How can I smoothly increase the rpm of an engine, my engine in mind is the vivace i3 engine to increase to 20k rpm, when I say smoothly I mean when the power scales with it too, I'm not sure if I have to change the torque values and if I do I don't know what I would have to put them at.
You'd have to both edit the maxRPM value in jbeam as well as edit/expand to torque curve values to make a curve that extends to give reasonable more up and 20k rpm. This calculator can help finding the values to get a torque curve you want: https://www.beamng.com/threads/torque-curve-calculator.84767/