Oreca 07

Discussion in 'Technical & Support' started by Earthling, Feb 8, 2023.

  1. Earthling

    Earthling Registered

    Joined:
    Feb 8, 2023
    Messages:
    16
    Likes Received:
    3
    Hi all, It could be that am missing something so i've created an account in order to pose this question about the Oreca 07.
    I used to race a lot on Rfactor1 years ago and have now just started with Rfactor2 after enjoying the 24 hours of Lemans race.
    Though i'm old, i've not lost my competitive spirit and thus have been busy to setup the Oreca 07 in order to clock some good laptimes at the Lemans circuit.
    But here is my question, while working on ride height i noticed that it doesn't seem to matter if we add packers or not in order to prevent bottoming of the car, the ride height does not change unless i change the ride height itself but that should of course be as low as possible.
    So hopefully someone can help me with the answer. :)

    Ohh and a huge thumb up for the team behind the development of Rfactor, it really is a joy to drive and looks fantastic.
     
  2. davehenrie

    davehenrie Registered

    Joined:
    Jul 6, 2016
    Messages:
    7,537
    Likes Received:
    4,434
    The Oreca has always had a floor dragging issue at very high speeds. Like from 315kph+. Compare that to the Ligier LMP2 which was created by a different group/individual. So for the Oreca you need really stiff springs more than packers & a few mm more ride height than the ligier.
     
  3. Bernat

    Bernat Registered

    Joined:
    Jun 15, 2020
    Messages:
    786
    Likes Received:
    613
    Take my words with a grain of salt because I don't have much knowledge about setups, but I think ride height in the setup is the final ride height after taking into account all the other variables. So you first set the ride height you want then change packers, etc., and the ride height will be maintained as far as it's possible.
     
  4. Earthling

    Earthling Registered

    Joined:
    Feb 8, 2023
    Messages:
    16
    Likes Received:
    3
    Thanks for the reply, i could go one click higher to stiffen the springs at the rear if packers don't change anything. :)
     
  5. Earthling

    Earthling Registered

    Joined:
    Feb 8, 2023
    Messages:
    16
    Likes Received:
    3
    As i understand it, packers reduce compression travel of the springs and thus results in higher ride height at high speed which allows us to lower the car through lowering rid height (lower center of gravity) which is favorable. :)
    Those packer though do not seem to do anything. :)
     
  6. Booth_doberman

    Booth_doberman Registered

    Joined:
    Oct 5, 2015
    Messages:
    187
    Likes Received:
    84
    Have you looked at the ride heights data in Motec? I ran the Orecas a week or so ago at LeMans, and I don't recollect Motec showing anything hitting 0 height. Of course, I could be interpreting the data incorrectly, too.
     
  7. Earthling

    Earthling Registered

    Joined:
    Feb 8, 2023
    Messages:
    16
    Likes Received:
    3
    i could be wrong maybe, have to look at the suspension if travel changes
    Yes i did, 20 mm should be considered 0 :)
    Go below 20 mm and you'll hit the tarmac.

    I just did a few testruns with softer springs (800) at the rear, one with packers to the max and another another testrun without any packers for comparison.
    Of course due to softer springs the ride height is lower so be careful when approaching Indianapolis, the suspension travel nor ride height are affected by the packers, though i seem to notice it when driving, more roll and thus more easy through slow corners it seems. :)
    I thought that maybe 1100 at the rear would be to stiff for the compression travel to be hitting those packers but that is not the case.
     
  8. Booth_doberman

    Booth_doberman Registered

    Joined:
    Oct 5, 2015
    Messages:
    187
    Likes Received:
    84
    Would you explain why 20mm should be considered 0. Is that true for all cars or just the Orecas?
     
  9. Earthling

    Earthling Registered

    Joined:
    Feb 8, 2023
    Messages:
    16
    Likes Received:
    3
    because lower than 20 mm means that the car is bottoming out, hence that should be 0 instead of 20.
    Don't know if that is the same with other cars, have only been driving the Oreca. :)
     
  10. Booth_doberman

    Booth_doberman Registered

    Joined:
    Oct 5, 2015
    Messages:
    187
    Likes Received:
    84
    How did you determine it was bottoming out at 20? Did you view replays looking for sparks or did you turn off all other sounds and listen for it? Or is there another way to tell? I guess you could do a setup and just run down one of the long straights and look for sudden time drops.
     
