I was practising for a Yamaha organised race which is up this weekend. Was spending some time practising.
Its a race for stock class R15s. You cant remove anything, not even lights. The R15 can be stripped to make it another 10kgss lighter, it will be more fun then
With the power upgrade, bigger set of shods shpould give your R15 better traction. Michelin pilot 90/90 upfront and 120/80 rear should improve your traction.