Re: Getting more hp out of the Fireblade motor
...and torque is dependant on (among others) average cylinder pressure. That is influenced by how much (well-mixed) fuel/air mixture you can get into the cylinder before the inlet ports close, how much energy there is in the fuel, how effective the combustion process is, and that can depend on turbulence, ignition energy, flame speed, squish area configuration, detonation avoidance, effectiveness of scavenging, to name just a few.
But to answer the question that I guess you are really asking, I think the reason why more modern stuff gets more hp per litre is due to better fuel atomisation, higher compression ratios and better combustion chamber design. Plus better materials that allow higher rpm.
Peak hp is only one parameter, and not the complete story. what we also need is a decent spread of torque over a rpm range that suits a 6-speed gearbox. I don't think anyone wants to go back to micro power bands and 24-speed gearboxes.