Here is a great Forza Motorsport 2 Suspension Calculator.

Just plug in your cars drive and engine placement, weight distribution and total weight. Select the type of spring feel you and and press calculate.

This gives you a great baseline for tuning your car’s suspension. It is not the end-all setup, it is just a much better starting point than the default setups. You’ll want to tweak the final settings to your liking once you get a feel for things.

The setups from the calc produce a bit of an oversteering car, which some people prefer. I like understeer myself, so I simply adjusted the swaybars to suit, and most of the rest of the setup was great.

My cars are much smoother and easier to control than with the default values or just trying to tweak them myself.