Physics discussion thread

In order to add some clarification for future readers:
Engine braking exerts additional braking force on the rear tires, most noticeable when downshifting when the car is in gear. Engine braking can be used for additional lap time on tracks that feature hard breaking zones, like Monza T1. It can exert additional braking force more than the brakes alone.

Reducing engine braking and moving brake bias to the rear is a viable option at the cost of overall braking force (especially at the start of the braking zone and brake temperature.

The sensation of the rear sliding MORE than the front (OS), is always due to F/R traction imbalance. This sensation can be caused either by a natural imbalance favoring the fronts, most noticeable if the rear of the car wants to step out when off throttle OR due to changes in traction balance when on-throttle as the driver is asking for long acceleration from the rear tires when grip is already being used laterally.

That “floaty” feeling appears to me to be the consequence of two things. The car being in a “neutral steer” situation where the front and rear are both sliding at the same time, and the effect of pneumatic trail where steering forces are more muted in a slide. Neutral steer is almost the optimal situation of a car to be in as it means maximum grip is being extracted and the car is completely balanced. The self aligning torque drop off due to the pneumatic trail being shortened in a slide is one of the features of the SETA tire model. It is a real life affect.

Reducing clutch plates from 6 to 4 reduces locking of both coast and power by 33%. Adding preload increases the minimum unlocking of the differential. Meaning there is more lock at lower forces and less lock when there are more wheel rotational demands.

Factoring in the analysis from @DaveLew, it suggests that other sims allow for only 1.0% to 1.5% unlocking which manifests itself as a more controllable car under most situations that snap when too much is sought from the tires. This is a realistic danger with this amount of locking. 3rd parties have also verified that other sims reduce engine torque curves for the benefit of easier throttle car control. There are some in the sim racing community that feel this is more realistic.

The solutions posed on this thread however suggest an overall decrease in locking for more realistic behavior.