The following guide describes how the differential works for most F1 mods available in rFactor 2.
Differential Pump
F1 differentials are of a limited slip-type. This means the level of coupling between the differential input shaft and the rear wheel driveshafts is variable. The differential's level of coupling (or pump as it's shown in rFactor 2) determines how the torque is applied to both drive wheels in relation to one another. At 100%, both drive shafts are effectively locked together, and torque is always applied from the differential to both wheels equally. At 0%, if one wheel should lose traction unequal to the opposite wheel (as if half the car goes onto the grass shoulder), then the differential shifts or "slips" torque away from the wheel with the least amount of traction.
Understand, as this is a mechanical process the differential cannot operate giving great shifts of torque from one wheel or the other. In other words, regardless of the differential-lock setting, both drive wheels will always be getting a great amount of torque in an F1 car. Using a 0% differential pump setting, the shift of torque from the offending wheel is still a minor percentage.
rFactor 2 allows us to fine tune the differential under acceleration and also off the throttle; these adjustments are called power and coast.
[b]Differential Power[/b]
The differential transfers more torque towards the wheel it thinks is the external one during acceleration. Keep in mind that the effect of the differential power only comes into action during corner exit and most importantly, during acceleration. Ideally, it would be tuned so that during acceleration, the exterior wheel pushes more forcing the car to continue on the track without incurring in a spin. If during corner exits while under acceleration the car goes to the outside of the track, you should lower the differential power setting. On the other hand, if the car starts going towards the inside of the curve under acceleration, then you should increase the differential power setting.
[b]Differential Coast[/b]
The differential transfers more torque towards the wheel it thinks is the internal one off the throttle. The differential coast only comes into effect when off the throttle and mostly during corner entry. Ideally, it would be tuned so that when you lift the throttle the car's initial response is to enter the corner in a stable way, not too much to the inside and not too much to the outside. If under turn entry the car goes too much to the inside, then you should increase the differential coast setting. On the other hand, if the car goes too much to the outside, you should decrease the differential coast setting.
Preload
The preload affects how smooth the transition from power to coast occurs. We can think of it like the "differential reflexes". Higher preload values require more torque before the differential shifts from power to coast. On the other hand, if the preload is configure low, then less torque is required before the differential shifts from power to coast. This is usually the last modification done to the differential, you would use it to make the final adjustments. It is recommended to start from a very low setting and work your way up until you feel both the differential power and coast are acting at the ideal time.
Summary
[b]Differential Component[/b]
[b]Adjustment[/b]
[b]Result[/b]
[b]Pump[/b]
High values (>50%)
Both rear wheels would have nearly the same amount of torque as it approaches 100%. Useful at circuits with long straights and few slow corners.
Low values (50%)
Forces the car to go towards the outside of the corner during corner exit under acceleration.
Low values (50%)
Forces the car to go towards the outside of the corner under braking or coasting off-throttle.
Low values (
Janos Magasrevy
SRH Founder and Director