It kicked on for the first time (that I know of) this past weekend after a track session, and it seemed to be sucking outside air into the engine compartment.
An interesting thing, there were several other cars including one big 4 door BMW that was blowing my doors off, but he had to come in after about 15 minutes because his water temp got up to around 250 (according to him). Mine never got much above 180 (needle just to the right of the 0) and I ran several 25 minute sessions and also ran more session that day closer together than he did. And still that fan only kicked on a couple times after I parked after my cooldown lap. (Should it be coming on everytime? Now I feel like I have to look it up...)
