Endurance Oreca 07 lift to drag ratio

Discussion in 'General Discussion' started by avenger82, Jun 19, 2018.

  1. Kevin Ryan

    Kevin Ryan Registered

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    Maybe I'm thinking about it wrong, but if this were true would it not be really obvious that the sim car doesn't behave like the real car. I mean if the drag is too high then the car should be going much much quicker in a straight line. If the lift is too low than the car should be going much quicker through the corners.
     
  2. mclarenf1papa

    mclarenf1papa Registered

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    The drag is totally fine for all variants of the car. The downforce is correct on the low-drag package; on the standard package it's not. Even without looking at the telemetry, the low-drag configuration is 2 seconds per lap faster around Sebring. It's making essentially the same downforce for much less drag than the "standard aero package" trims. The L/D of the low-drag package is around 5:1, while the others are all around 3.5:1.

    So yes, the car (besides the low drag variant) should be going much faster through the corners.
     
  3. UsedMomo

    UsedMomo Registered

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    I wonder how easy something like this is to fix. If it's as simple as entering different values in a file, then there's no excuse why it can't be patched quickly.
     
  4. mclarenf1papa

    mclarenf1papa Registered

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    It'd be a parameter issue, yes. But that doesn't mean they wouldn't have to test it to ensure it works correctly. Additionally, aero's fairly complicated and if it's more than just a simple typo, it may take some time to amend.
     
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  5. Marek Lesniak

    Marek Lesniak Car Team Staff Member

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    Thanks guys for the feedback. There's a mistake in aero of the front dive planes, and we are also looking again, if there's anything else to fix. So yes, there will be an update to the car.
     
  6. avenger82

    avenger82 Registered

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    Great, it's good that you found the cause and are looking for other things that potentially would need to be fixed before releasing the update. Maybe other cars also have some issues. I think it's better to take your time not just do quick fix without re-testing.
    BTW: Do you have real telemetry data from team(s) to compare with rF2 output? I know that's how issues OR discrepancies in GP3 mod were discovered it was tuned .

    Also thanks to @mclarenf1papa for investigating and providing necessary information.
     
    Last edited: Jun 27, 2018
  7. liakjim

    liakjim Registered

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    Looks like the " I will not tell you my perfect set-up" guy , owes an apology ;)
     
  8. SPASKIS

    SPASKIS Registered

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    Yes @Devin seemed to want to maintain the "low aero upgrade" trick to beat those who would think that standard package would better suit most tracks.

    After accusing of providing false information he disappeared without admitting his error.
     
  9. avenger82

    avenger82 Registered

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    Why would he? He and people from Discord are right and S397 is just wrong ;) He has prove for it, but unfortunately cannot share neither his confidential setup nor telemetry logs /s
     
    Last edited: Jun 29, 2018
  10. Devin

    Devin Member Staff Member

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    Little do you know but on discord @mclarenf1papa , @Slamfunk3 and me actually discussed that topic for hours, gathering motec logs, analysing the crap out of the issue and trying to come to a conclusion what exactly went right and what went wrong. I am generally not active on forums, especially if something already gets discussed with the people who are actually responsible for it, and obviously they were on discord as well.

    The conclusion: HDF has a lower L/D than LDF by quite a margin, but the claimed 3.1 L/D ratio is still incorrect because even with the HDF upgrade I got it up to almost exactly 4.0, and with LDF I get it up to pretty much 5. On a close to default setup it was already 3.7. While this clearly shows that there seems to be an issue, it also shows that the provided info isn't necessarily the full truth to it. We even discussed the possibility of it being intentional or even realistic based on data from older LMP2s, but came to the conclusion that the HDF upgrade simply looks to lack additional downforce for some reason and is now obviously being looked at for that reason.

    Also great job immediately accusing someone of cheating just because an upgrade that would normally not be used on certain tracks turned out to be faster on them anyway. I had my logs from preparation for GTR24h, so I recorded them at le mans, where that upgrade is the obvious choice anyway. I haven't even done any logs on other tracks as I never had a reason to develop decent setups on those anyway.

