EuskoTestTrack

Discussion in 'Locations' started by SPASKIS, Nov 26, 2017.

  1. FuNK!

    FuNK! Registered

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    That's really cool! I wanted to create a loop for testing but never had... :D
    Overall it's a great track for testing too :cool:

    One suggestion for the loop: It feels like the transfer from the vertical part to the upper edge is too edgy. Sometimes it slows down your car so you can't take the full loop. Maybe you could have a look how the looping looks like in this video?

    Above this, would you be interested in adding some of the features the Test Pad track from Stereo for AC has? e.g. collision measuring.

    Anyway thank you very much for your work ;)
     
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  2. SPASKIS

    SPASKIS Registered

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    I know the loop has that problem. It is because I had to fix a problem that impedes doing it properly in BTB. After having doing it once next time I will probably improve the way for doing it.

    For the moment it makes it more tricky to correctly take the loop.!!!

    I will start implementing a small surprise for Formula 1 fans asked by kne of my mates from RaceRfactor. I have to do some calculations and telemetry checks first. You'll see the results soon.

    For the part regarding other tests please make a list with a brief explanation. From the suggestions for example, the eight shaped track, will not make for the moment. I don't see much utility to it.
     
  3. Skan

    Skan Registered

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    Something keeps whispering "drive the boxmaster and the Dallara F1 at that track" and the occasional yells of "787B and D4" are getting to loud to ignore. The 1/5 scale RC car...that little thing needs to play at the test track. Go Karts on this track would be better than laser scanned nords. Oh... a wish list...

    It is a fantasy track so go all out

    A tube that we can drive inside of, preferably the length of the track but suspended as high as possible with only one way in and one way out.

    More loops and loops of various widths.

    Loops with no middle connection...as in an upside down jump.

    a corkscrew loop because those are crazy
    the track does this... https://thumbs.dreamstime.com/z/twisted-rollercoaster-track-15004297.jpg
    while doing the loop.

    vertigo inducing high banks on 2 turns

    2 ramps specifically to perform barrel rolls

    Things we can hit that keep moving such as a ball

    a parking garage with parking spaces to park or whatever other fun we can make from that. Parking competitions for example.
    http://assets.inhabitat.com/wp-content/blogs.dir/1/files/2010/11/Greenest-PArking-Lot-1-600x369.jpg

    Gymkana type car control testing areas.
    http://a.espncdn.com/photo/2013/0804/Gymkhana-Seq_sized.jpg
    https://img.gta5-mods.com/q75/images/gymkhana-v/1238b6-Untitled4.jpg

    A car wash. Do not say you don't want one. The cool kind with the spinning brushes flinging soap all over the place.
    https://upload.wikimedia.org/wikipe...Road,_Warwick_-_geograph.org.uk_-_1204540.jpg
     
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  4. SPASKIS

    SPASKIS Registered

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    Can some car modder confirm if aero values for downforce always apply the force in Z direction regardless of the position of the car?
     
  5. SPASKIS

    SPASKIS Registered

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    There is no need to confirm it. Telemetry did. I found deceleration values when going uphill reaching almost 2,4g (24m/s2). Gravity and drag cannot provoke such a huge deceleration.

    I just saw that, as I suspected after some tests, downforce always points in the track Z direction. It should point at the car Z direction but it doesn't.

    I was trying to make the car driving on a inverted road thanks to downforce but it is impossible.

    This flaw also affects the normal loop since the car gets dragged by downforce when pointing up.

    The biggest effect in normal tracks is a slowdown provoked by downforce when the car is driving up a slope.

    In Spa's Eau Rouge, with over a 10% uphill, a Formula1 with a 2g downforce would suffer an over 0,2g deceleration caused by this.
    The normal acceleration of a F1 car at 250kph speed should be around 1,5 g so the acceleration reduction is around 15%.
     
    Last edited: Nov 29, 2017
  6. SPASKIS

    SPASKIS Registered

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    I made a small correction. The motec channel for acceleration had wrong units. It provided a 3,6 times higher value.

    Corrected values are more consistent with the theory that downforce points always down regardless the car position and inclination.
     
  7. Skan

    Skan Registered

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    Please use the 1/5 scale R/C car for your next upside down test. I'm not saying it will work. I'm not questioning this test. I just don't have the same track as you so I cant mess with the car is all. Someone should be having fun with it. You are going to make me get you an .fbx file of some type of aircraft...this is a test track after all.
     
  8. JuanitoRPM

    JuanitoRPM Registered

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    And what happen with this effect in a banked curve? The downforce applies down and the car is inclinated?
     
  9. SPASKIS

    SPASKIS Registered

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    Tire Load at 0 kph: F: 1620 N R: 1930 N (static tire load)
    Tire Load at 230 kph: F: 3550 N R: 4750 N (in the straight prior to ascending)
    Tire Load at 230 kph: F: 2200 N R: 2700 N (inverted in loop)
    Downforce at 230 kph should be enough to sustain the car downwards since it more than doubles static tire load.

    I'll try the banked track and check for lateral effects after dinner.

    upload_2017-11-29_20-50-46.png
     
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  10. SPASKIS

    SPASKIS Registered

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  11. Oddonis

    Oddonis Registered

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    Fantastic. Thanks , you could do like a stunt track in the near future..
     
