I got the APH "Race" exhaust that Alan was making before the NCCR one and it is NOT quiet. LOL. Its the stainless underbody oval can with a riveted rear section to replace the packing (that blows out every 20 miles...).
Did some dB testing awhile back:
Measured at 5 feet with the SLM app on i-phone
Idle/5k RPM/ WOT rev
Stock complete exhaust 80/94/100
Resonator delete/tips 88/97/106
Open header 102/117/124 and the shop ceiling was dropping dust!
APH Y-pipe 100/111/118
APH Race 90/105/110

https://www.youtube.com/shorts/a2lqBS2gSmk