From what ive read stg 1 filter replaces your standard filter and will give minimumal if no top end performance but more mid range and better off the throttle response, where all stg 2 with replaces the right hand side of the air filter box with a filter allows more air in which gives more bhp through out the rev range, more torque, better throttle repsonse, etc.

Also if your going to the track think about removing extras like pillion pegs etc that will weigh the bike down. Also once on the track you can drop the tyre pressures a bit to allow for more grip on the track.

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Plough on