Alternative, DIY refresh Model X rear camber correction

I was thinking about this over coffee. Anybody who is considering spending $400 for the Macsboost kit could DIY this for next to nothing. I need somebody to confirm the relationship between the spacer thickness and the camber, but I don't have a refresh X. If anybody is in the Bay area I'd be down to shim and measure the camber and toe values so we can share the data freely.

Some notes:
- Another member has already confirmed the $400 shims are off the shelf 2.9mm (approx 1/8").
- Factory hardware appears to be M12

To do this at home you will need four M12 (metric, so the nominal diameter is 12mm) washers, approx thickness of 3mm; 1/8" is a close standard equivalent. A correctly sized washer will work in pinch.

If we can measure the factory arm's flange, I can draw a simple square part that others can customize for their desired thickness, if they want to hit a target alignment. There are plenty of shops that will mill these for you

Quick mock up with a non-standard thickness that I priced through Xometry. I quoted laser cut 6061 below but other materials are available for an additional cost. Grade 5 Titanium will double the price...to a whopping $11.

If you are happy with the alignment from the 1/8" thickness there is no reason to have a spacer machined.

Of course, the cost goes way down with volume and we can do cool things like anodize or powdercoat. There are also other manufacturing options available with volume.

If none of these options speak to you grab some 1/8" stock, a hacksaw, and a drill!

 

[ngng]

Thanks @ZuleMYP for confirming the measurements.

As promised, here is the model and print that anybody can fork to their liking. You'd only really need the model if you wanted to machine a non-standard thickness.

A few things to note about the part: I've increased the diameter of the M12 clearance hole and added an optional 1/8" radius around the part. The tolerances on this part are pretty much a football field

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If you are able to measure your camber and toe before and after, please contribute your information to this thread!

 

[DayTrippin]

I think their pricing was $200, that is what I paid. Not keeping up with current pricing. For the time I saved, at what I earn per hour, it saved me many times over what my time is worth. Glad to compensate and support someone for the time and effort they put in to develop something.

By the time I'd find someone to source and cut it locally, it just was better option for me to go with Macsboost and a huge savings over going with N2itive.

 

[ngng]

I think their pricing was $200, that is what I paid. Not keeping up with current pricing. For the time I saved, at what I earn per hour, it saved me many times over what my time is worth. Glad to compensate and support someone for the time and effort they put in to develop something.

By the time I'd find someone to source and cut it locally, it just was better option for me to go with Macsboost and a huge savings over going with N2itive.

Baller. I wish I made $200 for 15 minutes of work For all of the less fortunate, they can order from Online Laser Cutting and Waterjet Cutting Service and the parts will show up without having to lift a finger.

 

[TANGO SUKKA]

o hi jon huehuehue

 

[ngng]

o hi jon huehuehue

 

[ngng]

Have a friend who wants to try this on his car so I am going to order a run in 7075. If anybody is interested feel free to post. Probably $25 shipped to the CONUS.

 

[TANGO SUKKA]

remember that time we went to motogp at laguna and crashed at some random dudes house?

 

[MortonGarrett]

All of this is over my head. I’m curious what the benefit is of adjusting the camber of rear wheels. Makes the tires wear better?

 

[ngng]

All of this is over my head. I’m curious what the benefit is of adjusting the camber of rear wheels. Makes the tires wear better?

Basically, yeah

 

[DayTrippin]

There is too much negative camber. My first set of tires were out at 5K miles. It’s only an issue if you have 21 inch wheels.

 

[ngng]

There is too much negative camber. My first set of tires were out at 5K miles. It’s only an issue if you have 21 inch wheels.

That's 100% incorrect. This affect ALL Xs regardless of wheel size.

 

[TANGO SUKKA]

That's 100% incorrect. This affect ALL Xs regardless of wheel size.

why doesn't tesla fix this if it's such a simple and cheap fix?

 

[DayTrippin]

The car will show better numbers for road tests with the extra negative camber. It will translate into better turning capability on the track. The downside is accelerated tire wear.

