Bump/Travel/Height

Continuation of my exploration of how the game engine works, what is affecting the Bump, Travel and Height displayed in the telemetry ?



How do they correlate to the car setup screen ? More specifically, the Travel, I can't figure out what is determining its value.

 

Static ride height (from setup screen) = Bump + Travel

The height value from the telemetry HUD doesn't necessarily represent that value because it's not measured at the wheel/suspension but at specific (undisclosed) points on the chassis.

At least that's how it worked in PCARS 2.

 

mmm is AMS2 working differently ? See below I posted 2 setups where I only change the Bump Stop value but the sum of Bump + Travel at standstill in the pit does not seem to correspond to the ride height and even differs between each setups, am I missing something ?





Edit changing the spring rate does not alter any of those values.

 

Travel is how much the spring needs to compress to hit the bump stop.

 

So in the case above, by increasing the bump stop by 2 cm, we reduced the suspension travel by 1 cm correct ? Is it a factor of 2:1 ?

I struggle so much, here is another example with bump stop set at 0, 25, 50 and 100 (nothing else changed) :


Send help please ?

 

Well it probably has to do with the motion ratio

 

Nobody noticed the last example? How did the travel increase? He went from 5 to 10 on the bump stop and the travel increased instead of decreasing.

 

I don’t know how to explain it except saying maybe Reiza should limit the bump stop height to something related to the set ride height

 

That looks to me like either that car or the way its calculating in general is wrong. Something is definitely not right there. Everything made sense until he went past 5.

 

Yea this might be a bug where the numbers go out of whack if the bumpstop value go higher than the available travel. I agree, sounds like Reiza should just limit the max value of the bumpstops.

 

I have never understood the bump stops in AMS2, whether set to max or min, suspension soft or hard, any combination, I have never seen them engaged in telemetry or felt them in ffb. It's pretty obvious in the telemetry in ACC when they engage, suspension travel flat lines, and it can be clearly felt in the ffb. I have never seen/felt this in AMS2 regardless of car/setup/track. I have not however driven every combo available, but have explored the extemes in setup of every car I have driven.

 

Bumpstops in AMS2 aren’t really Bumpstops, they’re packers which just set a minimum ride height

 

Either way, or whatever they represent, you can't set them so the car doesn't bottom out, even on the bumpiest tracks. Currently driving the P2 Rocco, been to Bathurst, Adelaide, Kansai, Interlagos, Long Beach and Road America. The car will bottom out with max bump stops, softest suspension, and lowest ride. They simply don't seem to engage or make any difference. Is it perhaps that I am dumb and 0 ride height in the telemetry is always represented by the bump stop setting rather than the actual ride height between chassis and ground?

 

Just a note that it's the first thing I changed, to ensure the ride height is at minimum the same as the maximum bump stop, I was using the Huracan ST and the above screens were taken from the rear with a ride set to 100 as well. I am trying to stabilize that car, because it has way too much movement, having seen a couple in real life they just don't jump as much, it almost feels as an american low rider on hydraulics right now That's when I came accross those weird numbers that I am trying to make sense of.

This game desperatly need a fully documented setup guide, written by the devs themselves explaining how things work in the game engine, the community can only go that far figuring stuff out.

 

I know I am no dev, but I have a setup guide on the wiki which I can adjust to add these things

 

I can feel the difference in ffb of changes to bump stops , it reduces compression in big dips

 

Seems we can't have discussion pointing out issues without being censored, sad... Did some testing using Motec and it definitely shows that once you make the travel reach 0 you ride the bumpstops and anything above (55-ish mark on that car) is just 0 travel whatever the game shows you even if after that breakpoints it goes into positive value again. Even if tests within Motec in regards to suspension need to be taken with a huge grain of salt (unless someone points me to a way to sample the telemetry with a frequency higher than 60hz). So my guess is that the engine end up calculating negative values and just display the absolute value in the in-game telemetry, but does not apply it in its physic calculation.

 

What did you say which got censored?

 

AFAIK AMS2 telemetry channel Susp Pos data is defined as the gap from actual suspension position to the bumpstop (as a packer) so the resulting (available) travel will decrease as a result of a higher bumpstop.

The same rule applies to Ride Height channel: Actual position means the gap from the reference point (corner undertray?) to track surface (probably but not shure).

In both cases, travel will result from the difference of the actual reading to the stationary reference value by telemetry.

We users don't have any official information at this regard.

Your data show confident values when rising bumpstop from 0.0 to 2.5 to 5.0cm (wich is a LOT). Resulting travel must be seen as "available travel" and that makes fully sense to me as 1.4cm is very close to the estimated 1.5cm as half way of 3.8 to 0.8cm.

More than that, bumpstop at 10.0 can be more than the suspension available travel, don't know in this specific case. All I can say or suppose is "it is so high that can be a possible exploit". Even 5.0cm is too high.

Sorry for any possible mislead as I don't have but the very basic English skill.

 

I suppose you are using a plugin to read telemetry on MoTec right? I use this one

Release v1.8.6 · GeekyDeaks/sim-to-motec

and you can actually choose the sampling frequency.