.

Nice panning shots.

awesome shots, makes me want to ride but the rain does not allow

Great composition on #4. #8 is my favorite. Nice images shooter.

4 came out nicely. It's hard to get a tight shot cutting a lot out without the photo looking off or just not well composed. But that is one of the few I've seen that has a nicely balanced crop to it that really makes it work. Hard shot to get right, well done.