True coilover rear possible on Model 3?

[Gauss Guzzler]

Some sort of articulating rear weight jacks should be installed to reduce spring bow and possibly bind.

A true coilover rear will also eliminate the need for an ultra high rate spring that is too short and becomes unloaded at droop.

Just so you know, moving the spring outboard doesn't change the droop behavior. Springs are generally linear (F=kx) so the droop is determined entirely by the weight of the car vs the effective spring rate *at the wheel* and has nothing to do with the location of the spring. A softer outboard spring will have exactly the same droop as an equivalent stiffer inboard spring, even in the extreme case of a torsion rod which is all the way inboard. That's why they make progressive or helper springs.

And the rear spring only moves up and down by about an inch or so - you'd have to have a pretty crazy spring on there to be at risk of binding.

Aftermarket springs tend to be small diameter to save weight increase profits. If you're really concerned with bowing and binding try to find a larger diameter spring which will have much more clearance between coils.

 

[Motion122]

Just so you know, moving the spring outboard doesn't change the droop behavior. Springs are generally linear (F=kx) so the droop is determined entirely by the weight of the car vs the effective spring rate *at the wheel* and has nothing to do with the location of the spring. A softer outboard spring will have exactly the same droop as an equivalent stiffer inboard spring, even in the extreme case of a torsion rod which is all the way inboard. That's why they make progressive or helper springs.

And the rear spring only moves up and down by about an inch or so - you'd have to have a pretty crazy spring on there to be at risk of binding.

Aftermarket springs tend to be small diameter to save weight increase profits. If you're really concerned with bowing and binding try to find a larger diameter spring which will have much more clearance between coils.

The problem with high rate springs is that they are typically very short in length so they will become unloaded at part of full droop thus the need for a helper to keep them in tension. Moving the spring to a true coilover setup will eliminate the need for a custom or main and helper spring setup.

 

[Gauss Guzzler]

That's what I'm trying to tell you is an incorrect understanding. Just as an inboard spring needs to be stiffer than an outboard equivalent it also doesn't need to have as much travel - for exactly the same reason - the control arm leverage. It's a perfect exchange so the spring location is entirely irrelevant from this standpoint.