I’m trying to understand why the differential settings seem to be all over the place. On RWD cars and Mid RWD cars I’m seeing the open source tunes with very very low acceleration and deceleration settings. Why are my accel numbers so much higher on cars without any noticeable negative effects. Is it just driving style or preference or is their an actual method behind it. Deceleration settings I understand and adjust them as needed to control lift off oversteer but why are the numbers so varied? Seeing MR cars with the decl as low as 15 and others in the 40’s and 50’s?
Because most “tuners” have no idea of how to use a differential. The pre-sets from Turn-10 gives a hint about how it should be used, just check up some pre-tuned cars and you will see high values.
As a basic, 50-55% is a moderate setting for a rear-wheel driven street car, racecars mostly likes a bit higher settings, the 75% std setting might be a bit high though. Too high and the car starts to understeer, too low and you get too much wheelspin.
Basickly I prefer using the about same settings for acc/dec a bit depending on what car…
FWD`s is another story, 25-35% before they loose grip
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You have to keep in mind that this is not real life. What works IRL may not be close in Forza world. I have some cars with ridiculously high rear diff that work well, some with ridiculously low rear diff that work well. It doesn’t matter if some “tuners”, as you say, know about diff, it matters if they know about Forza 5 diff. Experiment with extreme highs and lows on all cars when tuning…what feels really good at “normal rates” will be a second slower than something abnormal in some cases.
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Yeah, they can “work well” but would work better if you improved the diff-settings. Forza is not that much unlike real life, but this is also a lot about driving-style and vehicle.
I should have clarified, by “work well” I meant top 10-20 tunes but dang, I guess I better go change all of my tunes 
I crank mine way up usually in the 80-90 range
That`s ok for a drift-car going sideways with full wheelspin but ruins turn-in for a roadracer
I’m using RWD not sure if that makes a difference, it starts at 75 so going up to 85 isn’t that drastic… I do find that I need to adjust other things to improve turn in but I’ve found with a higher diff setting I can hold more speed and throttle through long corners without losing traction.
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Off course this is for RWD only (+ RW-settings on 4WD`s). Yeah, racediffs are pre-set to a 75% brakeforce, that might be ok on some pure racecars with lot of forcedown & grip but on a hotted up street-/sportscar the diff should be adjusted a bit lower to avoid understeer. 56-58% seems to be the magic borderline between over-/understeer on most RWD-cars.
85% is way too tight if you want a good turn-in response, the diff is allmost locked. Good for drifting but not for racing…
Worm; values like 25% is too low. The diff will act as an open diff with values that low. 45-60% is my 2c, or should I say 55-60
Torrider; low diff-settins that allow one wheel (inner wheel that is) to spin is a misunderstanding. To get the best out of the enegine and to avoid wheelspin the diff needs to be tighten up to some 50+ and so on.
JKS 9; a “posi” and a limited slip is the same thing, Limited-slip is the generic term, each manufacture has their own specific name. GM = Posi-traction, Ford = Traction Lock, Chrysler = Sure-grip, DANA = Trac-Lok/Power-Lok. I gave up trying to get my students to use the correct name, to them any limited slip is a “posi”.
What you say about winter-driving tells me you are not a scandinavian like me. The last one you describe is an open diff. You will have a hard time selling cars with open diffs up in the north, they are useless in wintertime.
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Want to bet?
There is a reason you guys continue to struggle, and it comes from a lot of people, it’s because you don’t listen. It’s fine to experiment and enjoy the game the way you want to but if you are going to tell me I am wrong when I’ve used the same basic differential settings for 5 years I don’t really like it. You continue to argue when people, not just myself, keep cranking out great car after great car and giving you advice TO HELP YOU OUT. I can put the same tune on virtually every car in the game based on it’s drivetrain and it will feel great and if the build is right go fast. Forza still operates under the same generic, one size fits all suspension system (with the exception of FWD which is bugged) that it always has with minor tweaks here and there. Roll bars and camber have changed, nothing else in this game has since the beginning of Forza. Fine tuning that base setting may take off a few tenths, and maybe a half second based on the gearing but nearly everything has values based on a % of the bar that are the same. A 3300 lb car is going to be stiffer than a 2300 lb car but it’s going to be in the same area on the bar.
I would bet an absolute ton of money that if I went to Clay, Lee, TN Eagle, Loco, DUST2DEATH, Raceboy, Craviator, and anyone you think of we all pretty much build and tune cars the same exact way. These people rarely, if ever, crank out a bad car.
Just listen to what people say when they are trying to help out. I don’t post to run anyone in the wrong direction.
