I have talked with several people in both the game and in the forums and I hear a lot about people who do not know how to drift, can tune but can’t drift, can drift but can’t tune, ect. Some of these people have gone to the forums and asked questions and generally get some good help but a good while ago I made a tuning calculator on evening out a car’s suspension to help with the weight roll of the vehicle. This calculator has been tried and tested throughout the different implementations of the Forza series and the base formula has gone back as far as Forza Motorsports 3.
In short, I use this calculator in just about any build I want to do in FH4 and it has worked miracles for me. Between drifting, racing, or even off-road, I have used this as my base for my tuning. Note, this will not go over your alignment, tire pressure, gearing, or anything else, it is set up to give you a balance reading for your Spring Rates, Antiroll Bars, Rebound Stiffness, and your Bump Stiffness. For a more accurate tuning of your vehicle for your likes, the Bump Stiffness is really the only setting that can be changed since the original formula calls for the car to be between 50%-75% of the Rebound Stiffness, which is also calculated for you in the calculator.
Also, there is no change between the English and Metric settings for any of the suspension elements, but, they are also separated for ease of the user. The calculator is set up for very simple users in there are only 4 fields that need to be changed, which is the Min/Max of the Spring Rate of your vehicle, and the Weight distribution of your vehicle. IE if your vehicle is 54% Front, then your two calcs are .54 and .46 which equals 1.0.
If you would like to try this calculator out and see if it helps you with your cars for drifting, the calculator can be found here :
https://forums.forza.net/turn10_postst144582_---UPDATED----Tuning-Calculator-v2.aspx
Any additional information, just get with me on here, or throw me a party invite on XB @ Senistr and if I am available, I will come and give you a hand.