Now that's interesting, my '28, open (32mm) carbs, Tyga pipes, unknown race cans, 99db at Cadwell yesterday.

94db with the airbox.

Both measured by the same guy in the same manner, i.e. as the ACU say.

Also be aware, not sure about anywhere else but Donington have drive by db sensors around the track, their point of view is sod what the ACU say, the council say the noise limit is the limit, not the limit at 7000rpm measured at the pipe and it's the council who set this stuff.
I got thown off a quiet day running stock pipes.
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