>>28703053
Suzuki's 1.4L k14c i4 for their cheap-ish swift sport makes ~160 with just an ECU flash and can somewhat reliably (for around 60-90k miles) push out 200+ with basic mods. 100-130hp one liter twin seems very feasible to me, especially if we consider that engineering can smuggle a solid chunk of power in the higher revs and hide them behind emission compliant tune.
>>28703057
Power = Torque x RPM, routinely revving to 7k at each stoplight seems like a funny thing to do.