I intend on using the standards of Commiefornia to test my exhaust -- not because I will ever live there again or live there currently but because they're just known for over-regulation and being unnecessarily strict so I just decided to use their testing standards to test the decibels of my exhaust. I would be able to determine if my car would be "legal" in this state. May also go out there on a road trip one day.

I'm already planning on changing my exhaust and I wanted to measure the current one before I change it out, then measure the new one.

The problem is, the car is limiting the RPM to 4500 in neutral. I've searched all of the place for this information but can't find it. What I'm wondering is what they do to test decibels in CA (or any state with similar/same situation) when the car limits the RPM below the 75% goal?

Do they move the placement of the microphone or just use 4500? Maybe it depends on how far the limit is from the goal of 75% of the RPM? According to the testing method, I need to rev to 5850 RPM (If I remember correctly that 7800 is redline on the 2012 G37s).

If they do move the mic, where/how far is it moved?