All good pics. Sharp and clean.
Like 1 and 3 in particular.
A little cropping (on 1 and 3) might help – might work well in more of panoroma form.
A touch more saturation and contrast may help 1.
Great set.
#3 would be the favourite followed by #1
#3 Gives the impression that the racing was racing was close. Well captured.
#1 The lads really hanging off the bike with knee and almost his elbow on the track.