Sound hates turning corners so the 90 Deg bend in the snorkel heavily attenuates the induction roar with the side effect of a small drop in induction efficiency. There is also a kev recommended mod for drilling out the airbox if you want another gain.

Most of the mods give a small to moderate gains but when you put them all together the difference in the machine is just brilliant.

The real nice thing is that if you sell you can put it back to standard for the new owner if that's your agreement. Even drilling out the airbox, if you use the recommended 28mm holes you can plug them with rubber grommets.

Marcus