If you want to prove me wrong then tune a better car, I have no other way of saying it. I’ll even run it for you and give you honest feedback, and don’t come back with that driving style stuff either.
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Sorry for the typo,…but NO. You can NOT just slap ANY diff setting on a car and expect it to work.
If I slapped some of the diff values people have mentioned in this thread, then my cars would handle like crap,…or at the very least I’d have to retune my suspension balance to compensate for the over/understeer differences.
If you tune a car to handle well by matching all of the other variables of the tune, and then start adding or dropping 10% to the diff settings, the car will NOT handle as well as it did. It surely wont handle the same.
A well balanced Ruf CTR 2, for example, can be wildly unstable with even small changes to the diff settings.
However, can you choose to use predetermined diff values and then tune the rest of the car around those values,…then YES, absolutely.
My point is that diff settings are only one ingredient of the recipe that makes up a complete tune.
+1 to this. I put pretty much the exact same starting build/TUNE on all my cars and tweak abit here and there. Run all my own builds and tunes and I run top 10s-20s-30s in various classes (A-P). The exact same builds/tunes from Froza 3 and 4. People really make the tuning harder than it is.
When I try out tunes out from Worm or Crav or any of the guys you see in the top 50 they magically feel like a tune I would do and are within tenths + or - what I run.
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See this is why I’m asking. I have seen very low numbers and I have tried them out as well but it seems to feel and drive the same.
Depending on how much power the car has I start between 55-65% and adjust until I find a good balance. Highest I’ve ever set a RWD car was something like 78%.
Any ideas on awd? Also does anyone find the 1.5 diff useful.
It depends on the traction and power of a vehicle, weight distribution, etc. If the rear diff is at a higher percentage, the rate that each wheel spins is closer, if you go around a corner and put down the power, your more likely to oversteer and spin out with higher diff setting, the less the percentage, the less both wheels will spin together causing a car to go sideways. The lower the setting will cause one wheel to spin while the other maintains traction, keeping the rear end from kicking out sideways, this also causes more wheel spin for one wheel, while not having as much traction under acceleration on a straight.
There is usually a fine line between traction and oversteer, too much diff, means more oversteer, you will need to have a light touch on the accelerator to maintain control, too little and you will have less drive out of a corner, and less acceleration, but more control in the corner no matter how much throttle.
You will see a 10% dif setting on RWD cars with higher power and less traction, and a higher setting on RWD cars that have more traction, it really depends on makes and models, distribution of weight, engine power, suspension settings, etc.
As a better example, a positive rear end on a car, when driven in snow, will be almost undriveable as both wheels spin together, causing the rear end to slide everwhere. A limited slip on the same car in the snow will have 1 wheel spinning while the other does not, keeping you in a straight line, under control. 100% dif equals positive rear end, 0% equals limited slip rear end. Tune for your desired result.
The decel settings control the rate the wheels spin while downshifting, again the higher the setting the more both wheels will grab the pavement under decel, under hard downshifting a wheel can and will lock up a little, if both rear wheels lock up, you get the e-brake effect causing the rear end to come around on you, the less the setting, the more likely only 1 wheel locks up, keeping the other wheel rolling to help maintaining control, however too little percentage on this will always cause one wheel to lock up, and that makes it handle erratically, there is a middle ground here, you need to play around with it to see what works, you want enough decel to help keep traction under downshift, but not too much to lock up the rear end, and not too little to have one wheel always locking up.
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JKS is correct. You others all have it wrong. The reason for the low accell dif numbers in these tunes is to allow the left and right tire to spin at different speeds to allow for better powering through and out of corners. The low dif setting in the decel is to allow for the wheels to spin while not on throttle. The low numbers allows the car to rotste its rear quicker to finish the turn quicker to start acelerating out sooner,
On AWD, the more percentage on the front diff will cause understeer while accelerating in a corner.
I believe I may have figured out what the difference is between the higher numbers and the lower acceleration numbers. It seems to be a lot smoother going back to throttle through the trigger. With the higher diff setting I was feeling a slightly higher vibration through the trigger but not quite breaking the tires loose. After messing around with more than a few cars in the garage I started to notice the vibration would reduce back to the engine vibration through the trigger. The car would still behave the same on throttle exit but the trigger was smoother. Start adjusting the diff from a lower setting and raise the % on the next lap and when it starts getting high you will feel the trigger respond differently with a harsher rumble. Hope this helps it sure did for me.
Thanks everyone for your insight!
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Did you notice any difference in lap times? I think the rumble would mean you are losing grip through wheelspin, even if unnoticeable to the eye, you may be getting enough slip where its slowing you down.