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Cherrier Vivace & Tograc

Discussion in 'Official Content' started by Falkrum, Feb 12, 2020.

  1. default0.0player

    default0.0player
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    Does the CR-V also do that in reverse gear?
    The clutch is between the engine and the gear, thus given the same engine torque the stress in 1st and other gears are the same. Also the turbopetrol Vivace Arsenic has higher torque(even at lowrpm) than the diesel used in the Tograc, while using the same AWD transmission. The only reason to reduce power on lower gear is to reduce wheelspin on 2WD vehicles.
     
  2. Rubidium

    Rubidium
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    I don't know if it's also the case in reverse.

    You are right about the fact that it is partly to reduce wheelspin, but reducing the power output in 1st gear also protects the clutch/flywheel because when you launch the vehicle it stresses a lot the clutch and the flywheel.
    Actually, in the 2000's manufacturers started to implement dual-mass flywheel on some diesel engines in order to increase smoothness, and a lot of these dual-mass flywheel had to be replaced before 100,000 km. It was a common issue for a lot of manufacturers: Peugeot, VW, Honda, Renault, Mitsubishi... And it is amplified by hard launches in 1st gear.
     
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  3. ARES IV

    ARES IV
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    Limiting power output in 1st gear is common in modern cars... especially in those with a lot of low end torque. Drivetrain stress is highest there because

    - Resistance is highest when going from stationary to moving - the difficulty in turning the wheel will never be higher in flat terrain.

    - Air resistance plays almost no role, allowing for very high acceleration values and as a result a particular fast rise in both torque and RPM.

    - Torque multiplication of the transmission is highest, creating enormous forces many times the engines rated torque in the aft part of the drivetrain:


    1. Example: No power limit in 1st gear, engine and wheel torque @ 4000 RPM:

    1ST gear
    Engine Torque: 179 Nm
    Wheel Torque: 2062 Nm = 11,5 times the force that the aft part of the drivetrain has to withstand
    Engine Power: 100,39 HP
    Wheel Power: 74,07 PS = 26,22 % drivetrain loss




    2ND gear
    Engine Torque: 179 Nm
    Wheel Torque: 1299 Nm = 7,3 times as much
    Engine Power: 100,49 HP
    Wheel Power: 87,44 HP = 12,99 % drivetrain loss




    3RD gear
    Engine Torque: 178 Nm
    Wheel Torque: 881 Nm = 4,9 times as much
    Engine Power: 100,59 HP
    Wheel Power: 92,55 HP = 7,99 % drivetrain loss




    4TH gear
    Engine Torque: 179 Nm
    Wheel Torque: 684 Nm = 3,8 times as much
    Engine Power: 100,38 HP
    Wheel Power: 94,22 HP = 6,14 % drivetrain loss




    5TH gear
    Engine Torque: 179 Nm
    Wheel Torque: 547 Nm = 3,1 times as much
    Engine Power: 100,48 HP
    Wheel Power: 94,29 HP = 6,16 % drivetrain loss




    6TH gear
    Engine Torque: 179 Nm
    Wheel Torque: 448 Nm = 2,5 times as much
    Engine Power: 100,39 HP
    Wheel Power: 94,29 HP = 7,36 % drivetrain loss





    As you can see:

    • Engine torque and engine power are always the same
    • The transmission multiplies the torque but not the power output
    • Drivetrain losses are highest in 1st gear, indicating significant internal resistance



    Now lets make the same comparsion with a power limited 1st gear in the 2.0 I4 Diesel:

    1ST gear --> Boost pressure limited to 0.7 bar
    Engine Torque: 294 Nm
    Engine Torque without boost limit: 402Nm
    Wheel Torque: 3118 Nm = 10,6 times
    Wheel Torque without Boost Limit: 4263 Nm
    Engine Power: 123,79 HP
    Wheel Power: 90,12 HP = 27,20 % drivetrain loss




    2ND gear --> Full boost pressure
    Engine Torque: 402 Nm
    Wheel Torque: 2699 Nm = 6,7 times as much
    Engine Power: 169,70 HP
    Wheel Power: 114,32 HP = 32,63 % drivetrain loss



    3RD gear
    Engine Torque: 402 Nm
    Wheel Torque: 2371 Nm = 5,9 times as much
    Engine Power: 169,59 HP
    Wheel Power: 145,02 HP = 14,49 % drivetrain loss



    4TH gear
    Engine Torque: 402 Nm
    Wheel Torque: 1707 Nm = 4,2 times as much
    Engine Power: 169,60 HP
    Wheel Power: 149,25 HP = 12,00 % drivetrain loss




