Vehicle LongSlip and Gearbox


i’m playing around with the Advanced Vehicle Examples. My goal is a simple Trial/Offroad game. But it seems like the physics system is a bit strange, or i just don’t understand it.
There are a few strange things:

  1. Long Stiff Value (VehicleWheel): Any other value than 1000 makes the tires behave extremely strange. For example, if i change the value to 3000 (like in the Video-Tutorial) and open up the “showdebug vehicle” i can see that the tireLongSlip is jumping around. Lower values will make that the vehicle starts more directly but it has more slip on high-speed. Higher values will make the tires spin like crazy before the vehicle starts to move, but the slip on high-speed is lower. In my eyes this makes no sense.
    I want to archive that the vehicle starts moving when the tires starts moving, otherwise it will look very odd in an offroad-game. So my goal is that there is no slip on the tires if you start slowly. Even if i lower the torque to 30 the tires are slipping when the vehicle starts to move. Is this behavior a bug or is this correct, and i’m doing something wrong?

  2. The transmission is changing the gears to early. Specially from 4th to 5th Gear. Max RPM is 5700, UpRato is set to 0.9. So it should change gears at around 5130rpm. This works for 1st to 4th gear, but from 4th to 5th its changing almost immediately (at around 4000rpm). Why is it doing this? Any idea?

I have noticed the same behavior that you’ve observed with the Long Stiff Value. I’m bumping this post in the hopes that someone may have a solution.

the solution is to try and help with this, dont know if any of you have physics or coding experience?