[Magic inside!] Need Help With Differentials

[Gix916]

the only car that i've felt the need to tune so far has been the Renault Clio, on the tuning setup for that you can turn all the diffs on at the same time or all of them off. I wasn't sure if that was meant to happen or not.

so if a geared diff is driven by gears, a clutch diff uses plates and a viscous diff uses plates in fluid, a spool is a complete locked up diff, and ratcheting is diff fully on or off, how can a car have all of them? shouldn't this default to what type of diff the car actually uses?

[sp3ctor]

I wonder if it makes a difference that I race in game pad as to why lowering preload helped me gain stability out of the car.

I agree with this. The first thing I would do in PC1 when a car felt skatey was to lower the preload and viscous and, in most cases, turn them off, and the car would feel less unstable. Trying to figure out what to do now because I'm assuming that isn't optimal... however, I have noticed when I turn preload all the way down it has the same effect on feel in PC2 but I'm not sure it helps times.

[Jussi Karjalainen]

Hey, you do what works for you. =)

[Aldo Zampatti]

I wanted to take the opportunity to publicly thanks Jussi for spending so much time here since he (as every other Dev) are probably stuff up with work!.

I enjoy reading your technical post since 2011, so I hope everyone else does as I do.

[DeathMetalRacer]

Any chance someone could take the time to explain how to use Jussi's diff calculator? I downloaded the spreadsheet from the link but having never used a google doc spreadsheet before I'm not exactly sure how to use and read it correctly. Thanks!

[Aldo Zampatti]

Any chance someone could take the time to explain how to use Jussi's diff calculator? I downloaded the spreadsheet from the link but having never used a google doc spreadsheet before I'm not exactly sure how to use and read it correctly. Thanks!

Sorry buddy, Einstein died long time ago, and he was my only hope to understand that.... 2nd option is a PhD in standford but I can't afford it :P

/jk

[DECATUR PLAYA]

I wanted to take the opportunity to publicly thanks Jussi for spending so much time here since he (as every other Dev) are probably stuff up with work!.

I enjoy reading your technical post since 2011, so I hope everyone else does as I do.

^I 2nd this. Have always enjoyed Jussi's work. Was the perfect person to promote.

Jussi I have a couple questions. I'm good with the rest of the setup but right now I'm absolutely scared of the Differential and Dampers.

1) Does power ramp = limited slip acel
Does coast ramp = limited slip decel

2) Can bumps and rebounds be explained by feel. What should I feel by making the adjustment up or down. Most of my tuning is by feel.

[Jussi Karjalainen]

Any chance someone could take the time to explain how to use Jussi's diff calculator? I downloaded the spreadsheet from the link but having never used a google doc spreadsheet before I'm not exactly sure how to use and read it correctly. Thanks!

It's fairly simple, at it's heart it's just a converter from clutch numbers and ramp angles to the old style locking effect percentages familiar from pCARS 1.

You just fill in the numbers from the game into the green fields and read the resulting locking torque percentage from the yellow fields. A and B are just for comparing two diffs, for example the change of adding more clutches. Then you can fiddle around with the numbers to find what you need.

^I 2nd this. Have always enjoyed Jussi's work. Was the perfect person to promote.

Jussi I have a couple questions. I'm good with the rest of the setup but right now I'm absolutely scared of the Differential and Dampers.

1) Does power ramp = limited slip acel
Does coast ramp = limited slip decel

2) Can bumps and rebounds be explained by feel. What should I feel by making the adjustment up or down. Most of my tuning is by feel.

1. Yes, power ramp controls the limited slip acceleration locking, and coast ramp controls deceleration locking. However the numbers there aren't the same as the old percentages. Use the calculator to get exact numbers or adjust by feel, higher number = less locking, lower number = more locking.

2. To some extent. If the car seems to wobble or sway around a lot, your damping is probably on the low side. If the car feels kind of floaty (not boaty, that's different), like it's sort of skimming over the surface of the track, your bump damping might be too hard. Another common sign of having a bit too stiff is if it has very sudden reactions. Turn the steering wheel a bit too quickly and suddenly you lose front grip and start pushing. When the tail comes out it does so in a very sudden and violent way (can be a tyre issue as well). A good setup usually has the bump damping stiff enough that the car feels steady and not too soft, while still being soft enough that you get progressive responses from the tyres. Rebounds in racing situations are usually set quite hard and it's often not that big of a deal if they're a bit too hard even. Too soft though and again you have trouble controlling the body of the car.

Of course exceptions abound, and some modern cars go with super stiff bump damping and very soft rebound damping (so total damping is about the same, just the setup is reversed) to work the tyres hard, and some really high aero cars mostly just care about making absolutely sure the aero platform is stable, and essentially lock up the suspension with very stiff damping. There are many way to do things in the suspension world...

The problem though is that both too stiff and too soft damping can cause the same kind of instability issues on the car, though through different mechanics.

I'll be releasing a damper and spring calculator later this week (might be on the weekend) and in the future will also release some new videos on how to work with it.

Until then you can sort of get a feel for what's coming by looking at some of my old videos (from before I started working at SMS) as well:






Note that these videos are old, and the new calculator will have a different look to it due to the various added features in pCARS 2. And even if you're not interested in using the calculator I do talk about some general level damper tuning stuff in them.

[hagar147]

Because of the lack of a 'garage/setups' section in this forum, I am posting my question here.

In the car setup menu in Project CARS 1, there was a deceleration/acceleration diff lock setting that I can't seem to find in Project CARS 2.
Could someone tell me which value(s) I need to adjust in PC2?
e.g. If I liked a high deceleration diff setting in PC1, what would I need now?

Kind regards,
hagar147

[Bealdor]

Threads merged.
Pleae check out Jussi's posts here in this thread.