Just asked Cal sport.
They said the Akra full system would be ok as it was developed as a full system on the bike (as long as the stock filter was used). The shortie is different as it was initially a slip on, not developed as part of a full system and then the made the header pipes later, to fit.
They said the Akra full system would be ok as it was developed as a full system on the bike (as long as the stock filter was used). The shortie is different as it was initially a slip on, not developed as part of a full system and then the made the header pipes later, to fit.