Physics Suspension travel. Basic position.

Andrey Korotkov · Nov 10, 2021

Hello everyone!
Help with advice, please.
I can not set the initial position of the rear suspension. The rebound travel should be 30mm. It turned out 21.xx and I just can't change it.
Initial data:
Total stroke: 75mm
Compression: 45mm
Rebound: 30mm.

The suspensions.ini contains:
...
ROD_LENGTH=0.040
...
BUMPSTOP_UP=0.031
BUMPSTOP_DN=0.054
PACKER_RANGE=0.086
...
I can't understand what needs to be changed in order to raise the car by 10mm)))
Any changes to the data above are ineffective.
Thanks!

Stereo · Nov 10, 2021

Those look like they should be able to perform, if they're doing absolutely nothing, there's a few things to try
1) colliders. not relevant here since you're limited on rebound rather than compression, but worth keeping in mind. if the collider bottoms out, rod length can't fix it. Also if it's bad enough nothing will be able to move the wheel until you get to very large values for rod length.
2) setup.ini. Any value controlled there will be clamped into a min/max range that suspension.ini cannot exceed. So if your rod length is limited to 0.0 to 0.03, changing it from 0.04 to 0.05 won't rise the car 1cm.
3) spring rate + bumpstop rate. If your spring rate is too low, you can be relying heavily on bumpstop rate and not see any movement from the rod length, because that value is only moving the spring.

Just in general while setting up bump_up and bump_down you probably want to set packer_range to a very large value; as in maybe 10 times larger than the others. The interactions between them means it's kinda the easiest one to hit. But again that shouldn't be limiting downward travel.