it seems that a chapter is missing on the differential ... if not, it looks good
You're right, I didn't notice!
Here's a quick rundown on setting up the diff in GTL in particular:
1) Power - the amount of lock of the diff when you apply throttle. How much you set this up depends on the car and type of corner. For instance with a RWD car that has higher grip levels, it helps to run lower lock, so you can avoid having understeer and snap oversteer under acceleration, and it also helps going smoother through faster corners. A higher lock helps with low grip cars and exits out of slower corners, but may produce understeer and/or snap oversteer if you overdo it.
With FWD, because you set those up for a lot more oversteer than normal, you tend to run much higher Power lock, to let the front wheels pull the car forward without much wheelspin. It still has to be modulated with the pedal and not just floored before the weight transfer from front to back is complete.
2) Coast - the amount of lock of the diff under deceleration (throttle lift up and braking). You control how much and how quick the car rotates when you decelerate, thus managing the corner entry. This really is down to personal preference and the balance of the car. Some cars require a lot of Coast lock because the moment you lift up they tend to rotate rapidly. That is very much a function of engine braking and the wheelbase length, as well as weight distribution. With cars that have a natural tendency to understeer, reducing Coast can help a lot.
3) Preload - the amount of 100% lock until a certain threshold is reached under acceleration or deceleration, after which you gradually switch towards the levels of lock by the Power and Coast settings. What this helps with is having some constant lock when the car is rolling on its own, which can make it more stable in the middle of corners, especially longer corners. It's basically a fine tuning parameter that can give you some additional stability at the expense of having reduced rotation rates in the transition between acceleration and braking. I rarely use more than the minimum with this.
I hope this helps.