  12. Raintyre

    Raintyre Registered

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    >>>>>>Can some car modder confirm if aero values for downforce always apply the force in Z direction regardless of the position of the car?

    I don't think so. If you obtain high deceleration values when going uphill it may be due to other combined effects.
    If downforce pointed always to down then the car on your video would have fallen inmediately and violently and probably wouldn't have arrived to the top of the loop, pushed by its weight and downforce together. However we see it stands for some meters and then starts to fall softly.
    I don't know the reason why it didn't resist there, perhaps any other issue, .. i will try myself with other "aero-cars". Nice test track, by the way, thank you!!
     
  13. SPASKIS

    SPASKIS Registered

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    I did some further tests and I concluded that downforce didnt go in pure z direction.
    I am still trying to figure out what is happening when car gets vertical and the sudden change in deceleration. It seems that some force is reverting at that point but I am not sure which. I need to do more tests.
     
  14. SPASKIS

    SPASKIS Registered

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    I would like to do some further research first in order to be more specific.
     
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  15. SPASKIS

    SPASKIS Registered

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    Going back to the test track....

    I tried introducing different types of curved loops but I was not happy with the result.
    It is not easy to find a smooth banking angle transition so that the car drives smoothly.
    Therefore, I have decided to abandon the trial and error design method and substitute it by something more analytical.

    I am creating an Excel file where I can define any type of 3D path based on the in plane and helicoidal curvatures where I can later analyse the loads acting on the car in different scenarios (accelerating, braking, constant speed...). I wil be able to make smoother transitions and correctly define the required angle for the banking.

    I have already finished the centerline drawing algorithm.
    I have also included the 4 typical 3D projections to properly see the result.
    Next step is to represent the lines defining the cross sections of the road.
    Later I will calculate and plot main loads at different points.

    Once everything is finished, I will split the track into different segments defining how both in plane and helicoidal curvatures evolve through each of them. Adjusting the values will be just a few clicks once the conceptual geometry is defined for each segment.
    upload_2017-12-6_4-7-29.png
     
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  16. davehenrie

    davehenrie Registered

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    yeah....what he say....I TOTALLY concur......


    errrrr......
     
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  17. Raintyre

    Raintyre Registered

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    I did some tests on dev mode. I had to add insane downforce to my vehicle, but finally achieved to drive upside down, sticked to the inverted road at around 260kph.

    Regarding the climb on the loop, I didn't observe a sudden deceleration when climbing the loop. It was progressive deceleration, which i think it is a natural thing. We carry all energy on a certain axis (for example X axis before the climb) and we want to convert all the energy to the z axis (when the vehicle is vertical). The price to pay is that a portion of the energy is lost in the process.
    A loop road is in fact a obstacle, but softened. The more pronounced is the slope, the stronger the vehicle will be pushed against the road. That will mean a big increase on friction forces and perhaps also extra aerodynamic drag due to low ride heights or unbalancing,...
    Then we have at least gravity force, frictions, and perhaps aerodynamics issues making extra oposition. A big deceleration should be expected, i can't say how much, but not a tiny thing.

    It happens the same when cornering on flat road. Acceleration on a big corner is never the same as it is on pure straight, because part of the energy is lost as the vehicle fights to change its orientation.
    Also, if you drive a big oval circuit, you will observe that the vehicle accelerates easier at the straights than on banked corners. Even if you don't have to steer to drive in the bank (no lateral loss), there will be a loss on the vehicle's x axis. The car "wants" to "go through" the road to follow a straight, but it is forced to do a curve on the space.

    Apart from possible bugs on the vehicle or the road, i think what we see is physically correct, at least on its concept.... anyway, i am not engineer !
     
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  18. SPASKIS

    SPASKIS Registered

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    I realized that I have probably neglected the drag effect when being face down. The remaining tyre load was not enough to provide the required traction. That's why you need bigger downforce to overcome drag.

    Regarding the issue when vertical. You are wrong when saying that the higher the slope, the greater the vehicle is pushed against the road.It increases with curvature and decreases with slope.

    The fact that tyre load keeps increasing until it suddenly decreases is for sure a weird problem.

    My spreadsheet will show these things when ready. I will draw the circuit that I used for that test and we will see what it says. It will be a nice benchmark to check for errors in the spreadsheet.
     
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  19. Raintyre

    Raintyre Registered

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    >>>>The fact that tyre load keeps increasing until it suddenly decreases is for sure a weird problem.

    There are some parameters on vehicles aerodynamics that could contribute directly to extra drag, or trigger undesired chain effects on special situations. For example:

    BodyUp=(0.0, -0.50, -0.30) // aero forces from moving up

    If second or third values were too big, your vehicle will be added a lot of extra downforce and/or drag.

    Same thing with other parameters :
    BodyRot=(1.1, 1.2, 1.0) /// (Add forces depending on rotation)

    Those are random examples, I don't know what are your vehicle hdv parameters.
     
  20. SPASKIS

    SPASKIS Registered

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    I pretty much finished my spreadsheet. I hope an image is worth more then words here.
    As you can see I have recreated the loop case where the car would fall when reaching te top of the loop.
    You can also see how normal force (tyre load) should be behave when going up the loop.
    I put together telemetry and analytical results and as I said in previous post, normal force should decrease but in rF2 increases.
    @Michael Borda Do you have an explanation for this?

    upload_2017-12-7_3-41-14.png
    upload_2017-12-7_3-42-48.png
     
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