Post #307...something to consider.
https://986forum.com/forums/diy-project-guides/19770-diy-exhaust-mod-%96-gain-10-hp-16.html
Local muffler shop charged me $20 to weld small plates over the shell holes.
Has a decent growl at idle up to about 2700rpm. 3000rpm and up really howls. No significant drone. Neighbors happy, wife happy, I'm happy.
