Rfactor 2 drs rear flap settings .hdv

Discussion in 'General Discussion' started by steveluppino, Jul 8, 2016.

  1. steveluppino

    steveluppino Registered

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    Hi,

    Im looking in posts for settings to adjust the rear flap settings in the .HDV file, but not having much luck.

    Can anyone drop in a few hints please on what each of the values does?

    Thanks.
     
  2. peterchen

    peterchen Registered

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    From an old, rF1-times physics glossary page:

    Front Wing details. Optional part in rFactor, cars with front wings will require these details. These can still be used even if the car does not have a front wing.

    FWRange= This is the adjustability of the front wing or air dam. Again 1st value is minimum setting. 2nd is Each step (Leave both these at 1, unless the wing is adjustable in degrees and it's adjustability differs from these values). The third value is how many settings you can have or how precisely you can adjust the car. Depending on the car a value of between 1 & 10 can be accurate. Only Formula One's have more adjustability (40 with stock rF physics), they are however, almost beyond this world in terms of technology. 1 for a road car, about 1-3 for most touring cars, about 10-20 for Cart. These settings must be accounted for in the Drag/Lift.

    FWSetting= What the front wing is set to initially. Usually this should just be set a little over half of the medium setting. You should always attempt to make default setting values a decent setup for most tracks, an average if you will.

    FWMaxHeight= From this height onward the front wing will not lose more downforce from an increase in ride height. With a high value the car can flip when the car leaves the car jumps, value should be around 0.2 for race cars.

    FWDragParams= This is the most complicated part. First value is initial (and hence minimal) drag at the base setting. The second value is drag increase per wing setting. Third value changes the the drop off in efficiency as wing is increased.
    The formula for calculating drag in real terms;
    Initial Drag + Drag Increase * (Wing Setting) + Efficiency drop off * (Wing Setting) ^ 2
    In other words. 1stValue + 2ndValue*(Setting) + 3rdValue*(Setting)^2
    Wing setting is the same as setting found in the SVM file. Meaning that the minimum is 0, not 1. A value of 1 in the menu is actually 0 in terms of setting.
    Here is an example.
    If Front Wing is set to 3 in the Menu, and FWDragParams=(0.06, 0.01, 0.00003)
    Then to get downforce produced we plug the numbers in the formula 0.06+.01*2+0.00003*2^2, the total drag at setting 2 (or 3 in the menu) is 0.08012.

    In a non-open wheeler vehicle it can be acceptable to have negative front wing drag at the base setting, so long as this is factored in the BodyDragBase= variable. Doing this will mean as you damage and lose your front bumper, you actually lose top speed (because it was producing negative drag). If you lose your front bumper/air dam/spoiler, air flow becomes rough and flows over the newly exposed wheels, creating extra drag. Obviously, in a race car you are likely to lose less speed, because the standard front bar is producing downforce and has more drag, a normal road car front bar is generally designed for minimal drag.

    FWLiftParams= First value is base lift, ie. lift at minimum wing setting. Note that negative lift is downforce. Second value is the lift increase per wing setting. These parameters are essentially the same as FWDragParams= but these variables apply to lift instead.

    FWLiftHeight= Higher values make it more sensitive to increases in ride height. Touring cars are not very sensitive to this and a value of about 0.3 is expected. This is because the front wing can only produce so much ground effects. F1 and Indy/Cart vehicles are very sensitive to this, a value of about 1 is appropriate as they have specially design the wings to produce ground effects. A DTM should probably be around 0.5. Reduction is easy to calculate. Take your base lift, add fwliftheight multiplied by front wing ground clearance (measured in meters). Lift+(LiftHeight*Ground Clearance). Say lift is -0.2, lift height is 0.3 and current ground clearance is 0.1m. Then -0.2+(0.3*0.1)=-0.17, at 20cm the lift is -0.14. In other words, this follows a linear progression. This is not accurate but it is probably not worth the CPU use of adding extra 2nd order variables, as the diffuser can be used to complement this.

