Looking for cure for a very loud ITA Miata. This car is noticably louder than any other Miata on the track and depending on conditions I have had sound readings from the high 90's to 104. I installed a new muffler between the last two events without any noticable difference.

We have changed the muffler location to see if this would make a difference without any noticable effect.

Looking for a non-restrictive muffler that will quiet this car down