Depends if you go full blown clutch kit(machined primary and secondary) or just a basic kit that replaces weights and springs in your primary. The basic kit helps the belt bite more against sheaves(allowing the ability to turn bigger tires without belt slippage) and weights change your stall(rpm at which your bike begins actually moving) and adjust how much long a bike stays in a higher rpm gear. Full clutch kits does the whole Thing and it can be set up exactly how you want(stall, how long to hold gear out, belt grip etc.) Alot of racing people go with the full clutch kit due to it gets you a ton of low end but doesnt take away your high end either. basic kits usually take away top end. annnnddd yea thats about it lol