I have my gear plot. I need to find some way to combine that with the engine's torque curve in order to get the kind of curve Unreal requires. The obvious solution is to use the output of the gear plot as the input of the torque curve.
This is a basic mathematical tool called function composition. The problem is that while the gear plot is a set of linear functions, the torque curve isn't a function at all. So we need to find a function that has roughly the shape of the torque curve we are interested in.