Hi,
I'm about to install rear camber shims. I figured I'd do at least some initial toe adjustment myself. I have done it before on my earlier P85+ using strings, but now I had bought a chinese laser to make it easier.
I figured I'd measure my current setup first, before installing the shims.
First I measured camber with water level, it's pretty easy. I have about -1.5 degrees per side, with car in Low.
Then the toe. Here's my top notch laser setup:
The laser is this one from aliexpress:
Then I measured the beam distance to the front wheel cap, and also to the rear wheel cap. Front right was 120mm, front left 115mm, rear 78mm+20mm=98mm.
Now there was an issue that I did not know how much more inside the front wheel is. It obviously is a bit. Tesla claims that track width is 1690mm both front and rear, but even then there is the issue that front wheels have offset of 45mm and rear only 40mm.. Track width is measured to the middle of the wheel, so offset difference of 5mm would mean that the front hubs would need to be 5mm OUTER than the rear, which doesn't make sense and must be incorrect. Edit: Turns out offset is 45mm rear and 40mm front, so with same track width front hub would be 5mm inwards which does make more sense.
This site lists 1662-1700mm for the front:
Still not very helpful that gives a hint that there is some "tolerance" in the front track..
I decided to add marks to front and back of car so I could accurately measure toe without relying on the front hub location.
The boxes at rear are positioned exactly between the laser lines, and then there's plywood plates at front where I marked the laser location with a pen.
Distance between laser beams at front = 212.5cm
Distance between laser beams at rear = 210.0cm
Distance from plywood to the box = 645cm
Then it's just math. angle = atan( ( 212.5-210) / 645 ) = 0.222 degrees of total toe out! Isn't rear supposed to be toe in? Doh.
Anyway, now that I know the actual toe, I can use that to calculate how much more inside the front hubs are. Wheelbase is 2960mm. 0.222 degrees at 2960mm distance is 11.5mm. My measurements were 120mm+115mm-98mm-98mm = 39mm, from which we deduct 11.5mm = 27.5mm. That would be 13.75mm per side. Round that to 14mm and we have 1690mm-28mm=1662mm which was the number mentioned in car.info link above..
Toe per side calculated from my original measurements:
Left 115mm: atan( ( 115 - 14 - 98) / 2960) = 0.058 degrees
Right 120mm: atan( ( 120 - 14 - 98) / 2960) = 0.155 degrees
Total now becomes 0.212 degrees, slight deviation from the original measured 0.222 but close enough and very easy to measure from the front hubs.
But still it's toe out, doh.
I'm about to install rear camber shims. I figured I'd do at least some initial toe adjustment myself. I have done it before on my earlier P85+ using strings, but now I had bought a chinese laser to make it easier.
I figured I'd measure my current setup first, before installing the shims.
First I measured camber with water level, it's pretty easy. I have about -1.5 degrees per side, with car in Low.
Then the toe. Here's my top notch laser setup:
The laser is this one from aliexpress:
Then I measured the beam distance to the front wheel cap, and also to the rear wheel cap. Front right was 120mm, front left 115mm, rear 78mm+20mm=98mm.
Now there was an issue that I did not know how much more inside the front wheel is. It obviously is a bit. Tesla claims that track width is 1690mm both front and rear, but even then there is the issue that front wheels have offset of 45mm and rear only 40mm.. Track width is measured to the middle of the wheel, so offset difference of 5mm would mean that the front hubs would need to be 5mm OUTER than the rear, which doesn't make sense and must be incorrect. Edit: Turns out offset is 45mm rear and 40mm front, so with same track width front hub would be 5mm inwards which does make more sense.
This site lists 1662-1700mm for the front:
Still not very helpful that gives a hint that there is some "tolerance" in the front track..
I decided to add marks to front and back of car so I could accurately measure toe without relying on the front hub location.
The boxes at rear are positioned exactly between the laser lines, and then there's plywood plates at front where I marked the laser location with a pen.
Distance between laser beams at front = 212.5cm
Distance between laser beams at rear = 210.0cm
Distance from plywood to the box = 645cm
Then it's just math. angle = atan( ( 212.5-210) / 645 ) = 0.222 degrees of total toe out! Isn't rear supposed to be toe in? Doh.
Anyway, now that I know the actual toe, I can use that to calculate how much more inside the front hubs are. Wheelbase is 2960mm. 0.222 degrees at 2960mm distance is 11.5mm. My measurements were 120mm+115mm-98mm-98mm = 39mm, from which we deduct 11.5mm = 27.5mm. That would be 13.75mm per side. Round that to 14mm and we have 1690mm-28mm=1662mm which was the number mentioned in car.info link above..
Toe per side calculated from my original measurements:
Left 115mm: atan( ( 115 - 14 - 98) / 2960) = 0.058 degrees
Right 120mm: atan( ( 120 - 14 - 98) / 2960) = 0.155 degrees
Total now becomes 0.212 degrees, slight deviation from the original measured 0.222 but close enough and very easy to measure from the front hubs.
But still it's toe out, doh.
Last edited: