There are many aspects to tuning a car and what makes it even harder that it should, is that there is not one correct set up. What is gold to one racer, might be rubbish to the other. There are many settings to mess with, and honestly you can make your car worse than it would be in stock, if you don’t know what you are changing. So it’s a good thing that you are reading this!
The last tab in your tuning steps is the differentials and this can be a tricky one to understand.
Things were simpler back then
To better understand what differentials do, lets take a quick trip to the past. Things were simpler back then. They came up with simple solutions, to simple problems and continued building on top of that to make awesome things! The video bellow describes, in a rather cool old school fashion, what problem the differential solves, and how.
So, when driving around corners, the outside wheel travels further than the inside wheel but must complete the turn in the same time. So it has to rotate faster. The differential allows for the wheels to rotate at different speeds, but still be able to drive the car forwards, without breaking traction.
Differentials are only used at sets of wheels that supply “drive”. This means that front wheel drive cars have a differential at the front. Likewise, rear wheel drive cars have a differential at the rear. For all wheel drive cars though, you have differentials at the front and the rear and an additional one in the middle, that allow you to decide how much power goes to each set.
To recap, differentials only effect the way power is assigned to the drive wheels during turning. The lower value, the more freely and Independent the wheels will push the car.
Acceleration 6 Deceleration
Differentials are smarter than this. You can set the amount they lock, depending on where you are on the corner. This basically translates to being on the throttle or off it. So you can set the settings of the differential one way, for when you are entering the corner, and an other way for when you are exiting it!
When entering a corner, you will probably be off the throttle. At this point the setting for deceleration apply. Setting it to 0 will allow the wheels to turn freely and the car will be able to turn more tightly. Note that shifting gears at this point, most probably will unsettle the car too much, and send you spinning.
On the other hand, if you set this to 100%, both wheels will turn at the same rate, forcing the outside wheel to drag on the track. On top of this, if you downshift with this setting, both wheels will more or less lock up, practically giving the same effect as pulling the handbrake!
A lower value is preferable here, but it mostly depends on your driving style. Increase this value, to straighten up the car and increase under steer while entering the turn. A lower value will decrease under steer and allow for tighter corners, without loosing grip.
When exiting a corner, you will be on the throttle and for this, you will need to adjust the acceleration settings of the differential. A fully locked differential, will lock the wheels to the same rotations. This will often lead to oversteer, where the back of the car slides away. You’ll need to be very gentle with the throttle to avoid this.
Contrarily, a loose differential will send more power to the wheel with less grip sacrificing acceleration to a more stable exit.
Depending on your drivings style, the type of track you will be racing and how gentle you can be with the throttle, you’ll need to set the differential accordingly.
Increase differential, increase oversteer while exiting corners. If you have too much oversteer, and need to correct the car while exiting corners, try lowering the differential.