[MVRC] Mantium Virtual Racecar Challenge 2025 (Grand Prix Cars)

[LVDH]

So, to fix this potential suspension issue, please make sure that all suspension parts are in the correct folders. If you are sure they are, please send a screenshot or two, or provide me with the case.

...
We completed the CAD design and are trying to run the first case with MantiumFlow. I've got the following errors during the STL import:

Warning: Something went wrong with the CoR calculation, CoR set to 0,0,0
Warning: Front wheels seem to be positioned incorrectly. In MVRC they should be in global (0,0,0.3).
Warning: Rear wheels seem to be positioned incorrectly. In MVRC they should be in global (3.4,0,0.3).
Warning: Car seems to extend maximum allowed dimensions.
Calculated ride height at: 0.04000

I also tried to use the V6 rule geometry for front and rear suspension/wheel/etc., but still the same warnings.

Moreover, I had terminated runs during the tutorial of the shark and car_coarse cases:

ERROR: Failed to post close command error 1726
ERROR: unable to tear down the job tree. exiting...

I'm hoping you can answer these questions. We are stuck with them currently, and our excitement grows getting closer to the submission deadline.
...

Please check this out:
https://mantiumflow.com/question/error- ... rror-1726/
As time is running out, you should send me your case, so I can have look at it myself.

[yinlad]

Hi everyone!

Very interesting results from the first race, and congratulations to JJR!

I have run my first CFD simulation today, and as I have a disappointingly long list of issues to fix, I would like to request the 2 days extension for the first time, please.

I think there is a problem with the Mandatory Suspension parts movements in MFlow. My suspensions sit in the right place when I import them in MFlow (so nothing to do with Matteo's issue), but as soon as Rake and/or RH adjustement is applied, the Mandatory suspension rods move weirdly and quite differently to the parts that I have designed (which appear to move sensibly). Can you please double-check that, and ideally remove these parts for the official simulations?
I wonder if this issue gave unexpected results to multiple competitors in the first race. Thank you in advance.

I agree with removing the template representing the structural core of the suspension arms for the Monaco Race (Race 2), since it's causing issues. While we're at it, can we also remove it from the geometry used for the Race 01 calculations?

By the way, i think I have the same issue:

https://www.caedevice.net/SERVER/MVRC/2 ... w_only.jpg

Welcome back, G-Raph! For a few days I thought I might make it to the podium, but I think I’ll be stuck in 4th place.

Pro tip on the suspension front is to merge the mandatory part with your fairings. I’ve found that helps everything transform correctly when adjusting ride height.

G-raph returning is a cat among the pigeons. I’m happy with the progress I’ve made for this race but I’m not sure it will be enough to cover off any progress JJR makes. Not to mention the ever present threat of Variante. I’ll try to get some renders up this weekend but honestly there’s not that much difference visually between R01 and R02 for me

[CAEdevice]

Pro tip on the suspension front is to merge the mandatory part with your fairings. I’ve found that helps everything transform correctly when adjusting ride height.

yes, that is what I do in my local simulations, but in official ones the inner arms are separate components

[LVDH]

Ok, so I have looked into a problematic case.
These are my findings:

• The issue, is not, as suggested by GRaph, what we saw in the first race. In the first race, we had three teams that had suspension parts that were not positioned correctly. (This does not mean that we did not also have this new issue already in race 01)

• As yinlad suggested, it sounds like MFlow only picks up one part and then morphs it. Would have been nice, as it would be a bug from my side that I can easily fix. Sadly, MFlow picks everything up in the folder and morphs it, just as it should be.

• It seems like the morphing process is not clean enough. This mostly affects teams that have super tight suspension covers.

Now what do we do for race 02, this weekend?
Here are my two suggestions:

• We just remove the mandatory suspension core parts from the simulation (not from scrutineering)

• The teams design covers that works with their car setup.

Please, also make sure that you have a valid link to submit your car this weekend. The newest email went out yesterday.

[yinlad]

• We just remove the mandatory suspension core parts from the simulation (not from scrutineering)

I'm happy with this but people will need to make sure they have covers for all arms. In R01 for example (and currently for R02) I don't have a cover on the front pull rod, so if we removed the mandatory part I'd have an unfair advantage because there would be nothing where the pullrod should be.

