so are these part of the "most did not come out well" or are these the few keepers?
These look good to me in terms of panning. Considering it's at a drag strip they backgrounds are about as good as could be expected...

So if you're just looking for panning tips, PRACTICE PRACTICE PRACTICE. It's definitely a skill. Some people never get it, some get it right away, some learn with time. It's all in how you pan. You need to match the camera's direction with that of the subject. Try shutter speeds of 1/90th ~ 1/125th to help a bit with getting only one direction of blur. Then slow the shutter speed down as you get better. Also go out and shoot random cars on the street until you get better at it. This way you can practice on stuff you don't care about and be more confident when you're shooting something you want to nail.

Not bad at all for a first attempt IMHO.

Ben