    @avenger82 if you could actually read, or if you had spent literally 10 seconds actually informing yourself about the issue instead of spamming literally everywhere about it existing without any evidence, you would've seen that I actually provided screenshots to logs on discord, as well as doing the math myself on it from a separate setup that I made specifically for this occasion. Your general style of typing seems to indicate that you're the same guy who mindlessly spammed the rF2 discord about the same thing recently, and while on Discord it's debatable, here you're simply starting to derail a forum post again and again, trying to start fights. I must warn you, because here it actually leads to a warning, followed by a ban if you don't stop. This place is about discussing certain topics constructively, and you are making that unnecessarily hard, even for the people who you claim to support.
     
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  11. SPASKIS

    SPASKIS Registered

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    I really don't care about what happened on discord since the discussion was taking place here.

    There was a clear error which was reported and in a first instance you denied it and was proven an error.
     
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  12. UsedMomo

    UsedMomo Registered

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    Do the configurations with only upper or lower dive planes, or no dive planes have the same problem?

    Also, which is the higher downforce option in real life -- only upper or only lower?
     
  13. avenger82

    avenger82 Registered

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    @Devin - Why (instead of typing all this) just admit you were wrong and baselessly tried to discredit @mclarenf1papa?
    LOL it's good you are not admin here.
     
  14. mclarenf1papa

    mclarenf1papa Registered

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    To once again address some things that need clarification, I don't know if Slam and Devin discussed it on their own, but my Discord involvement consisted of me backing my "unrealistic claims" with regards to the work I've done in the past, Devin doing a test and writing that he got a 3.8 L/D with the HDF setup (no screenshots), Slam bringing up some 2010 data that, while interesting, wasn't particularly relevant (and also made little sense when compared to all of the other LMPs I've worked on), and then me running brief tests on the rest of the aero packages. Nothing more transpired than that...

    Anyway, as I said, the issue affects the "standard aero package," which encompasses every trim besides the low-drag configuration.

    My provided info was correct. With a realistic setup using the default aero configuration, the L/D was 3.3-3.5 (if you look at peaks; my data showed that), which is too low. You can get a higher L/D than that by running additional rake (that would ruin the balance IRL and likely once the car is updated in RF2), but that's not strictly relevant and it is, in any case, lower than real life.
     
  15. Stefan_L_01

    Stefan_L_01 Registered

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    Because it is about telemetry: for the new RSR I found that in the garage, sum of tire load matches weight. At 250kmh, the increase of sum in tire load does not match the sum of downforce
    So something is off with downforce values or with telemetry values
     
  16. mclarenf1papa

    mclarenf1papa Registered

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    o_O

    1. When I checked that exact thing on the Oreca, the difference was negligible.

    2. A developer confirmed that the car has an issue a few posts ago...
     
    Last edited: Jul 3, 2018
  17. SPASKIS

    SPASKIS Registered

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    Can you provide a picture of those results?
     
  18. Stefan_L_01

    Stefan_L_01 Registered

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    Just make screenshots yourself with rfProject , Basic belt "cardata", easy to see.
    It´s not that much, RSR Maybe 150N difference. Radical GT3 300N. Both gain more Wheel load than downforce what is strange, because if you think About Camber and force vectors the load may split up into vertical and lateral/Long, but then the vertical Vector should be less than the downforce Vector. But the Bently: 500N difference, but MORE downforce than raise in tire load. It just misses any logic for me, but probably you Need exact Knowledge of Vector orientations
     
  19. Lazza

    Lazza Registered

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    @Stefan_L_01 I would suspect it may be partly due to you assuming front and rear downforce are something akin to a front and rear axle measure of generated downforce, when the front and rear downforce may actually be limited to what is generated by wings/spoilers. The effects of body aero, fenders/flickups, and diffuser may not all be included in those figures. In fact the discrepancy you're seeing may itself be something of a measure of those extra components' aero effects. It's also possible the downforce figures are measured far enough from the axles to have positive or negative leverage, further throwing the reported figures away from what you're expecting.

    Obviously I'm not totally sure of this, I just think it may be a factor.
     
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  20. Comante

    Comante Registered

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    Unless point of application of aerodinamic forces is perfectly above the tire, there will always be discrepancies , as you must take into account that offsets in vectors induce a rotation, throwing the wing load in another direction, vectorial sum is then different from arithmethic sum.
     

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