If you make the call to run without the mandatory parts, I will add a pull rod in (or submit the mandatory parts as a merged part with my fairings)

[LVDH]

Not sure, if this equates an unfair advantage.
But anyway, I actually favor that the covers should do their job. Even if the inner core / rod parts interfere because of imprecise morphing. In real life you will have these issues for one reason or the other.
Here, we can see that some teams have noticed that there is an issue. Some now voice questions about it, but I am sure others just stayed quiet and tried to build covers that do not have issues.

But, for those that do not agree: Maybe we can keep only the front pull-rod for this race? Somehow many teams do not cover it.

[CAEdevice]

I vote for option n°1

"We just remove the mandatory suspension core parts from the simulation (not from scrutineering)"

Possibily also from the simulations of the previous race.

[The Rusted One]

I vote to remove the mandatory suspension parts except for the pullrod cause I have a cover for that and would be at a disadvantage... or I can just remove the pullrod from my submission but ill need to know soon.

[yinlad]

Somehow many teams do not cover it.

The regulation volume is too narrow to create anything of consequence so I chose to invest the time elsewhere instead of working on a pull rod cover and how much it might need to twist given the flows it crosses over. It felt like it would be easier to make things worse than to keep the default part.


I’ll submit my suspension as normal but with a pull rod in place such that whatever we choose to do I’ll be safe. I’ve just had my final correlation run finish, I should be submitting my V1 entry this evening.

[LVDH]

Maybe, these are the two options for us to chose from:

• We remove all internal parts, where we have a cover.

• The internal parts stay as they are and the teams have to design covers that also work with the current morphing capabilities that we have.

Right now, we only have few teams chiming in. I know, close to a race everyone is very quiet and busy, but this might be a time to speak up.

[Ft5fTL]

My vote would be removing the mandatory suspension core parts from the simulation (not from scrutineering). I believe it is the easiest and the most effective solution for the problem.

[KaraszG]

So, to fix this potential suspension issue, please make sure that all suspension parts are in the correct folders. If you are sure they are, please send a screenshot or two, or provide me with the case.

I have submitted our application (SwiftRacing_02_01). I hope I provided all the essential parts. Reading the previous discussion, I hope we have the same wheel placement issue as others, and it won't be a problem.

FYI: Also, I am Gergo asking about the

error-failed-to-post-close-command-error-1726

Other question. If I am correct, I must submit the brake duct/wheel hub with the rods, but not the wheel itself, in the frt and rr suspension. In the high-res folder, I have to submit the mandatory halo and mirror elements too?

Thank you in advance!

Gergo
from SwiftRacing

[G-raph]

Maybe, these are the two options for us to chose from:

• We remove all internal parts, where we have a cover.

• The internal parts stay as they are and the teams have to design covers that also work with the current morphing capabilities that we have.

Right now, we only have few teams chiming in. I know, close to a race everyone is very quiet and busy, but this might be a time to speak up.

As mentioned before, I would be in favour of removing the internals parts for that race when covers have been submitted. In case not all suspension members have a cover, Yinlad's solution should be recommended.


I don't think the problem has anything to do with the number of parts in the suspension folder. After doing some tests, it has something to do with the resolution / position of the STL files that are being morphed.

The current Mandatory part STL looks like this, and is causing the positional issues that we have all been reporting :



If you remesh and re-export the STL to look like this, the results are much more acceptable. Still not perfect, but the discrepancy with our suspension parts is much much smaller.



Please test that for yourself, but maybe that could be an alternative short-term solution to consider whilst you figure out what is really going on with morphing.

[CAEdevice]

@G-raph, I confirm: it looks that the final position of the inner arms is sensitive to the mesh resolution and quality.

[LVDH]

Looking at how the morphing works, I am actually a bit surprised, but thank you very much for this finding. I will investigate deeper after this race.

As mentioned before, I would be in favour of removing the internals parts for that race when covers have been submitted. In case not all suspension members have a cover, Yinlad's solution should be recommended.

Yepp, this is the pragmatic way to go for this race. That is what I will do.