I was surprised when I first read this on the motorsportreg.com site when registering for the recent SCCA NCM event
"THERE IS NO MUFFLER REQUIREMENT FOR THIS EVENT!!!!!!!!! "
But then the supps stated this
"Sound control will be enforced for this event: The sound meter is located between Turns 3 and 4 on drivers left. The sound limit is 103 dB."
Might have confused people.