Quote from kaynd :

...by keeping realistic settings, like normal tire pressures (170-200kPA), low camber (1.5~1.6), low-mid diff locking (25~50) and with enough ride height so it is not that easy for the dampers to reach the bump stops.

As for your sets axus, I like some of them but in general I think that it is not always well balanced to keep the absolute minimum coast locking… especially when you are using very high power locking.
Because I am still away from my wheel I can’t give specific feedback but the turn in overseer is a bit excessive in some of your sets like the FZR’s
Also try to watch out the spring length you use cause the LX4’s set is bottoming out way to easy.

Don't worry so much about keeping the negative camber that low. It is very common for a production based race car to use -3.0° camber on the front tires.

I find that with reasonable power locking and very low coast locking and no preload, there is too much difference in reaction to throttle between the two states. In other words, I coast into a corner and the car tucks. You have to be ready with throttle to counteract the oversteer. But, when you get on the power, the higher power locking causes understeer... which is what you want to a degree. But it just doesn't feel balanced. There is too much difference between coast and power locking making the car twitchy. A steady state of turn in or track out is never achieved. It is easily fixed by bumping up the coast lock a bit and adding a touch of preload.

This probably has more to do with my driving style than a deficiency in the setups though. The nice thing about those sets is that you can really feel the difference in the differential settings, even when you are only making small changes. I was able to get the LX6 set to balance nicely for my driving style with just a couple of minor changes to the diff settings. This is one of those things that really highlights just how good LFS physics and car models are.

Where are all the good XRR setups?
Whenever I try to do a setup it ends up being too twitchy and the car still understeers too much for my liking.

Quote from geeman1 :

Where are all the good XRR setups?
Whenever I try to do a setup it ends up being too twitchy and the car still understeers too much for my liking.

That's the next car on my list.

Yay!

Quote from Hallen :

Don't worry so much about keeping the negative camber that low. It is very common for a production based race car to use -3.0° camber on the front tires.

That’s why I said it is a “sporty” set meaning that it is more like a road going set.
Anyway because it has no rear anti roll bar and the front roll resistance is more than 2x grater comparing to the rear, the rear inside tire stays loaded while turning, so low negative camber value helps the inside tire have a decent contact patch with the road. Also the high tire pressure minimizes tire deflection, so that -1.6 deg is ok and helps the tire heatup evenly.
As for the front tires… well only 40% of the cars weight is at the front and tires seem to be even front and rear… Rear weighted cars have wider tires at the back (eg FZ50)
So I did keep also the front camber low (~1.5) despite the huge weight transfer to the outside tire cause of the (a lot) harder front suspension.

In my opinion, generally low (till a limit) negative camber values help the car be a bit more predictable and loose traction more progressively. That’s what I wanted to achieve with that RAC set.

Quote from Hallen :

I find that with reasonable power locking and very low coast locking and no preload, there is too much difference in reaction to throttle between the two states. In other words, I coast into a corner and the car tucks. You have to be ready with throttle to counteract the oversteer. But, when you get on the power, the higher power locking causes understeer... which is what you want to a degree. But it just doesn't feel balanced. There is too much difference between coast and power locking making the car twitchy. A steady state of turn in or track out is never achieved. It is easily fixed by bumping up the coast lock a bit and adding a touch of preload.

That’s exactly what I had in mind, when I wrote the comment “it is not always well balanced to keep the absolute minimum coast locking… especially when you are using very high power locking.”

I really find it quite managable. Though that's quite driving style specific so people might want to understand the principles behind diff tuning so that they can tweak them so that they are just right. Todd specifically told me to use as little preload and coast locking as possible though. And for me, it works.

Old 60s F1 cars used cam and paw diffs wich means 100% locking on power, 0% on coast and no pre-load. Many teams took a while to switch round to clutch pack diffs. If they could drive the cars like that, then we can sure as hell get cars to work with more manageable settings.

My car has a cam and pawl diff. But for all I know it could be totally worn out

Quote from Bob Smith :

Old 60s F1 cars used cam and paw diffs wich means 100% locking on power, 0% on coast and no pre-load. Many teams took a while to switch round to clutch pack diffs. If they could drive the cars like that, then we can sure as hell get cars to work with more manageable settings.

Reminds me of pre-patch W days. But i can't remember much before 'cause i had recently started playing back then.

Quote from PwrSlave :

Now correct me if im wrong, but imo devs have made this patch for sprint racing, as all of given tires atm cant preform as they did before.

So you are saying that you prefer patch X where one would pick the softest tyres no matter how long the race was or what car were you driving? If your R2s are getting roasted - pick a harder compound.