  11. Earthling

    Earthling Registered

    Joined:
    Feb 8, 2023
    Messages:
    16
    Likes Received:
    3
    Sparks revealed it, when i was approaching Indianapolis. I spun out there because of it, after raising the rear ride height no problem anymore. :)
     
    davehenrie likes this.
  12. Simulation_Player

    Simulation_Player Registered

    Joined:
    Mar 4, 2022
    Messages:
    707
    Likes Received:
    449
    @Earthling Did you check if u are actually riding on bumpstop or not ? although with MAX packer you should be running on it but just in case see if susp force increases exponentially as susp travel increases.
     
  13. davehenrie

    davehenrie Registered

    Joined:
    Jul 6, 2016
    Messages:
    7,537
    Likes Received:
    4,434
    I never discovered the 20mm, but I did use Le Grand Circuit and found it stalled at about 318kph where as the LMP2 ligier could get up into the the 320s. Counter-acting the downforce requires at least stiffer springs than the default settings.
     
  14. Earthling

    Earthling Registered

    Joined:
    Feb 8, 2023
    Messages:
    16
    Likes Received:
    3
    I did this little test yesterday, 1 run with packers (full amount at the rear) and 1 without.
    For this i did set the rear springs at 800 but i could try the lowest setting. :)
     

    Attached Files:

  15. Simulation_Player

    Simulation_Player Registered

    Joined:
    Mar 4, 2022
    Messages:
    707
    Likes Received:
    449
    looks like u got data , can u do a scatter plot like this :

    https://forum.studio-397.com/index.php?attachments/fpro-png.43521/

    This way it is readable , more focused. you already have data , just need to make a new scatter plot.
     
  16. Earthling

    Earthling Registered

    Joined:
    Feb 8, 2023
    Messages:
    16
    Likes Received:
    3
    I would have to learn how to make such a scatterplot. :)

    Though i think it is now also somewhat visible in the image below, higher suspension force when travel has reached its limit?
    With the softest spring setting it seems to be fully compressed at speed, white is without packers and colored with packers but again no difference in ride height.
    A slight difference in suspension position when looking at the image but it is very little though there is an obvious change when looking at the suspension force.
     

    Attached Files:

  17. Simulation_Player

    Simulation_Player Registered

    Joined:
    Mar 4, 2022
    Messages:
    707
    Likes Received:
    449
    yea still not readable, i also don't know which colour is one with max packer and which is not.

    scatter plot is very easy to do, in motec create new workspace or new tab.......whatever it is called. then right click it will show you scatter plot option, then you simply put susp force and susp pos channel in there. fiddle a bit , you will find it for sure.
     
  18. Earthling

    Earthling Registered

    Joined:
    Feb 8, 2023
    Messages:
    16
    Likes Received:
    3
    Hopefully i did it right. :)
    Green is a lap with springs at 800 and packers added.
    Pink is a lap with springs at 650 without packers.
    White is a lap with the springs at 650 and packers added.
     

    Attached Files:

    Simulation_Player likes this.
  19. Simulation_Player

    Simulation_Player Registered

    Joined:
    Mar 4, 2022
    Messages:
    707
    Likes Received:
    449
    Nice work mate, appreciate it.
    from your description we should only focus on pink and white color ones. since spring rate is constant with only packer/bumpstop difference.
    so looking scatter plot , around 32mm the white line goes straight up....probably because it is hitting bumpstop hard. While pink one goes slightly ahead still to 33-34mm. the pink one looks pretty linear even till the end of travel so most likely not hitting bumpstop.

    looks like you are hitting packers/bumpstop a bit late , was white run (650 spring with packers) done with maximum packer ?
     
    Earthling likes this.
  20. Earthling

    Earthling Registered

    Joined:
    Feb 8, 2023
    Messages:
    16
    Likes Received:
    3
    Yes, it was done with maximum packers. :)
     

Share This Page