2.5in DP vs 3in DP with GIAC software

Awe recommends using a 2.5in DP/TBE vs 3in with the k03 and k04 GIAC software. They show pictures of dyno runs that show the 3in causes a loss in HP and torque. They also claim that it causes a drop in boost pressure, and a loss in throttle response. If somebody could chime with thoughts about this it would be appreciated.

Sent from my SM-G928T using Tapatalk