    FWLiftSideways= Drop-off in downforce when wind direction is at 45 degrees to the wing. 0.5 would halve the downforce/lift @ 45 degrees. 1 will mean the wing no longer produces and downforce/lift at 45 degrees of slide. If you use peakyaw this value will become overwritten?
    Values close to 0.5 are considered to be accurate. When a wing is angled to it's heading direction, it's angle at 45 degrees, and assuming it's flat in it's X axis,

    FWPeakYaw= First value is the angle in degrees, at which maximum downforce occurs. The second value is used to multiply downforce at this point. Generally, without end plates, optimum downforce can only occur at an angle of 0 degrees to the air flow. Wing endplates are generally not present on the front wing of vehicles, with the exception of winged formula vehicles. End plates can increase downforce with yaw because they allow extra air flow to cover the downforce producing plane of the wing. This diagram (Not here yet) demonstrates how end plates increase downforce with yaw, the effective increase is not much, but when you consider vehicles do slide through corners a little bit, they can make a big difference. Insteady of losing downforce as the car drives through a corner (as would happen without endplates) downforce is actually slightly increased. Accurate values for open wheelers are around (2, 1.02). Open wheelers also produce ground effects using their front wings, yaw reduces the benefits of this by supplying more air under the diffuser and thus making it work less efficiently.

    FWLeft= Aero forces generated by moving left. The first value is the X axis resistance. Meaning that this should always be negative for left movements. Second value is Z axis resistance (vertical), 3rd value is Y axis resistance, forward or backwards.

    FWRight=(0,0,0) Aero forces from moving right

    FWUp=( 0,0,0) Aero forces from moving up

    FWDown=(0,0,0) Aero forces from moving down

    FWAft=( 0,0,0) Aero forces from moving rearwards

    FWFore=(0,0,0) Aero forces generated from moving forwards, this is recomputed from settings. Left over from SCGT?????, it's basically it's an old value and that does nothing (unless you delete the FWRange=, FWDragParams= & FWLiftParams=).??????

    FWRot=( 0,0,0) Aero torque from rotating

    FWCenter= Centre of forces acting on the wing in reference to the centre of front wheels at the reference plane.

    BodyDragBase= I don't know the exact method used to calculate this value in the game but you must include frontal area with drag coefficient. (Someone??) This will reduce or increase the cars top speed, low values will take longer to acheive absolute top speed. It will also increase acceleration, but obviously has a greater effect at higher speeds. Every time a car doubles it's velocity or speed, the drag will increase by four times. Open wheelers have a poor Co-efficiency of Drag however, they usually have a small frontal area which can almost compensate. A modern road car despite having a greater frontal area will probably be more aerodynamic than an F1.

    BodyDragHeightAvg= Drag increase or reduction as ride height is increased. Should be low value and possibly even negative for most road cars because this allows clean air to flow under the car. If the car has a flat full length under tray and purely race style, this value will probably be positive and greater than 0.1+. This is as a result of exposing suspension parts and tires.

    BodyDragHeightDiff= Increase in Drag when the car has different front to rear ride heights. Most cars have quite a high value, most race cars should be higher than 0.5, aerodynamically precise automobiles such as a Formula type car maybe be even greater than this. Anything wedge shape, like an old CanAm will be more sensitive to this.

    BodyMaxHeight= Max height game calculates drag/lift losses/gains from ride height. Remember that too high can cause unrealistic flipping. The diffuser should never produce lift when travelling forwards. See Diffuser, try to ensure diffuser never reaches less than about 5% of it's base downforce by altering BodyMaxHeight=.

    BodyLeft=(-0.7, 0.03, 0) Drag resistance when car is moving leftward. Notice the air resistance is in the opposite direction. All cars will have lift as an effect of moving sideward, with the possible exception of a sprint car, which when moving left? may produce some downward force. On the otherhand, a rightward movement of spring cars will result in high lift. On a normal car, I would expect a second value of around 0.03.

    BodyRight=(0.7, 0.03, 0) Aero forces due to rightward movement.

    BodyUp=(0.0, -1.5, 0.0) Aero forces from moving up

    BodyDown=(0.0, 1.5, 0.0) Aero forces from moving down

    BodyAft=(0.0, 0.10, -0.7) Aero forces from moving rearwards, drag should increase when moving rearward in comparison to forward movement, though it probably shouldn't be too much worse, on the other hand, lift should be significantly higher than driving forward. I don't think there is an automobile that would produce downforce when moving rearward. Reasonable range for a street car, 0.08-0.3, with most having around 0.2 lift value.

    BodyFore=(0.0, -0.045, 0.200) Aero forces from moving forwards. The second value, which affects lift, is important. 3rd value drag is overwritten by BodyDragBase. The second value, lift, is an important variable to get correct. This affects the cars high speed stability and can affect lap times enormously. Let's take a look at the 2000 Volkswagen Beetle. According to Internet Auto Guide the beetle has a wheelbase of 2512mm. Mulsannes Corner has the lift at 742 lbs @ 124 mph with the front having 332 lbs of lift and the rear having a lift of 411 lbs. A value 742 lbs is equivalent to a value of 336.5kg. 124mph is roughly 200km/h. From these variables we can conclude that the lift value should be approximately 0.69 for a 2000 volkswagen beetle. Very, very few vehicles will produce more lift at speed than the beetle, so you could consider this to be an upper threshold. The wheelbase will tell us where the BodyCenter should be placed on the Y-axis (3rd value, front to back). If you do the math, 2512*(332/742)=1124mm in front of the rear axle. So BodyCenter value 3 should be -1.124. Read BodyCenter= for more details.


