dang very intersting reading this I always wondered what the dB limit is. Louder than stock is a very unfare rule because even SRT4 have a rumble to them stock. But if one were to say its a different engine how could they tell you no? My point is if you took a SRT4 motor and put it in lets say a Civic and used a different exhaust like the OEM SRT4 how do they determine if its louder than stock. Is it by motor or type of car? An intake just loudened up my car a good bit, nothing rumbling but its louder. Man if they made ATV's street legal i'd be screwed I think my exhaust is like 102dB at 3,750RPM and when revving I thought someone tested it at 135dB and stock was 86dB. They need a set sound limit for exhaust and at a certain RPM. I know for ATV racing they used to test at 3750RPM for all ATV's and it has to be 102dB or lower at that RPM. The recently changed the rules to 99dB and the RPM they measure it at is by the formula of 306,000 divided by the engine’s stroke why cant they do that with cars? How much are the tickets running for this infraction?