I think it's much better now that there are substantial differences between the compounds. Granted, the whole grid usually will use the same compound for the race but then again usually one of the R1-4 is the most optimal for the conditions and it would be silly to choose otherwise.

Fast and easy to drive setups Axus. Keep em coming!

This will do 1:07.xx and it's much more stable I think. I've already got an early version of the XRR setup but it still needs work before I'm happy with it.

EDIT: Tried it on some other tracks too. It's just the kerbs that upset it really. I'm working on rectifying that and I'll post an updated one later.

EDIT2: Here is the updated setup. It's now called "RealRace" because it works well pretty much on every track, except South City where it would need a few camber tweaks at least, and more downforce.

Quote from Tunari :

Fast and easy to drive setups Axus. Keep em coming!

+1. Loving this thread.
Is the FZ5 on the 'to do' list per chance?

All the RWD cars are on the to-do list (and probably the 4WD ones). I'll be revising every setup I posted so far apart from the FZR one which I'm happy with. Having seen that it's possible even for the FZR, I'm sure I can get some balanced all-rounder sets for the rest. Progress will be slower now though - I've been lazy for long enough, gotta get some real work done.

Quote from kaynd :

I made recently a general “sporty” setup for the RAC trying mainly to make it more (?) netural… a bit les mid corner understeer but also less unstable while changing direction, maybe a bit less understeery on the corner exit while keeping it kind of predictable while loosing rear traction because of excessive wheel spin.

Brilliant setup, I love it. I am an absolutely lousy driver and now I can finally learn how to drive the RAC, since it isn't so terribly frustrating anymore! Very chuckable and always controllable, I didn't think this was possible for the RAC.

Thanks

I am glad that it helped someone.

Since I am with my wheel again, I spent some time trying to make that set less understeery while keeping good balance.
Unfortunately the luck of rear antiroll bar ruins the balance. (in that case, while turning, a stiff front antiroll bar lowers the front of the car way more than the back… That causes first turn in oversteer, then mid corner understeer and at the corner exit while you decrease the steering angle, redusing the antiroll bar’s effect, the front suspention decompresses sending weight to the back creating some more corner exit oversteer.)
So I got rid of it... Hardened up the springs to get the same total roll stiffness as in my previous set and tested various settings in that way.
The front antiroll bar is set to 0 and you can use it for fine tuning, adjusting it by 1 or 2N/mm to kill any unnecessary oversteer... till a limit... it's not super glue or something
I am happy with the result. For me that’s better balanced (maybe not easier though) than my previous set and it still has high tire pressures and reasonable mid low negative camber values.

[edit] with the front ARB set to 2N/mm it handles like a dream for my driving style at blackwood.
But anyway this is a general base set so I leave it to 0 [/edit]

Quote from kaynd :

I am glad that it helped someone.

Since I am with my wheel again, I spent some time trying to make that set less understeery while keeping good balance.
Unfortunately the luck of rear antiroll bar ruins the balance. (in that case, while turning, a stiff front antiroll bar lowers the front of the car way more than the back… That causes first turn in oversteer, then mid corner understeer and at the corner exit while you decrease the steering angle, redusing the antiroll bar’s effect, the front suspention decompresses sending weight to the back creating some more corner exit oversteer.)
So I got rid of it... Hardened up the springs to get the same total roll stiffness as in my previous set and tested various settings in that way.
The front antiroll bar is set to 0 and you can use it for fine tuning, adjusting it by 1 or 2N/mm to kill any unnecessary oversteer... till a limit... it's not super glue or something
I am happy with the result. For me that’s better balanced (maybe not easier though) than my previous set and it still has high tire pressures and reasonable mid low negative camber values.

[edit] with the front ARB set to 2N/mm it handles like a dream for my driving style at blackwood.
But anyway this is a general base set so I leave it to 0 [/edit]

I like it! It feels more controllable and responsive under partial throttle now. With 0N/mm ARB the oversteer is less snappy but occurs a tad early in highspeed corners. With 2N/mm the snap oversteer is back but even for me it's still possible to keep it close to the edge. While your first setup was clearly safer, the car is now more fun to drive, so I'll stick with the new one for a bit.

Already had some fun online with the old set yesterday, Redline seems to be running LRFs now, woot.

Thanks for the setup, greatly appreciated!

Racecar Engineering had an article some time back that discussed differentials and their effects on a car's behavior. Their example car was some race prepped Porsche, modeled up in some software (not sure what specifically) and was presented some basic inputs like steer angle, torque load, speed, etc. to provide some mid corner state. From there, they discussed various effects different preloads and locking behaviors would have on the car's balance (understeer/oversteer) and maybe some side-effects. The article was a bit complex in explanation. However, the gist of it was diffs are complex, not in their behavior but rather in their effect on the car. Essentially, the proper diff setup was very dependent on what was going on at a particular time. If you changed throttle level, accel/brake, changed steering angle (changing tire loading), you get very different results and different differential needs to maintain a neutral balance. In the end, you sort of make a best fit setup that was tailored to track and driving style as best you could and leave it at that. There are some basic behaviors you can control through adjustment, but most everything is a trade-off of one thing for another.

