# My Car is bouncing and prone to crash

My problem is that the car I got is bouncing when I drive it, even on flat ground with box-collisionbounds. And its ruin the expirence to play my game.
The car is prone to bounce even more and roll over even more then turn left and right.
The feeling is much like drive with cubes as wheels, or something like that. Ofcourse they has cylinder-collisionbounds.
I got suspensions, and steering-hinges, and a car-body.

I followed a youtubetutorial to build a vehicle-game.
THIS ONE: https://www.youtube.com/watch?v=D8JmmwkUwfI&t=653s
I have tweaked the settings somewhat diffrent than what the tutorial shows, but its based of this tutorial.
I only used logicbricks, no pythonscripting, added breaking impulse treathold for fun.

I use UPBGE 0.30.0.
I included my .blend-project, without texture, so feel free to play with it, and if u know how to fix my issues I would be a very happy man.
0
Trackrace.blend (1.3 MB)

I don’t know, as i said i’m not using upbge 0.3.0.
It can be the physics similar to bunny hopping over physics lines on the ground plane. It can also be that the wheel get pushed into the plane and physics forces it out, pushing the wheel up.

I think its that, dont bounce in a big plane without grids inside, going straight.

You will have strange physics effects if you don’t apply the scaling to your objects. Also, the physical part of your track should be made out of invisible primitive objects (preferably box collision). Using triangle mesh collision bounds will give you more strange physics issues(more bouncing and flipping).

For example, with your file as it is now, you bounce around on the flat ground beneath the track even going straight. That’s because it is triangle mesh collision and not scaled properly. Switch on box collision bounds and apply the scale of that flat ground and watch how smoothly you can drive across it.

Another thought, you need smoother transistions on your track. There are sharp angle changes on it and hitting any of those at even moderate speed will cause a big bounce.

Hope that helps.

Thx, I applied boxcollisions om much stuff, also scales. Worked almost fine. Its less bouncy now.
The bouncyness is still a issue then I turning in medium/high spreds.

Try tuning your suspension to be softer, with more dampening, ad more travel. it might help (basic tuning lol) if you have dynamic suspension (where the 3d model bends to follow the suspension) then this might be more difficult, but you could have more travel by simply raising the point at which the suspenension is “mounted”