I’m also interested in what others have to say, right or wrong.
Anyways, I tried 5 configurations last night in the Ford Formula car.
Accel/Decel
- 0%/0%
- 100%/0%
- 0%/100%
- 100%/100%
- 70%/50% - Default?!?
At 0%, the car tended to over-rotate but still driveable.
At 100%, I felt resistance to rotate but also quite driveable.
I quite liked the default setting of 70/50.
I think at low diff settings, the loss of traction comes from inside tire losing grip and the effect of slide tended to be long (as in large swings of the back end). At high settings, the loss of traction would come from outside tire losing grip but the effect of slide could be more easily controlled through fine brake/throttle adjustments.
The entire range of the differential is useable but low setting seem to require precise inputs and high settings being more forgiving.
So I’m no Forza Driving expert but there seems to be some confusion here on basic driving dynamics. I don’t know exactly how Forza takes these into account but here are a few thoughts.
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The deceleration on your rear differential is how quickly the diff will lock on deceleration (off throttle). The closer this number is to 0, the less likely the rear will lock and therefore, the less oversteer you will have when entering a corner. I typically start at about 15% and sometimes (Caterham 500) I run it as low as 2%. Higher numbers cause more oversteer, this is a fact.
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Trail Braking is a real thing that actual racers use! I’ve never raced cars but I do race motorcycles. I tend to drive Forza the same way I ride my bike and my technique involves quite a bit of trail braking and high corner speeds. If you drive speed cars, square off the corners, and point and shoot, then braking in a corner is not as important, for me, it’s one of the most important things I tune for. And how the hell do you get around Laguna Seca or Lime Rock without trail braking?
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I’ve been experimenting with putting more brake bias toward the rear, but again, with high corner speed, stability in the corner is more important than overall brake power. I typically start my builds with about 52% front brake bias. I have builds as low as 48% and I think my Caterham 500 is all the way at 60% but that tune needs some more tweaking.
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I’ve started using Lime Rock to tune for off throttle (transitional) oversteer, I like short laps for tuning and it provides a good mix of trail braking and mid corner braking in descending radius corners.
Fixed that for you. You had it written correctly for accell but backwards for decel.
The way you have to look at decel is the exact opposite as the accell because it is doing the same exact thing as accell but in reverse.
accell -
100% = locked/solid axle/no difference in inner outer tyre - More oversteer
0% = free axles allowed maxium difference between inner and outer tyres - Less oversteer
^ keeping that very simple i know there are other factors.
Decel
100% = locked axles - more understeer
0% = free axles allowed move independently from inner and outter - more oversteer
the less difference there is between inner and outer wheel speeds the more the car is going to want to continue to go straight, however a point i can understand why people say more oversteer because at a point when you are trying to turn with 100% rear decel the car may eventually want to snap if you dive into a corner too hard as the diff is not allowing any difference between inner and outer tyres. However the more you allow the difference in speed in tyres (closer to 0) the more a car is going to want to rotate because the outside tyre is allowed more freedom, this (more commonly) wants to spin the car around, by simple newton theory objects in motion tend to stay in motion.
This is why cars with very low diffs tend to be faster, but require much more throttle modulation. The car rotates very quickly making the time spent off throttle minimal, but they are also very difficult to drive if you tend to coast through corners rather than getting directly back on the throttle. This also can make sweepers much more difficult to navigate because you may not be able to stay on the throttle enough to keep the car from over rotating (especially with a pad) due to the limitations of grip in the tyres.
Try this: whatever the front/rear weight distribution ratio on the car youre tuning is, subtract that number from 100 and set that as your brake bias.
Example: front engine, rear drive car with a 51% weight ratio. Set your brake bias to 49%. Personally i use 150% for my brake pressure.
This is what ive used since forza 3 with consistent results.