Some questions about differential settings

Chris · Dec 20, 2016

Posted this on the AMS forums last week, but got no replies from anyone so I thought I'd post it here where it's a little more active

I've been searching the web for a definitive answer on this but it seems as if some sims handle differential settings differently. So, I have a few questions as to how AMS handles the three diff settings...

Diff Power:
In short, the literature says that a higher percentage of diff power will lead to more on-throttle oversteer as the differential is locked more quickly during throttle application, however, I've often felt that in AMS, the higher you set the power percentage, the more diff slip there is, purely from the feedback that the car gives me.

Does AMS actually simulate it this way? Or is this just all in my head, and it's actually the case that lower you set the Diff power percentage, the car will exhibit more on-throttle understeer?

Diff Preload
I'm still not entirely sure what this setting does? I've read up on it but I'm a total noob with technical things like this. Something to do with the smoothness of the transition between off-throttle and on-throttle car behaviour?

As for diff coast, well I already know that one pretty easily so no issues there.

If anyone with more technical knowledge than myself could please explain how AMS handles these settings it would be massively appreciated.

*cough* Niels *cough*

Cheers!

Shaun.A · Dec 20, 2016

I thought I would post here what I believe the settings to be.

In terms of diff power, the lower the number the more that the inside tire is disconnected from the outside causing it to spin on its own in certain corners. This does help with power oversteer. As I understand it, AMS does it in this way and there is a video posted by Niels where he is testing the diff settings on an F1 car. In this video he showed that it indeed does work in this way, so it might be in your head. You also have to take into account the balance of the car as that can also affect the power oversteer of a car.

The diff preload acts pretty well like you think. The lower the number the quicker the diff will transition between coast and power. Having the preload on 1 is typical for most people, especially the faster guys as this allows them to get on the power quicker through the corner and help rotate from the apex. If you have issues with snap oversteer or understeer you can try increasing this number to see its effect. At best I believe any changes to this setting is minimal, but try and keep it as low as possible.

This may not be the most technical explanation, but I hope it has helped.

Thanks,
Shaun

Chris · Dec 20, 2016

Cheers Shaun! I'll have a fiddle around and see what's what.

It's really odd, it felt for a long time in the V8 Stockcar that a higher diff power setting would give more on-throttle understeer. But then I experimented at Bathurst in the practice session and found that a lower number felt slightly nicer.

I feel like the preload plays a massive role in all of this haha.

Shaun.A · Dec 20, 2016

Chris Stacey said:
Cheers Shaun! I'll have a fiddle around and see what's what.

It's really odd, it felt for a long time in the V8 Stockcar that a higher diff power setting would give more on-throttle understeer. But then I experimented at Bathurst in the practice session and found that a lower number felt slightly nicer.

I feel like the preload plays a massive role in all of this haha.

It is possible that you could get more on throttle understeer, especially if the rest of the set-up is going towards understeer. As both tires are beginning to spin at the same rate, if the rear has plenty of grip it will understeer. In the Stock V8 having a high front ARB will almost always result in understeer and appears to be more noticeable on throttle out of a corner. So in your testing have a look at either adding a click of rear ARB for rotation, or reducing the front a little, but not too much.