You are right Mars. I was experimenting with different speeds and ISO trying to find my threshold. I posted some of the blurry images for others to see the cars that were running. I appreciate your input!
What was your exact setup? I take it you were using a 70-200 2.8 L IS? You can get away sometimes with a 1/30 of a second speed, but its going to be one of those lucky ones were things were just perfect and having a monopod does help a lot especially when shooting at the 200mm range. I will shoot anywhere from 1/60-1/250. Just depends on the distance they are from me, the speeds they are traveling, and the direction they are coming at me.
something like this is more or less a high shutterspeed. fast enough to get the cars sharp, but you can still see the tires are spinning and not frozen. It took me a few drift events to get panning down and the past few years i've just been working on trying a few different things to see how they come out.