    Is this the kind of info you need? The example is for the Frontwing but it is the same for Rear.Some things will have changed in rF2.
     
  3. Lazza

    Lazza Registered

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    That's a lot of aero info, but not the flap :)

    Open up the files for the skip barber in devmode, that's the most complete reference we have at the moment, think most stuff is covered (some more recent options you might need to refer to buildnotes etc)

    //FlapDrag=(0.0,0.5) // base drag when activated, multiplier by deactivated drag to add in
    //FlapLift=(0.0,0.7) // base lift when activated, multiplier by deactivated lift to add in
    //FlapTimes=(0.1,0.12,0.1,0.13) // visual activation, physical activation, visual deactivation, physical deactivation
    //FlapRules=(0.5,0.03) // throttle threshold, brake threshold for automatic deactivation
     
  4. steveluppino

    steveluppino Registered

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    Great, thanks.
     
  5. peterchen

    peterchen Registered

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    Oh, lol! Got it wrong. Sorry :eek:
     
  6. davehenrie

    davehenrie Registered

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    Could the DRS be used to simulate the moveable wing on the Can Am Chaparrals? (kinda DRS in reverse?)
     
  7. rigodon

    rigodon Registered

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    Activated means "open"? So, when you open DRS you reduce drag and increase lift, right? Then, I don't understand the positive numbers "0.5" and "0.7" in the above example. If we take the numbers from Formula Masters 2012:

    FlapDrag=(0.011,0.63)
    FlapLift=(-0.08,0.63)

    I see also 2 positive numbers. I think I'm not understanding what means "activated" and "deactivated". Can you help me, ┬┐please?
     
  8. Lazza

    Lazza Registered

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    They are multipliers, as per the //comments. If you multiply by less than 1.0 you are reducing the drag and lift.
     
  9. davehenrie

    davehenrie Registered

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    My 'guess' would be the 2nd positive value is a vertical height were the drag or lift is applied.
     
  10. davehenrie

    davehenrie Registered

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    ok "I" was wrong. Based on Lazza's info, here is how those lines work.

    FlapDrag=(0.011,0.63)
    FlapLift=(-0.08,0.63)

    In the normal down position, the flap creates 0.011 of drag. When the DRS button is pushed, the .63 multiplier comes into play. The physical flap lays flat and the drag is reduced by roughly a third. So 0.011 x .63 gives us a new drag value of: 0.00693. 0.0693 is a much smaller value and thus the car experiences reduced drag while the DRS is active.
    Same procedure for the downforce.
    The flap in the example above produces -0.08 downforce. (note: this is not a real value but a piece of calculation which is combined with numerous other calculations to produce the over-all downforce total. )
    So while the car is being driven without the DRS active, that flap/wing/aero-bit is producing downforce. When the DRS button is pushed, the -0.08 get multiplied by the same 0.63 and we end up with a reduced amount of downforce. -0.08 x 0.63 = -0504 <downforce is negative lift so negative numbers represent downforce. Positive numbers would represent lift>.
    The real voodoo in all this is how the numbers 0.011 and -0.08 have been chosen and how we know that engaging the DRS results in a 1/3rd drop in both drag and downforce. Research, research research.
     
  11. Lazza

    Lazza Registered

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    Almost, but no.

    The wing produces drag and lift in accordance with its HDV values; the first Flap value is a static amount of drag/lift to apply when the flap is activated. So above, 0.11 drag is added when the flap is activated.

    But, at the same time, the already existing wing drag (which might be, say, 0.4, depending on its value) is multiplied by 0.63. So for my purely made-up example, that would be 0.4 * 0.63 = 0.252. Total drag of the activated flap would be 0.252 + 0.11 = 0.362.

    Same goes for lift. Note these values aren't switched to immediately, the FlapTimes define how quickly the aero change is reached during both activation and deactivation.
     
  12. rigodon

    rigodon Registered

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    Thanks a lot for your explanations :)
     
  13. davehenrie

    davehenrie Registered

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    I can now see, at least in these lines, my Dream Chaparral 2E could be achieved. The only drawback, since I don't have any experience using the DRS, would be if the reverse- DRS could be engaged by the driver when the car is approaching and going through corners.
     

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