What exhaust to run to reduce back pressure.
I have a D1-SC seeing 8# with a cutout open. Before the cutout I was seeing less boost and 10psi of backpressure on a exhaust pressure gage. I am running Mac headers, ORP Y pipe and a 3" Flowmaster cat back with a "bypass" pipe between the inlet and outlet of the muffler. Before the cutout I made 522/486 now with the cutout open made 561/494.
Any advice on what system to run so I enjoy good flow and sound is great. Willing to redo the system from the exhaust port back to get both.


