In order to solve the problem using your approach to vehicle physics, I’ll have to do some more experimenting. I tried to do vehicle physics many times before, and never could do it using the approach that you tried. This doesn’t mean there isn’t a good way to use that method, it just means I don’t know how!
I’ll be looking into it, but meanwhile, I’ve taken your project and re-did the vehicle physics taking the route that I would recommend. Your should find everything other than the vehicle physics the same. Since I used a completely different method, I won’t take time to explain all of the differences. I’ll just let you see for yourself, and if you have any questions please ask!
I did change the controls a bit. I enabled gradual steering using the mouse. The front car wheels are tracked to the mouse’s left-right movement. I noticed that your first person camera was also tracked to the mouse, so I added a logic brick to the camera and steering components such that if you click the left mouse button, then the first-person-camera will be tracked to the mouse; otherwise, the mouse will control steering. If you would rather revert back to “a” and “d” I have all of the logic bricks necessary to do so, but they are deselected (so they aren’t currently working). Just select the steering components (found inside the front tires), deselect the tracking actuator, and select the two motion actuators. You’ll have to do this for both steering components.
There is one bug in the steering component tracking the steering target. If the vehicle flips, the bug will show itself (and will be quite obvious); however, I’ve worked with it, and I haven’t been able to flip the car, so it should be fine. Reverting back to “a” and “d” will fix this problem should it occur.
To adjust vehicle speed, adjust the torque value on the wheels.
To adjust spring tension, adjust the force being applied to the four suspension components found at each wheel and/or the upward force being applied to the box surrounding the vehicle.
To adjust turning radius of front wheels, adjust the min/max value of the mouse.look actuator on the “steering target mover” (the smaller cube in front the front wheels).
Everything object should be named, so hopefully you wont have any problems finding anything.
Here it is:
I’m sorry that I was not able to help with the original method, and hopefully I can find a way to make the original way work (I’m actually interested in finding the answer myself!)
I hope that this helps, and if you have any questions or anything else, just let me know!!