Vehicle suspension, legacy physical properties mode, and my woes

I recently put together a suspension and steering rig for project I’m working on, and after a horrible amount of tuning and tweaking found that 90% of the bouncing issues I had on my car was because I was using the default solver and not the legacy solver.

I’m pretty sure I heard at some point or another the legacy solver was going away, so I figured I’d best report this because the default solver does not handle this well at all.

Attached is an RBXL of my car with the legacy solver turned on, hit play and observe it stabilizes pretty quickly, turn the solver to default and it’ll be a bouncy mess the entire time. Readjusting the force value in the default solver test to attempt to stabilize it works, but once you hit the point where it’ll sit fully extended it begins to bounce around again. All of the suspension rig has 0 elasticity and aside from the wheels 0 friction, so I’m clueless as to where the bouncing could be coming from.

A basic info graphic run down of how the suspension works (this same tear down layout is visible inside the attached rbxl).

bouncy physics.rbxl (37.5 KB)

In the event I’ve made a horrible mistake and the bouncing was caused by me please let me know, I’d love to get these cars working well.

And to anybody curious about the car and if they could use it go ahead and take it and do whatever with it, I don’t mind it being available to people.

It looks like your model is overconstrained.

Which makes sense, considering how your suspension works. There are some overlapping parts in there. Try following the debug instructions.

I guess that could be part of it but that shouldn’t really account for the big difference in the two physical property solver modes right? PGS turned on with legacy is totally different than PGS turn on with default. Turning PGS off totally destroys the rig regardless of what property solver mode I use.

Theres nothing that shouldn’t be colliding but I guess because of the weight of the car it’s creating over constrained areas by forcing the collision parts to merge a little (in particular where I have the suspension bars colliding with the limiter parts).