You guys argue about locked diffs and high locking and preload, but in reality, it's perfectly fine as long as it creates the desired resuilts. I'm glad some folks love it. I hate it, lol. I tend to tune my setups through spring/dampening/brake bias rather than trying to fix an imbalance through the diffs. Then again, it's all driving style and certain diff setups and certain suspension configurations will suit certain people better. It's just another tuning option.

Hello.

I've been toying around with setups lately because I also dislike the behaviour of high-locking diffs. However, I ran into a problem.
The symptom is that the inside rear tyre keeps heating up immensily while accelerating out of corners.
To see wether it was my mistake or a methodical problem I compared my sets to yours. I'm attaching a screenshot of the forceview of your latest XRT setup on Westhill Rev. Notice that the longitudinal force is about zero and that the loaded outside rear wheel has large amounts of traction left, but the inside wheel is easily overwhelmed by even very few lateral force. That means, even at 0% throttle the inside wheel limits traction.
Any attempt to accelerate out of the corner would cause the inside wheel to spin up because even now it's beyond it's traction elipse. The point now is that the lower the locking factor the higher the torque on the inside wheel will be and thus the more power will be squandered as tyre-heat.
Under these circumstances the ideal solution would be a locked diff, as it'd keep the torque at the unloaded wheel as small as possible which means that the most possible amount of power will be used to accelerate the vehicle.

You can experience that yourself by using a variety of sets on a track. Start with a low locking set and notice that the inside wheel is always hotter than the outside wheel (e.g. with your 42% locking diff on the XRT), add more locking and notice that by the time you reach the locked diff the outside wheel is always hotter than the inside wheel. What happened is that as you increased power locking you used less engine power to heat the spinning inside wheel and turned it into actual acceleration instead.

I'm wondering wether this is a real life problem or are the LFS-friction coefficients simply wrong for very low tyre loads?

Vain

Quote from Vain :

I'm wondering wether this is a real life problem or are the LFS-friction coefficients simply wrong for very low tyre loads?

I get a invalid link error when I click on your attatchment

I think this is a situation in LFS that is amplified much greater than in RL at the moment. I'm sure it will improve in the future

Quote from Vain :

I'm wondering wether this is a real life problem or are the LFS-friction coefficients simply wrong for very low tyre loads?

Vain

As far as I understand that exactly the problem with low lock diffs and open diffs. Because the weight lays on the outside tire its easier for the inner tire the spin, therefor it gets more torque through the diff and slips, causing it to heat up more.

I don't know at which locking this would still happen in RL, because the LFS grip physics are somehow not quite correct (why is spinning your wheels at start still faster), but it would.

See here how a open diff can not handle too much power (in Stigs lap)

I've not noticed the inside heating problem with power locking over 30% (on road cars anyway), this always seems enough for me. Perhaps you're applying throttle too soon after the apex of the corner? Or your set is quite high, thus increasing weight transfer.

The inside wheel loses traction under *no* power. That means *any* amount of power automatically causes excessive tyre scrub. That is not at all 500 hp. Very far from it.
And regarding Bob's reply: That's axus' set. It's just as stiff/low as any other set. Actually, the problem that the inside wheel loses traction regardless of lateral force arises with every set. On Westhill this translates into heat though because there are many long corners that are driven under throttle.
Of course I could always apply fewer throttle, but this isn't about sunday driving. Fact is, I have traction left on the outside wheel but the inside wheel is already well beyond it's capabilities even before I apply throttle at all. That immediately leads to the fact that a high locking factor is the way to go.

Quote from Vain :

That immediately leads to the fact that a high locking factor is the way to go.

It’s not about high or low. It’s about having just enough locking.
That’s why it is part of the setup… usually on a track with low speed corners (close to 90deg) you need a less locked diff to put the power down than what you need while exiting from a fast bend.
Axus set may work fine on Blackwood but not on Westhill

Also the proper diff’s locking factor is hugely affected by the roll stiffness relation of front and real suspension. With a softer rear end you could give a bit more traction to the rear inside wheel and that affects the needed locking factor.

try all of the following (1 or 2 clicks only)
Stiffer rear ARB
stiffer rear bump damping
softer rear springs
less camber on inside rear wheel

all trying to give the inside rear a tad more weight. methinks that is caused by the rear inside lifting off the ground.