Hey guys, I am wondering what are the primary factors in the physics that are responsible for the car sliding and heating the tires? I've looked in the TGM model and adjusted a few of the settings, however, it seems to me the behavior of the car and whether or not it is actually sliding seems to have the biggest impact on wear. With that in mind, I recently noticed that the 397 McLaren 650S has the tire temps quite considerably lower and less sliding in the corner when pushed. What tire and HDV parameters have the greatest impact on the sliding, temp rise, and tire wear?
From TGM: StaticBaseCoefficient=1.943 SlidingBaseCoefficient=1.36 Higher the grip less likely for you to slide the car, less heat to the tyres. (sliding value should be ~70% of the static) BaseDamperPerUnitArea Controls rolling resistance BulkMaterial=(273.15,1232,1.95e7,0.4725,1,1363,0.25) In the material definitions the last 2 values controls the Specific Heat and Thermal Conductivity. AbrasionVolumePerUnitEnergy // m^3/J volume of rubber sheared per Joule energy, max 32 values DegradationCurveParameters DegradationPerUnitHistory Depending how much you go over certain temp limit and how much time it is above this limit lowers X amount of tyre grip. DampingHeatEnergy=(1.0,0.4,0.8) // (Fraction of ring damping heat into sidewall (should probably be 1.0), fraction of bristle damping heat into carcass, fraction of bristle damping heat into tread) the 2nd and 3rd values should generally add up to 1.0 InternalGasHeatTransfer=(10,5,0.6) // (base, mult, power) - heat transfer coefficients to internal gas cavity = base+(mult*(vel^power)), where vel is linear velocity of tire ExternalGasHeatTransfer=(8,4,0.6) // (base, mult, power) - heat transfer coefficients to external air = base+(mult*(vel^power)), where vel is linear velocity of tire GroundConductance=(1000,0.003,0) // (base, mult, reserved) - thermal contact conductance coefficient to ground = base+(mult*pressure), where pressure is contact pressure and the reserved variable will be used at some later stage. WetConductance=(710,730,0,0) // Additional conductance due to (<dampness>, <wetness>,<and reserved for future usage 1>,<reserved 2>) TireRadiationEmissivity=0.936 // thermal radiation emissivity for external tire surface In the HDV there isn't any parameters for tyre heating unless you count the whole HDV as one.. http://imagespaceinc.com/downloads/rf2/modsresources/rF2_TGM_TyreTool_QuickStart_V3.pdf http://rfactor.net/web/wp-content/uploads/2011/05/TGM-Gen-V0.29-Brabham-BT44-Rear.ods
Thanks for the reply. I looked at some of those variables, but it seems to me the car wants to slide too much. For example, when driving the McLaren, it slides the tires but not as aggressively as the car I'm looking at. I wonder if inertia's are having an effect here because it's in slower corners where the tires really slide, they come up to about 110C or so then gradually go back down to around 80 or 90. The tires are basically sliding a lot and overheating. The McLaren they get up to 90 in the corners then drop to about 65C. So the car is either sliding too much and overheating the tires or the tires are the problem. What else should I look at in the HDV or Chassis ini to reduce the car wanting to push the tire sideways in the corner? Seems I have a lot of lateral force on the tire.
Also I'm noticing a lot of the 397 cars have more balanced tire heating so I'm wondering what has changed. I'm basing my tires off of the TGM examples released by ISI. Seems the 397 cars aren't as hard on tire heat.
Tire heating in corners is normal, it's the surface heat that is measured in rF2 (as opposite to rF1), and surface heat does increase a lot in corners for example with F1 cars: McLaren to me does heat less and wear less than some other ISI cars, but then again it's the same guys that used to work for ISI working with S397 on content now, so it's probably just that they have more accurate information now than a few years ago.
Yeah that could be. I need to evaluate the tires a bit further because I think the specific heat values are worth looking at. I could always reduce the wear rates such as the rubber shear values and activation temp and curve parameters.
I was looking yesterday night at some side views of the s397 McLaren and found the tires seem less stiff (more deflection), so it could be that what is happening is my tires are too rigid and so they are skating across the track.
