I have a project made on 4.5, that uses AddRelativeForce with a value of 42 upwards on a gameobject. For various reasons I'm backporting the project to 4.3, and the gameobject now doesn't even lift off the ground; I have to use values around 2000 to get the gameobject to lift the same height as in 4.5. I know that AddRelativeForce doesn't exist in 4.3 so I wrote an extension function that, in theory, mimics AddRelativeForce. I just don't understand the huge difference in impulse force needed in the old version. What am I missing here?