I barely passed a test at a local club field with a Sport Jett .50 with red muffler - ran it up in the pits on an 8.8 x something APC pylon prop, and the club noise officer came skedaddling over, telling me to shut down and I had to come over for noise testing. So I said "sure...", and replaced the pylon prop with a 10-6 and opened the needle a half-turn before heading over for a smoky inspection. I barely passed at 95 dB. Then I swapped back and everyone else who wanted to see the Demon go, including the club pres, was happy.
Another good data point. That SJ must have been shrieking with a small pylon prop on it and I won't be at all close to that kind of power or prop speed.
Mark