Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

[lolachampcar] Performance Upgrade Efforts

This site may earn commission on affiliate links.

lolachampcar

Well-Known Member
Nov 26, 2012
6,469
9,368
WPB Florida
I've been reading over some the stability control compliance documentation ( FMVSS 126 link below) and I'm getting a better feel for why Tesla may have made the decisions they did and why the P+ package took as long and costs as much as it did/does. The yaw stability test in particular goes a long way towards explaining why any manufacturer would use large amounts of negative camber at the expense of tire wear.

I'm speaking with some other MS owners offline with the goal of putting together the ability to do a minimum of bushings and damper/springs in addition to the camber links which are already done. The key is getting enough people on board to make doing development dampers a reality. I'm sure the project will extend to sway bars as well at some point but my past experience has taught me to get compliance where you want it before considering roll control.

I think Tesla may be limited on what they can and can not do for regulatory reasons thus my desire to work outside these restrictions.

[Mod Note] This thread was broken out from another thread in order to isolate discussions particular to lolachampcar's efforts.
 
Last edited by a moderator:
Put me in the 'I have contacts' category and I'm available to help. I may end up getting the factory retrofit, rather than pursue a more custom solution, but if so I'd still be available to put you in touch with some top notch suspension people in the Bellevue/Seattle area who would probably be interested in this project.
 
Lolachampcar: great idea. wanna make sure I understand what you are looking to do here:

develop a damper / spring (coilover) package for those wanting more performance ? issue I see is most here are on active suspension (main reason I went with std suspension), it will be trickier with software integration.

another lower cost option would have Bilstein revalve the dampers. They do it all the time, and cost minimally.

another solution is to develop camber kit like you have done, but commercialize it. This will add adjustability to suit everyone's driving style.
 
Lolachamp- I'm curious about the camber change. You first made an offset bushing to test the length of the control arm. Rather than installing longer control arms, is it reasonable to put such a bushing into service? I would imagine it would require some sort of set screw to keep it from rotating.
 
Lolachampcar: great idea. wanna make sure I understand what you are looking to do here:

develop a damper / spring (coilover) package for those wanting more performance ? issue I see is most here are on active suspension (main reason I went with std suspension), it will be trickier with software integration. No... I'm heading the direction you suggested below. I did not want to contact Bilstein without more than just my requirements. I was concerned it would take more than just a four damper solution purchase to get their attention. I was wrong. As you point out, the original equipment dampers are re-buildable. Bilstein will do it (six week backlog) or they will sell the bits to convert the dampers to field re-buildable (Schrader valve installation for charging) and shims to re-valve them yourself. The tech I talked to was VERY helpful. I'm pulling the Bilstein part numbers off my dampers today so we can get a baseline. The new shim stack can be our own or perhaps we can pull the part numbers off the P+ units and stick with what Tesla has done. I do have access to a shock dyno if we head down our own path. Doing baselines on 535 and M5 dampers will provide a good idea of the type and degree of required change. All my work has been with Ohliens TT44s on open wheel cars so I am looking for any reference points I can find. In addition to damping, I'm going to have a conversation with people on the air spring side of the equation as well. We may want to up the spring rate as well which will mean new bags. The ride height sensors should put the car right back to the correct ride height even with different spring rate bags (different static pressure for a given ride height).

another lower cost option would have Bilstein revalve the dampers. They do it all the time, and cost minimally.

another solution is to develop camber kit like you have done, but commercialize it. This will add adjustability to suit everyone's driving style.
The upper link docs are available to anyone that wants them. I've got a second water jet shop quoting the design as a few have asked me for links. I would love to work with people that have similar interests but have no desire to produce parts to sell to people. I'm retired, would love to be helpful but like being beholden to none :)

Bill

- - - Updated - - -

Lolachamp- I'm curious about the camber change. You first made an offset bushing to test the length of the control arm. Rather than installing longer control arms, is it reasonable to put such a bushing into service? I would imagine it would require some sort of set screw to keep it from rotating.

There are a couple of things going on here. First, I learned that with modern street car suspension the angular movement between the control arm and the upright or chassis is taken up by flexing of the rubber annulus of the rubber bushing. The outer sleeve of the bushing is a press fit in the arm. The inner sleeve is clamped in the upright or chassis. Given this, I could not use the offset bushing as it would be clamped in the upright or the chassis thus causing relative movement between the offset bushing and the control arm. That would be wrong in way too many ways :) You would have aluminum to aluminum relative movement with its associated wear and the camber would change as the offset bushing rotated in the link (thus changing the effective link length).

Oh, the second thing is that you need the bushing flex to actually get the bolt back in when putting the suspension back together again. The link is not perpendicular to the upright when the suspension is in full droop (torque link affect) which makes it a PITA to get the bolt back in. The offset bushing would have no flex thus it might not even be possible to get it back together. As was, I had to install the outside bolt first then use the link itself as a lever arm to get the inside bushing in. I can only imagine how much fun it will be doing this with less compliant performance bushings.
 
Oh, the second thing is that you need the bushing flex to actually get the bolt back in when putting the suspension back together again. The link is not perpendicular to the upright when the suspension is in full droop (torque link affect) which makes it a PITA to get the bolt back in. The offset bushing would have no flex thus it might not even be possible to get it back together. As was, I had to install the outside bolt first then use the link itself as a lever arm to get the inside bushing in. I can only imagine how much fun it will be doing this with less compliant performance bushings.[/QUOTE]

I have not seen a Model S suspension in person yet, but from a performance, adjustability and non-binding perspective, without the issues with compliance I would opt for a bushing setup like this: http://scandc.com/new/node/185, but with an adjustable arm, like these: http://scandc.com/new/node/102.

The big issue is the height sensor with such a setup of course. They will probably weigh a little more than stock too, but could equally well be made with aluminum tubing, I read a thread where an aircraft engineer created rear lower control arms with alu tubing and some kind of similar rod ends/johnny joints/spherical bearings.
 
I looked at the JohnyJoint. It was an attractive option but I suspect a custom configuration would be needed (either from currie or just build one) for a 1/2" though bolt and 1.6" OD (used on MS). These joints would be expensive in comparison to stock type MS or MS P+ bushings assuming we could locate the original manufacturer of the original equipment (OE) style bushings. I'm spending my time now finding a vendor for the OE type bushings. If I do not have any luck, perhaps these joints would be a way to go provided we were willing to make bespoke parts for each MS joint (at least two different sizes).