Sorry to hear about this. We have been fighting this kind of thing forever at our local dragstrip here in Portland. Because of the noise restrictions we have to run mufflers and have a 10pm curfew (103 dB @ 50' limit). Typical crap, a track built in the 50's being complained about by people who moved into houses built in the 70's, that is also in an industrial area and in the airport's flight path. At the houses in question, a city bus driving by is noisier, but they claim it's because of the repeated noise that it annoys them. We used to have major nitro events at the track. The city used to grant sound limit exceptions for Indy car events, but since that series has tanked they don't run here any more. As a result we were able to run a single big drag race each year, but this year the city dragged its feet too long (and they own the track as well), and we did not get a big event from NHRA.