    5TH gear
    Engine Torque: 402 Nm
    Wheel Torque: 1209 Nm = 3,0 times as much
    Engine Power: 169,48 HP
    Wheel Power: 151,46 HP = 10,63 % drivetrain loss




    6TH gear
    Engine Torque: 402 Nm
    Wheel Torque: 827 Nm = 2,1 times as much
    Engine Power: 169,34 HP
    Wheel Power: 150,50 HP = 11,13 % drivetrain loss




    7TH gear
    Engine Torque: 402 Nm
    Wheel Torque: 617 Nm = 1,5 times as much
    Engine Power: 169,47 HP
    Wheel Power: 147,82 HP = 12,78 % drivetrain loss


    • Even with twice the boost allowed in 2ND gear, the gear ratio put its output torque firmly below the boost limited 1ST. Maximum wheel torque is 3118 Nm compared to unlimited 4263 Nm in 1ST gear... allowing cheaper/longer lasting drivetrain components. Maximum Output Torque of 2ND gear is 2699 Nm.
    • So yes.. the risk of breaking your aft drivetrain parts is highest in 1st gear and as such it makes sense to limit power output there, especially as the cost in acceleration potential is probably very minor and the Tograc certainly wasnt meant for "no mercy to the material" driving.



    To be fair, while those transmission are the same in the game, changes are that in real life they would use a more durable one if necessary. Stress on the input side of the transmission is indeed always the same for a given engine output but the output side is a different story.


    Yes, I am from Germany.

    Informative :)
     
    #1383 ARES IV, Jan 9, 2021
    Last edited: Jan 9, 2021
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  4. SKB

    SKB
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    *Also rates Informative*
     
  5. NGAP NSO Shotgun Chuck

    NGAP NSO Shotgun Chuck
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    Honestly, I would place the FCV (both models) among my favorite cars to look at, but least favorite to drive. Most Vivaces, and *every* Tograc including the sports versioin, have utterly insipid handling that feels adequate at a 5/10ths jog but becomes painful beyond that. Massive understeer requiring large steering inputs for small changes of direction, but once they "grab" and turn in, they really turn in.
     
  6. CaptainZoll

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    try turning the esc off and putting in a tighter rear sway bar.
     
  7. NGAP NSO Shotgun Chuck

    NGAP NSO Shotgun Chuck
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    I always turn the sissy switch off first thing when I spawn one of these. Haven't tried the sway bar though. I was commenting on the factory setup.

    Speaking of which, is it accurate for the base model to have brake based torque vectoring? I could swear that it does.
     
  8. CaptainZoll

    CaptainZoll
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    i guess it makes sense they would just put the same ECU and brake control system in every car...
     
  9. default0.0player

    default0.0player
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    That's why I favor classic cars because classic drivetrains are indestructible unless crashed. "Common" modern car manufactures reduce drivetrain durability and engine power, making their cars weak.
    In less modern-ish vehicles, people can drive full boost in 1st in a regular basis without worrying about their driveshafts, because drivetrain strength should always be higher than tire grip.

    The problem with this specific vehicle (FCV) is the ridiculously high transmission friction. This also leads to poor fuel efficiency.
    When coasting at 4000RPM, the transmission power waste is 40% of total waste (60% is engine braking)
    BeamNGdrive-0212011103-RELEASE-x641_11_202110_46_31AM.png
    Flywheel Power: -32.32PS
    Wheel Power: -54.39PS

    Also when coasting at below 8km/h (clutch disengage) the wheel torque is a whooping -226Nm
    BeamNGdrive-0212011103-RELEASE-x641_11_202110_44_04AM.png
    A part-time AWD (and coasting is always FWD) with open diff has that amount of friction.

    In comparison, ETK856 TTSport+ when coasting at 4000RPM (8AT)
    BeamNGdrive-0212011103-RELEASE-x641_11_202110_49_32AM.png
    Flywheel Power: -38.81PS
    Wheel Power: -48.24PS

    But if you swap to an 8DCT then
    BeamNGdrive-0212011103-RELEASE-x641_11_202110_52_24AM.png
    Flywheel Power: -38.42PS
    Wheel Power: -59.08PS

    Also the Sunburst RS full-time AWD w/ mechanical LSD
    BeamNGdrive-0212011103-RELEASE-x641_11_202110_53_38AM.png
    Flywheel Power: -33.08PS
    Wheel Power: -45.37PS

    When coasting at below 8km/h (clutch disengage) the wheel torque is "only" -122Nm
    BeamNGdrive-0212011103-RELEASE-x641_11_202110_54_14AM.png

