One thing MTM2 doesn't get enough credit for is its physics engine. Consider that it's a racing game made in 1998, when some well regarded simulators still didn't allow for cars to leave the ground, and yet its trucks bounce, roll, and interact with the environment with better fidelity than even a few modern games can muster. Beyond that, it actually uses a modest representation of center of gravity (COG) to dictate how trucks handle, and it can be manipulated to create different effects.
The COG is determined by where your wheels and axles line up relative to the XYZ center of any specific truck, i.e. the 0,0,0 baseline that all of the numbers in a .TRK reference back to. For most trucks, the placement of these items is controlled by the XYZ center of the body model, assuming the goal is to visually match the shock locations as well as give the truck a desired ride height. Lowering the model (Y direction) and wheels moves the COG up (i.e. from the bottom of the truck body up to the door or window), moving the model backwards (Z direction) will place the COG more forwards.
The stock MTM2 trucks, and as such, most custom trucks, use a COG that is centered in all dimensions, creating a fairly neutral handling that is not necessarily realistic but pairs well with the standard circuit and rally racing of the game. Weight transfer on these trucks is slightly backwards from reality, in fact, where acceleration will cause the nose to dip slightly, and the trucks lean into turns rather than out of them. "Real Truck Suspension" (RTS) trucks use a COG that has been raised significantly, providing a more correct visual, where the weight transfer under acceleration, braking, and turning follows what you would expect, but it has the downside of causing significant understeer, not to mention that most truck makers who did this exaggerated it to make traction rolling a risk, and in doing so made them impossible to drive. Moving the COG lower makes the the truck more responsive but also more prone to oversteer, and also causes the truck to exaggerate the incorrect weight transfer visuals.
Moving the COG fore and aft has similar effects. Moving it over the front wheels makes the back light, inducing oversteer, and moving it over the back wheels induces understeer. I have not played with left/right dynamics, but they probably have limited use unless someone wanted to start an oval track racing league.
The good news is, you can combine the vertical and horizontal changes to achieve a neutral tuning that also transfers weight properly - a truck with a higher but more forward COG will lean properly, but still turn sharply (as sharply as a monster truck can). The bad news is, it's easy to overdo it in any one direction - there's the RTS trucks I mentioned above, and you can create trucks that wheelie on demand or stoppie at the touch of the brake. But, with some care, and deft touch, you can actually make a truck that behaves reasonably and looks the part, too.
So now that I've established all that, time to go back to my SS and MTEG trucks and play around some more - the effects I want are closer at hand than I could have hoped.
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