Oreca sparks occur without the floor touching the ground

This I have noticed on the daytona straight and banking. Its consistently showing sparks, even though the floor is clearly not touching the ground. I have only tested the oreca (TEST) with this. So not sure if its a car issue (looks like there is part of the model touching the ground, as raising the car gave me significantly more top speed), or the sparks get created too early.


V1128

 

The floor is defined in the physics (HDV) file, not by the graphics. Perhaps the graphics need adjusting, it's probably more likely than the undertray points being wrong (though you never know).

 

I am checking this, but it looks like the car is actually bottoming, with no part of the model touching the ground. In white the ride height is changed from default to 8CM in the rear, packers set to 2CM in both. The screenshot in main post is with the default ride height. So this looks to me like a model issue more than a spark point issue

 

As I said on discord, the sparks also seem to be coming from the middle rear part of the floor. If it is the diffuser touching the ground, you would expect one of the sides to hit it first, not the middle. Maybe something is sticking out in the model there?

 

https://www.fia.com/sites/default/f...p1-lmp2-bodywork_deflection_test_22072019.pdf

It looks like lmp2 cars have skid blocks on underbody.
If it is sufficiently lower than the diffusor edges themselves then it may explain why sparks only come from middle.

 

thats 5MM though, the car is much further off the ground than that. On top of that, that would mean the skid block isn't modelled, and on top of that, what are those skid blocks made off?

Edit; Found out that the skid block is 2.5 cm new, with 5mm allowed wear.

to add to that, I have looked at the technical drawings, and where it should be on the underbody, it is visually not touching the ground

 

Steel, Titanium. I can remember from back in the 90's they said magnesium.

Theres a parameter in the .hdv file to shift graphical model a bit without affecting physics:
"GraphicalOffset=(0.0, 0.0, 0.0) // does not affect physics! This just moves the vehicle body for whatever reasons you may have."

 

@Remco Majoor the graphics are off. Maybe the body is slightly higher than it should be, maybe the undertray points are slightly lower than they should be, maybe there should be a skidblock under there that you can't see because it's not there. You can see a gap, therefore there is a gap, but the physics are touching, hence the sparks.

It doesn't matter what anything is made of. If an undertray point hits the ground, there's a spark.

I don't know what else you want. Something isn't right, and that's it.

 

Just simply trying to educate myself about what I am reporting, so I know what exactly the problem is, rather than just guess. Unlike a lot of people I tend to like to know where I am talking about, when I am talking about it.

 

My point about skid block was regarding sparks only coming out of middle part.
Graphically it looks odd , you are correct about that.
IRL skid blocks are made of wooden looks plank and titanium(or other metals) placed in specific locations in it.

https://upload.wikimedia.org/wikipe...a_RC-F1_2.0X_bottom_Honda_Collection_Hall.jpg

 

That's why I talked about the undertray points in the HDV in my first reply. They are completely disconnected from the car graphics - you could have the car 3ft in the air and those points still hitting, or you could (to some extent) have the graphical body buried in the track and the undertray points not touching (there seems to be some crossover there, but I don't think it's an advised design route for modders).

I'm actually a bit jealous, because games become a bit less magical when you gain an understanding of how they work.

 

It does indeed make sense that they come from the middle. I am not sure how with so much ride height added, I am still bottoming though. But for that I need to test a few things more and ofc check some IRL footage of LMP2s at Daytona.

 

The magic is then replaced by respect and awe, It is always fun (for me atleast) when you brake down on what's actually happening.
Recently i watched a video on how a certain cutscenes is made in a dark souls game.
in cutscene it looks like the character is growing BUT in reality the entire arena shrinks !
mind blown, totally unexpected.

This is the video (if anyone is interested) >

 

At 8cm RH you gained like 3.5 to 4mm height compared to default.
(if this what your motec screenshot is about).
That is not a huge gain IMO, i think there are levels of scraping the ground in rf2.
for example if you are hitting the ground at say 50mm then you can still go lower to say 53mm.
Ofcourse there will be a point where you are scraping the ground too hard/too low , then RH won't go any lower.

 

and in the setup I raised the ride height by 2 CM, which means I am bottoming

 

The Oreca07 has an offset in the physics due to maybe something else bottoming before the ride height, so you will start grounding when the ride height in the telemetry is around 25 mm. IIRC, it's the same for both axles.

 

Even with the highest ride height in the rear.

It doesn't seem to be bottom the front axle for me as far as I can see. But the rear axle definitely has something

 

are u running into packer/bumpstop on front axel ? that could prevent front from bottoming out, if they are at high value.

 

iirc, the oreca rear suspension has motion ratio of around 3.... front is around 1
so if you are using a low spring rate in rear, even the higher ride height could still bottom out with high aero load (downforce)

try your test with higher rear spring rates to keep rear from bottoming

 

That motion ratio of 3 to 1 at the rear, is it at the real car?
I compared "suspension position" with "ride height" channel output in the sim and it lokks more like 1 to 1 on both axle.
Of course assuming here "susp pos" is taken at damper attachment, so after pushrod and rocker. Couldn't find something like "damper pos".