 

[ngng]

why doesn't tesla fix this if it's such a simple and cheap fix?

They have no reason to fix it or the just don't care. I could understand aggressive camber since it does actually keep dumb people from killing themselves, but the crazy toe doesn't make sense. BMW has lik-1.5 for the rear on the X5. That being said, my X has -2.3 degrees of camber in the rear...that's more than I had in one of my Spec Miatas

 

[ShawnA]

Hi,

I installed the MacBoost spacers on my X.
I would recommend anyone trying to do this to use a 6 point socket.
The Tesla bolts are weird with a slight taper on the hex.
With the torque required to fasten them the hex can strip...

Good luck,

Shawn

 

[geordi]

The reason they do not fix it is that they do not care.

Tire wear is not something that a manufacturer gives a crap about. Handling on the other hand, especially when you are designing and marketing a vehicle for people to go out and drive like morons doing autocross every weekend… If you take your car on a slalom, as you lean into the turns a tire that is normally situated with the inside edge lower than the outside edge will lean outward and the tire will have a wider contact patch giving you better handling around the turn. This is good for someone driving at the limits of grip. 99.9% of the rest of us will never see a benefit and will just get pissed when our new tires wear out before the next season has elapsed.

If you are one of the .01% of the population who have a reason to drive your car at the limits of grip, you already know what you want. There is no reason for a stock vehicle to be configured in this way. What the general public needs, are cars that have the wheels angled as straight as possible and flat to the road. That will give them good contact patches, good grip, and long life.

 

[strider]

If you are one of the .01% of the population who have a reason to drive your car at the limits of grip, you already know what you want. There is no reason for a stock vehicle to be configured in this way. What the general public needs, are cars that have the wheels angled as straight as possible and flat to the road. That will give them good contact patches, good grip, and long life.

This is not the reason. This is a trend in all vehicles, especially SUVs. Here is a 2005 Honda Element. Look at the rear wheels. You can visually see the negative rear camber:

Honda did not do this so they could set hot laps at the 'Ring. They did it because people suck at driving. If you get into a corner too hot, poorly trained drivers will get scared and take their foot off the accelerator. This transfers weight to the front of the car which causes the rear to lose traction and the car will spin. This is called "lift throttle oversteer." So manufacturers add extra negative camber to combat this. They add even more in "performance" cars because it is even easier to get going faster than you want.

Now, the shorter the sidewall, the greater the effect on tire life. So that Element above won't notice the loss of tire life as much as a "performance" care with short sidewalls. I got 20k out of my rear tires w/ 20" wheels and factory geometry. But I am telling you that this trend is not for high performance reasons.

On top of that, for S/X, the factory geometry was set for medium suspension height. The camber was aggressive but not extreme. Then half shafts started breaking so Tesla made Low the default suspension height. That pushed the camber from aggressive to extreme.

 

[btec116]

Please compensate for the bolt thread length if you're doing this! I don't know what the thread engagement is on those but Tesla runs pretty tight on some (especially when they're not expecting these types of mods).
Same goes for standard wheelstuds often being too short on some aftermarket wheels, off-topic i know, but it helps illustrsate the point.
Thread engagement (the amount of thread actually under stress when tightened) will be a function of bolt diameter, grade and torque, if you take away thread, you're provoking torque-loss, thread stripping, and bolt failure. Just please do your homework.

 

[ngng]

Please compensate for the bolt thread length if you're doing this! I don't know what the thread engagement is on those but Tesla runs pretty tight on some (especially when they're not expecting these types of mods).
Same goes for standard wheelstuds often being too short on some aftermarket wheels, off-topic i know, but it helps illustrsate the point.
Thread engagement (the amount of thread actually under stress when tightened) will be a function of bolt diameter, grade and torque, if you take away thread, you're provoking torque-loss, thread stripping, and bolt failure. Just please do your homework.

No need to with the above shim thickness. Anything more will require new hardware.