I was reading the description for acceleration and deceleration settings for a race differential on a rear-wheel drive car and I’m wondering if the description is wrong. Just want to get some clarification on how I understand things here.
It’s understood that the differential controls how much a difference is allowed between the inside and outside tire rotational speeds. The description says: “Increasing the differential setting makes the differential tighten harder and more quickly under acceleration. On rear differentials, increasing the Acceleration setting can increase oversteer in rear- and all-wheel-drive cars”. This seems backwards to me.
If the outside wheel is turning more quickly than the inside wheel, then that is a situation where I would expect oversteer in a rear-wheel drive car because the back end would want to swing around. If the differential tightens more quickly though, there is less of a difference allowed the inside and outside tire rotational speeds. So to me, it would seem like the less of a difference you allow between the inside and outside tire rotational speeds (i.e., increasing the acceleration) the LESS oversteer you would have.
its a video game … nothing in this game works the same way it will in real life … there are pages upon pages of things that arent exactly correct , in my opinion ignore words ingame and tune it by feel if it feels better keep going that direction .
@manteomax that video is great if the game only relied on the “open” style carrier or the famous 1 wheel peel , forza calls it a race diff or a posi unit . in real life the more shims you put in a posi the more the wheels lock together and if you cram enough in there it will act as a spool (spools are mainly used in drag racing ) . but again forza is a game that is not entirely based on real car physics
simply put the higher the percent the more lock between the wheels… 0 is open so if you mash the throttle through a corner the inside wheel will spin and bleed of speed so you want to fine tune it… i normally try to keep is above 50% and no higher then 75%… the higher the % on deceleration will cause more lift of oversteer
I would say ScalyPineapple is correct on this one.
Diff set to 0/0 take moderately powered car, and you start making circles with 1 tire smoking.
Diff set to 100/100 that same car either wont have power to spin those rear tires, or you start making donuts…
Too little % and the inner tyre will spin, making lesser grip as only the outer wheel is keeping traction, if the outer tyre then gets too hot, it will still oversteer (On 4WD or RWD that is) though generally the car will somewhat keep on its line and just spin all the power you’re trying to put down away through the inner wheel. If the % is too high then the outer tyre will want to spin first, making a quite sudden snap of oversteer happen, I find its very dependant on the type of tyre and width of tyre, perhaps even the weight of the vehicle too. The more grip, the higher the % I find myself going.
More lock: Less wheelspin, but abrupt oversteer if torque is excessive. Safer but requires finesse.
Less lock: More wheelspin, but car becomes more manageable. Better in dry conditions.
Decel:
More lock: Less oversteer when off-throttle, but abrupt lift-off will cause spins. Don’t increase too much or the car won’t turn.
Less lock: More oversteer when off-throttle, which makes the car unstable. Throttle should be used to balance the car.
The way I tune is like this: front engine and RWD uses high accel lock and low decel lock, mid or rear engine and RWD is the opposite. FWD requires low accel lock and somewhat high decel lock but not too much.
On AWD cars I use low accel lock and open decel (0%) in the front because you want the front differential to behave as close to the front axle of an RWD car as possible, but a small accel lock might be good because if you don’t have any lock you’ll just understeer when exiting corners. This problem can be minimized by moving the split bias towards the rear, though.
Increason the diff lock depends on the other setup slightly. Not as drasticly as it would in real life but here goes…
The more lock you have can cause either understeer or oversteer.
Yes the ourside tire is turning more than the inside tire, Possible results of diff setup:
100 (Locked)
Now depending on the grip of those (and front) tires the result can be -
A. The rear tires maintain grip and resist turning, which will cause understeer
B. The inside rear tire wants to spin at the same rate as outside tire, but due weight shift it loses traction, This leads to all laterial grip needed comes from outside rear tire, which cause…
B1. the inside tire to lose grip ans slightly slide, but the car keeps it neutral handling
B2. The outside tire doesnt have enough grip to put the power down and maintain all of the needed grip toturn the car and therefore brakes loose, which leads to oversteer.
0 (Open)
Too Not enough diff lock could lead to
A. Inside tire losing grip. All power goes to inside tire, so outside tire will hold as it doesnt put any power down anyway. Result “One tire fire”
B. Inside tire losing grip. All power goes to inside tire. Outside tire cannot hold and it loses grip causing oversteer.
Ideal is in between, where the power is distributed near enough evenly that neither of the rear tires dont lose their grip
