I have come up with some pretty simple equations about the power produced by an engine and how the torque, rpm, and acceleration come into play with different weight vehicles, transmission gears, axle gears, tire diameters, etc. The problem I have is how to graph them. I have seen many free simple graphing programs, but they don't seem to do what I want them to. I want to input a set of points for the engine torque (rpm and torque graph) and have it do a estimation to find what it thinks the rest of the points should be. Then I need to be able to use that equation in other equations, and that equation in other equations. Does anybody know of some freeware graphing programs that will allow this? Or will a Voyage 200 handle it?