The 15+ Hp was reported on a 790 America/Speedmaster.

The gain was less on the 865. My BA -02 was dynoed 10 hp+ when I put the Thunderbikes pipes on but that was not from scratch, it was already modified with 'no snorkels', 'UNI-filter', etc
Hasse

Hasse TBA -02 Pre-Fire Cardinal Red, Wiseco 904, Thunderbike pipes, Freak