I will try to keep track of how much backpressure these items contribute, and how that relates to the noise level. Today I put a pressure gauge on the exhaust system, tapped into the EGR port downstream from the front header bank. That will give some idea of the total system backpressure.
The baseline system is TOG headers, 3 inch CAT, 3 inch Borla muffler as resonator, and 3 inch Magnaflow tailpipe muffler, all mandrel bent tubing. At WOT, the maximum pressure reading was 4 to 5 psi and stayed there for much of the powerband.
So the next step is to remove the Magnaflow muffler and do a retest, at the risk of annoying the neighbors.
