I inquired with Lime Rock Park on their max db level, but do not know how or where within the Park the measurement is taken:
" The normal day to day db level is 83. However, we do have what we call "Test & Tune" days in which there is no db level restriction. Those days are: 4/13, 5/11, 6/15, and 9/28 "
Sounds louder when sitting in either the infield or outfield. For those that have not been to Lime Rock, it is in a very rural area, adjacent to small towns and in a valley, no grandstands, a large portion of the viewing on both the infield and outfield is on the sloping land looking down on the straight and the first 3 corners. Paul Newman drove the Datsun 280ZX & 300 ZX at this track for Bob Sharp, he lived in southwest CT.
This summer the NASCAR Modified race cars ( open wheel ) will have their first race at Lime Rock, running clockwise. The 5/11 " Test & Tune" day mentioned above will include the Modified cars for tire testing etc
http://www.limerock.com/