HDV FRONT WING, REAR WING, DIFFUSER sections help

JoshJ81

Using FBMW rfactor stock F1 mod

[FRONT WING] said:
FWDragParams=(0.0190, 0.00322, 0.000016) // Base drag and 1st and 2nd order with setting
FWLiftParams=(-0.240,-0.0119, 0.000027) // Base lift and 1st and 2nd order with setting
Click to expand...

[REAR WING] said:
RWDragParams=( 0.045, 0.00547, 0.000023) // Base drag and 1st and 2nd order with setting
RWLiftParams=(-0.242,-0.01445, 0.000065) // Base lift and 1st and 2nd order with setting
Click to expand...

I understand perfectly what the 1st and 2nd number do for the wings. However, I've played with the 3rd number in each for Lift and Drag but can't see what it is doing. Can anyone help explain this? Is there a formula for figuring out what it should be?

[DIFFUSER] said:
DiffuserBase=(-1.045, 2.15, 85.0) // Base lift and 1st/2nd order with rear ride height
DiffuserFrontHeight=(1.450) // 1st order with front ride height
DiffuserRake=(-0.003, -20, 450.0) // Optimum rake (rear - front ride height), 1st order with current difference from opt, 2nd order
DiffuserLimits=(0.013, 0.105, 0.044) // Min ride height before stalling begins (0.0=disabled), max rear ride height for computations, max rake difference for computations
Click to expand...

For the diffuser, I understand the base number (or 1st number), but the 2nd and 3rd I don't quite see what they are for? I've seen some mods (CTDP F12006) use a negative 2nd number as apposed to FBMW using a positive 2nd number (shown in the quote). Is FBMW saying that the closer the diffuser is getting to the ground, the less downforce (negative lift number) is being created or rather a loss in downforce? And is CTDP's diffuser is creating more DF because of the negative 2nd number? Again what does the 3rd number do? It is very larger compared to the Front and Rear wing's 3rd number.

As well, can someone help explain what is exactly going on with the DiffuserFrontHeight=, DiffuserRake=, and DiffuserLimits= what each number value does?

I've looked some of this stuff up but most places just seem to repeat what the HDV says next to it, just not a lot of information on the exacts.

Thanks
JJ81
www.FiHSF1.net
 
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Thanks LesiU, but that only tells the formula how it works, very helpful...but.... What I mean, what is the purpose of those 3rd numbers? If the 1st is base ability of the wings, and 2nd is the added effect per click of wing changes, then what does the 3rd do? Same with the diffuser.

Thanks
JJ81
www.FiHSF1.net
 
For front/rear wing, 3rd is for non-linear characteristics. Thanks to that 3rd value, you can set your wing to provide slightly less (or more) downforce with each additional click.
With diffuser, i think it's the same (to have ability to define non-linear characteristic with ride height).

Here, you will find a pretty good description, of what's going on with aero (and of course not only that, because that website covers all rF physics files):
http://www.modding.frracers.ultramoron.com/PhysicsGlossary.shtml
 
Ah, good stuff. Just out of curiosity, why would we want to give slightly more? Is there something to do with trying to discourage full wing use everywhere, just asking? Thanks for the insights LesiU
 
Someone else will have to answer on that, because right now I only know some basics about aerodynamic devices :p
 
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It's not about encouraging/discouraging anything. It's about giving realistic response to wing setting.
For me it's pretty obvious that both lift and drag do not change linearily with wing setting.

Consider this:
-set wing at 0 degrees - you have low downforce
-set wing at 45 degrees - you have high downforce
-set wing at 90 degrees - you have little downforce again

If you draw a diagram for this function, you'll see what I mean: y = 2 + 11 * x - 6 * x^2

This gives:
for x = 0, y = 2
for x = 1, y = 7
for x = 2, y = 0

You need to be carefull with these values - if you use too high 2nd order multiplier, you can end up with wing that is actually lifting the car up when someone sets the wing too high :)
 
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Ah that makes perfect sense!

How would say that is works for the Diffuser?
 
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