I have that site linked from the front page of the track web site here. BTW, it's cool this AM, clean air and a fantastic 2981 DA. Problem this summer has been that the DA at the airport 10 miles from the track might be 3000 and the track 4500 because it's raining at the airport and not at the track LOL. So it depends on where you get the reading because airdensityonline gets it's data from the closest reporting NWS weather station, NOT the track it's self.
This is what great 3500 DA does to my bitty 300HP 302 car: