Physic discussion thread

Can I hire you for some corporate management gigs? You pitch it at just the right level... my managers could learn a great deal

 

Agreed.

Final extended version of the graph that also illustrates what happens at 80 sensitivity.

 

That can be overcome with an inverse tachyon pulse, and some positive toe in at the front wheels.

 

Don't forget the effect of the 'jiggle pin'
+
Car of the week

Spoiler: pin

ABCs of Thermostats – Replacement Auto Thermostat at Thermostats.com

 

Impressive drive.

 

@Dean Ogurek .yes impressive or a better word
Nemisis 69

There are aliens and Then aliens

 

I like the physics anyway, but the car slides way too easily even with a little throttle. It feels so unnatural. The same problem was with PC2. I hope they will fix that in some day.

 

Welcome to physical tyre models.

 

Try trottle sensivity to 10

 

37 is the new 50

 

I don't believe a lot of them do though...In fact the torque curves and lack of bogging down was something else I've mentioned before, and may in part be related to this through the drive train coding obviously being tied with throttle application etc.

Example: BT44 on my gear (Logitech) as per a couple game versions back.
* Set off spinning the wheels.
* Ease off/feather the throttle, and try to feel/regain grip.
If you know what you're feeling for, you'll notice that as you ease off throttle, rather than the tyres gripping up (Or least slipping less) AND importantly the car realigning/straightening up...
The rear actually reacts in the opposite way much of the time. It kicks out, as you're easing off.

Honestly, give it a try.
You may have to try this several times before 'feeling' it and being able to see it visually.

It felt massively obvious to me with the BT44, the most obvious car I've felt this in actually (Which prompted me mentioning mapping again) but I do feel this in a lot of the cars. No car I've ever driven, whether track or road has ever reacted like that. Even varying turbo'd cars where you can have delay/lag/anti-lag/lazy throttle response.

It's as though the rear wheels weigh ten TON and keep momentum going (Or even accelerating) after you've let off throttle. In real life, you can expect a minimal to zero delay as traction comes back, but not the opposite like this.

And I think it's at least partly down to the mapping. Easing off to part (Even very little) throttle should do 'x', but as we have seen, part throttle can be 4K RPM or nothing. The BT44 really, really showed this issue for me a couple of versions back.

By the way: (Sorry Bruno )
For anybody suggesting people should follow this stuff up (Which is good), I apologise for my lack of that, but I'm actually very unwell and can very rarely do any gaming at all. All I can do is go off what I feel and see where possible, and compare it with my real life experience.

 

what happend to 18?

 

I suspect this has mainly to do with the FFB configuration rather than the physics. For me, the default FFB is also like this in the BT44, just way overactive in terms of rear slip and wants to kick out constantly. I can't really drive the car with the default FFB. A well-tuned custom FFB (rFuktor 4.6 with some tweaks for my wheelbase) however has no such issues, and the car is still tricky but much much better to drive.

 

Overall I love this game and it feels great however there is one thing that I can't wrap my head around.

When you're in lowspeed corners and you have understeer you can often combat it by applying throttle and the car all the sudden turns more. I'm not talking about enough throttle to make the car spin but just enough so it turns around on itself.

Shouldn't more throttle make the care understeer even more and not the other way around?

Is it the tyre start stars flexing and rolls on itself that creates it?

I have no idea about these things obviously, would just want to get some input on this behaviour.

 

My understanding is that in slow speed corners without throttle the differential is in coast. If the diff setting has a low coast ramp angle (high locking force) or too many clutch packs the rear wheels are going too slow for one to skid or slip and the car won't rotate easily whatever the front wheels do.

Once you apply throttle the power ramp angle determines the differential locking and with a high ramp angle (low locking force) and enough power to open the clutches the rears will spin independently more easily enabling car rotation.

 

Not to disagree with you, but I will point out this is the exact opposite of what a limited-slip differential is meant to do in real-life.

 

Agreed. This combined with power oversteer creates that contrast where it doesn't like to rotate off power, but does rotate on power.

This is one explanation, but doesn't explain why the Super V8 with its spool, or just basically every car in AMS2 near v1.0, acted like this. Rear tires sure turn at the same rate with a locked diff.

But I don't have a physics explanation for why this is. We do know that a locked differential is detrimental to rotation off power which is why differentials are used to begin with. My only guess is that by introducing more slip to rear tires it loosens up and this negative effect decreases. You also get typical power oversteer much easier which is all the rotation you could want plus more. Pls help @Ettore

 

For an average differential in a road car, this is usually the case. Most are simple just applying a static amount of friction to lock each axle together. However clutch-type limited slip differentials that use clutch plates and ramps are specifically designed to be tuneable in coast or power. These are highly tune-able, racing differentials, and are intended to be able to be adjusted to be as loose or as tight as you want them regardless of whether that is on power or coast. Depending on the car setup, it may just be how its adjusted.

Given the issues Reiza seems to have had figuring out the differential modelling, and the default setups moving around, who knows how it's actually behaving. I will say Im not convinced the game models this well at all. I've seen telemetry showing it working "fine", but it doesnt feel right to me.

It could be that the car he's driving is prone to unloading the inside rear tire in a corner, so applying throttle causes slight over steer that helps through the turn, but I've given up on the diffs and traction under power in AMS2 ever feeling "right". There are some cars that feel wonderful but many need a little work.