    Conclusion: In BeamNG, DCT is less efficient than AT, part-time AWD w/ open diff is NOT more efficient than full-time AWD w/ LSD.
    Today, most LCD screens with LED backlights used in TV, laptop and smartphone are flicker-free.
    However LED lightings in modern vehicles in recent years are not the case, even luxury brands such as Tesla and Cadillac have 100~120Hz flicker in their dashboard and taillights, recent BMW(headlights and DRLs) and Mercedes(DRLs) also have flicker, which makes driving in those traffic very uncomfortable. flicker → eye-strain → fatigue → higher accident rate
    --- Post updated ---
    Suspension tuning matters, the 310 Arsentic(FWD) has less understeer than 350(AWD)
    No, none of them(including the Arsenic) has brake based torque vectoring, because the eDiff logic is not working in a proactive manner, it will only brake the inner wheel after wait until the said wheel already slipping, hence the "grab". Try swapping one of the diff in the 410 Arsenic to mechanical LSD and note the handling improvement. If you want to do brake based torque vectoring you have to make the electronics to brake the inner wheel according to steering angle and lateral G, before the wheel even starts to slip.
     
    #1389 default0.0player, Jan 11, 2021
    Last edited: Jan 11, 2021
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  10. NGAP NSO Shotgun Chuck

    NGAP NSO Shotgun Chuck
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    Okay, I screwed up. Is it realistic for the base model to have an eDiff then?
     
  11. default0.0player

    default0.0player
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    Yes, but a bit different.
    BeamNG: The "old" ESC in BeamNG only compare diagonal wheelspeed, which is weird(cannot pass diagonal roller test). The "modern" Driving&Safety Electronics(DSE) on the other hand, it's eDiff and ESC work differently, eDiff working with ESC-OFF.
    IRL: Nowadays ABS & ESC are mandatory(at least in Europe), vehicle ESC requires wheelspeed, steering angle and g-force sensors, and TCS uses the same sensors with ESC(and often handled by the same computer as well), another separate sensor or computer is not required. The TCS brakes the slipping wheel and reduce throttle with ESC on, when the driver hit ESC-OFF button, the TCS switched to brake-only, which is beneficial in getting unstuck. Therefore, base model vehicles are capable of doing brake-only traction control (the same as eDiff in BeamNG). In higher end model the vehicle controller is tuned in a manner that brake the inner wheel according to steering angle and lateral g in a proactive manner, doing brake based torque vectoring(or simply use active differentials to save the brakes).
     
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  12. BrunoTheMerlin

    BrunoTheMerlin
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    I have to admit, I own a Hyundai Venue 2021 6-speed manual and I find the base edition Tograc similar.
     
  13. CaptainZoll

    CaptainZoll
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    come on ferrettank, we know you want to...
    extremetograc.png
     
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  14. Jakux

    Jakux
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    Tograc ate too many croissants and turned into an offroad beast. Electric one.
     
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  15. Kasir

    Kasir
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    Actually kinda scary how much that fits.
     
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  16. ARES IV

    ARES IV
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    Yes please. :cool:

    You can - to an extent - already turn the electric version of the Vivace/Tograc into an offroader. It is primarly held back by:

    • Heavy battery reduces ground clearance
    • A fact amplified by no offroad suspension being available for electric vehicles.
    • Lack of adaptive suspension components (suited for the heavier weight of the battery)
    • Lack of electric offroad drive mode... you are limited to comfort or sport mode which are both meant for tarmac and not for offroad.
    • For example sport mode would actually harden an adaptive sway bar instead of softening it...... maybe it can get through but your spine will hate you.
    • This also probably reduces the vehicles ability to move though mud/water/other poor traction heavy terrain situations.
    • Maximum possible gear ratio is not ideal for a crawling
    • An issue made worse if you are limited to playing with a keyboard.
    • Electric twin motors traction control lack an offroad mode, loosing theoretical capability.

    I suggested a while ago that we get a proper electric offroad variant for the Vivace/Tograc:

    https://www.beamng.com/threads/vivace-tograc-qe-offroad-parts-drive-mode.70463/



    Using the rally suspension the electric Vivace is still a reasonable capably offroader..... as long as nothing to high is in the way and you dont get stuck. It feels good enough for most "reasonable" offroad trails.
     
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  17. FordKing

    FordKing
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    It looks like a torgac that fell from 200 feet
     
  18. default0.0player

    default0.0player
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    In the 0.21 update, the eDiff on the electric Vivace/Tograc are removed, in order to make them offroady, the eDiff need to be re-added.
     
  19. Diamondback

    Diamondback
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    They never had them, nothing was removed, as explained here:
     
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  20. default0.0player

    default0.0player
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    Sorry I misunderstood, "They never had them" that make a lot of sense. It's still possible to add them (at least in off-road mods) to improve handling.
     
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