These are the ART pipes:
https://motordyneengineering.com/pro...ng-test-pipes/
I'm with ZontheRocks - since you already purchased the Borla, I'd look into resonated HFCs or the ART pipes for more sound. If you are willing to get rid of the Borla, you could replace it with something more aggressive (Motordyne, FI, Tomei).