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

[G-raph]

Congratulations JJR for another win, and nice to see Koldskaal back on form and another rookie on the podium!

As anticipated there was some big development steps achieved all around, so considering how far behind I am with my 6 CFD runs, I am relatively happy with 4th place.

Interestingly, whereas in previous years there was a massive performance gain on all aspects from the FAST template to the official simulation, this years the numbers look very comparable. If anything, official results are now slightly worse (for me at least) : +0.04Cx ; -0.04Cl ; +0.04CoP ; -0.1Cooling.

[LVDH]

I have finally posted the results:
https://mantiumchallenge.com/results-mvrc-monaco-2025/
This includes scrutineering results.

First of all, huge congratulations to JJR. He is back and looks like he is on a mission.

And as always, a huge thank you to the MVRC staff. Once more we (mostly) did a great job behind the scenes.

Not only the staff and me put a lot of work into this championship. Also the teams, esp. those on top put huge amounts of their spare time into this crazy championship.

I know this very well and because of that the championship should be enjoyable for everyone.
In this and also in the previous race CAEdevice obviously did not have that much fun. Other teams are also not happy about everything. I am also not 100% happy with everything either and will improve certain aspects soon.

I put more thought into the CAEdevice submission in this race and see it like this: It does not matter why his simulation failed. It failed because of a part that was submitted. This has happened in the past and the teams were classified as DNF. Because this has happened in the past it has been codified in the sporting regulations (1.6). That rules does not speak about non-water tight geometries. It is just about CFD simulations failing. The last case I remember, was about some strange porous media geometry. The team then had a DNF because the simulation did not work. So this stuff has happened in the past and was handled just like this time. A team submits geometry that does not run through the CFD process and gets a DNF as result.
And while this is not enjoyable for a team that receives a DNF like this, it is not enjoyable for me to fix crazy problems. And even if I was fine with fixing these things in the past (and I have been for many years), it is simply not possible any more because there are too many cars now every race. And that is exactly why the rule was introduced.

Then when I hear: "I cannot win the championship anymore, so I am out", I am a bit surprised by the attitude. Yes, maybe you think the championship is over, but you can still compete go for victories and learn something. Maybe learn what is needed to go for the championship next year? I am sure that JJR has not won every MVRC race and I am sure he has failed at other stuff. But he did not give up and learned, which is showing this year.

Regarding correlation issues:
You guys can always send me your reports and complain about results. I then look into them. So far, every time I have seen that the team had other geometries in their simulations or used their own settings.
MVRC has to run simulations that balance realism and keep computing requirements reasonable. There will be no perfect balance. But if what we do is asking for too much then consider this:
Yes, I am now doing an MbS: When I competed in KVRC, I possibly had the most computing resources of any team. Was it enough for me? No, I had way more ideas than computing time to test them.
So what did I do? Well, I created my own settings that were fast and could figure out if a part was better or not. Then every N simulations go for a full run to make sure not to drift off into a fantasy world. Everything that has to be done in MVRC is create the best parts, that is all. If you do it like this, you have a good chance of creating the best car you are able to. Sometimes I would even stop running simulations, when I would see that the forces do not seem to be where the should at n iterations compared to a reference simulation. That your simplified / fast simulations then do not match with the official results does not even matter.
Running modified settings or not 5000 iterations and then complain about results not matching up does not make any sense to me.

At least with the CAEdevice situation, there is a very nice light. I really like the idea of the Ahmed Body of MVRC. This is a fantastic idea and I am looking forward to running it.

I am looking into some modifications to MVRC. I am already pretty sure on one modification:
Scrutineering results will get posted on Monday. The teams can then protest the results. Delayed submissions will not have the possibility to protest. Then, I have some smaller ideas, that I will think about during the weekend. Because of this, there is a good chance, I will delay the next race. And next week, there will be a new MFlow version that fixes some small issues, like the incorrect turbulence model on the tires.

[CAEdevice]

At least with the CAEdevice situation, there is a very nice light. I really like the idea of the Ahmed Body of MVRC. This is a fantastic idea and I am looking forward to running it.

It is almost ready.

I had to tweak the balance to provide a realistic car.

I will provide the simulations (fast/standard/long) with the present MFLow version, but in case of a new version of MFlow they should be updated.
The car will run every race as a "ghost car", only as a reference.

[CAEdevice]

PS: "I cannot win the championship anymore, so I am out", who said/wrote that? Not me.

I wrote something different.

wrote that with an unfair application of the rules (first race) and an inconsistent one (second race, where I did make a mistake, but it was handled arbitrarily), the motivation to invest time in gaining those few newtons of downforce fades, especially when I haven’t seen them reflected in the official numbers twice now.

As for the championship, judging by the competitivness of the car, would not be completely over yet ... but I need a regenerative break after too many night spent on the ruled volimes and on the design of my car. The Monza project (completely new car) and the Ahmed Car idea are both very interesting.

Finally, the decision to complete the scrutineering BEFORE the simulations is wise.

[CAEdevice]

Regarding my involvement in the staff.

I’ve come to the conclusion that being part of both the technical staff and competing as a participant is too demanding and complicated. I therefore confirm that I will remain on the team solely for marketing and social media activities.

Any technical contribution or proposal from CAEdevice (es. Ahmed car) will be published here, publicly.

In particular, I will continue managing the LinkedIn page, as I did for the Monaco event, it felt right to celebrate the teams on the podium. It would also be great to improve the website.

As for sponsorship, the matter is a bit different.

I sincerley apologize for any disappointment, and I confirm that I will still provide a small prize. The disappointment, as a sponsor, also stemmed from the uncertainty surrounding the results of the first race (CoP, steps, rules postponed, the management of my specific case …). In the second race, aside from my own case, things were going better, even if some aspects were a bit approximate, but not from a technical point of view.

That said, I truly hope more sponsors will come on board, as I believe it's essential to be able to compensate the time of those who handle and review the simulations, and to support a minimum of event-related activities (such as motorsport or cfd meeting attendance, an annual MVRC meeting, etc.).

[yinlad]

PS: "I cannot win the championship anymore, so I am out", who said/wrote that? Not me.

I wrote something different.

wrote that with an unfair application of the rules (first race) and an inconsistent one (second race, where I did make a mistake, but it was handled arbitrarily), the motivation to invest time in gaining those few newtons of downforce fades, especially when I haven’t seen them reflected in the official numbers twice now.

As for the championship, judging by the competitivness of the car, would not be completely over yet ... but I need a regenerative break after too many night spent on the ruled volimes and on the design of my car. The Monza project (completely new car) and the Ahmed Car idea are both very interesting.

Finally, the decision to complete the scrutineering BEFORE the simulations is wise.

He is referring to me. But it is also not what I said. I do believe the championship is already over though and the points structure we use does not suit only 5 races per year.

For me I simply do not have the time to put in the work to solve my correlation issues while trying to improve the car sufficiently to be competitive. Me shooting myself in the foot with a dumb penalty that is nothing to do with car legality Is just the cherry on top.

But more importantly the process above would not be enjoyable, so why spend so much time on something that will only frustrate me? This is a hobby at the end of the day.

Secondarily, and this is not the fault of MVRC, these regulations are not that interesting compared to last year.