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Tyres Heat.

Started by Mace-x, March 03, 2016, 02:38:29 AM

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Mace-x

Title says it all, on supermoto, the tyres build heat quite fast and stop getting traction untill it´s almost impossible to race.  :)

PeterV

March 06, 2016, 03:16:01 PM #1 Last Edit: March 06, 2016, 03:34:00 PM by PeterV
Video is coming, you defintly loose grip with higher temps on tyres but the values dont seem odd in garage.
Oher thing we noticed was that the lean angle will decline with each lap as well it seems.

It feels like its the wrong way around, grip wise.

http://www.youtube.com/v/BMIzxdPRQGE

Stout Johnson

March 06, 2016, 04:07:21 PM #2 Last Edit: March 06, 2016, 04:20:51 PM by Stout Johnson
Yes, definitely some issue there. Its not that noticeable on Holjes, but on all-tarmac track it is definitely strange and annoying. PeterV and myself just decided to have some fun on the track 'LaConca' (probably a kart track). Getting out of the pits, it felt great. We could get good lean angles and could really 'rock it'. But pretty soon (after 1-2 laps) it became noticeable, that the virtual rider reduced the maximum lean from lap to lap. Also the margin for error on slides became really small, so we fell a lot. After checking tyre temps in pits, they seemed quite normal though (in 30s). So back out with a fresh set of tyres, and the lean was realisitic again, also slides were much more realistic.

So there deninitely is an issue concerning the grip level with the Supermoto on tarmac. Tyres are ok out of the pits, but get considerably worse with each lap - reducing possible lean angles and sliding. It does not seem related to being overly aggressive with the tyres. I did some 'easy' laps where I did not brake very hard and would not slide ... still after 2 laps the lean angles were considerably smaller, getting worse each lap. Tyre temps being in the 30s ... so not sure what is happening there.

On a related note: In all your sims (GPB, WRS, and now MXB with the Supermoto) tyre simulation seems to be a bit odd. Some examples:

  • on wet track, tyre temps always seemed odd (in general too high)
  • on wet track, riding with slicks even on e.g. 50% dried up track is near impossible, like riding on ice
  • when sliding with the rear (power slide), the tyre always seems to be slippery for a second or two; even after throttle is released completely and tyre regained grip, applying even moderate throttle again shortly after, results in easy rear washouts.

For me it seems as if the tyre surface cooling off after having been spun (throttle) or slid (brakes) is not simulated correctly? The tyre surface can get very hot when being spun (resulting in the compound being rubbered off on the tarmac or even getting partially gaseous), but it also cools off on the surface very fast if the excessive friction is not applied anymore, resulting in the tyre getting grip again (that's why highsiders happen). For me it seems, as if the tyre cool-off is being simulated as if the tyre was still in contact with the tarmac all the time (which only happens in the rare case of locking the tyre completely on completely shut brakes); normally (esp. during and after power slides) the tyre is spinning, which results in the tyre surface cooling off as it is being exposed to air while spinning. 

So the question is how sophisticated is the tyre temps simulation... for me it seems as if it is being simulated without the cool off period while spinning in air and not being exposed to the tarmac. Also, do you consider that only the area of and around the contact patch area does build up heat very rapidly while being spun? The other areas will also get some heat off of that indirectly, but delayed and less the heat that is being absorbed in the mean time by cooling off in air. My guess would be, that if you sort that tyre temps simulation, you will get rid of many problems. I bet we could see much more realistic power slides due to the tyres not getting "icy" within split seconds, we could see much more realistic tyre usage in rainy/wet conditions, and we finally could see realistic high-siders if we have really sophisticated tyre temps simulation.