Originally Posted by ChrisSlicks

The car's ideal water temp is right around the boiling point of 210F, the electric fan doesn't even kick on until 213F. Anything under 230F is fine, unfortunately it's pretty easy to get the water temp to 250F on track on a hot day with the stock radiator. Once you see it marching up just back off for a lap and the temp will come down fairly quickly. Big ass radiator is next on my list.