Sorry, can anyone show a picture of where on the tie rod you mark the track and street toe settings?
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Track camber: arms vs coilovers
- Thread starter destructure00
- Start date
The FUCA's came in on Friday afternoon, we will have them sent out this week once we finish assembly.
Quick question for you all. After aligning to the specs above, I notice that when I hit a larger bump/dip that compresses the suspension enough to have the car body dip and bounce back up, rather than feeling like just an up/down motion I get a small hint of a yaw or butt-swinging side to side motion as well. Not enough to cause a problem from a handling standpoint, but just enough to feel slightly uncomfortable. What about the above specs causes this? Camber?
You're still running the factory springs & dampers, right?
What you're describing sounds very much like what I'm feeling when the suspension is loaded up in a bend. I've got no suspension mods yet. I haven't quite pinned down what's causing it as I've had so few dry laps in the car so far!
It could be related to bump steer as I seem to get plenty of that on the road, but I think there's more to it than that.
Stock suspension other than FUCAS and rear camber & toe arms. I never noticed it before I had the alignment done.
Straight line. I notice it when hitting dips on the freeway.
The handling issue I have is happening when cornering at higher speeds as well, like taking a freeway interchange flyover at 60+ mph. The car feels darty, like it turns in, then lets go, then turns in, lets go, etc. It's not very confidence inspiring, lol. I'm pretty sure I've seen the traction control lights come on briefly while this is happening too.
In light of this, I want to try my hand at DIY alignment again. The biggest issue for me last time was trying to figure out individual toe per side, as the toe plates just tell me total toe. I tried the string method previously, but as described before, the rear track width is slightly narrower than front, which means that I can't just set the front and rear strings the same distance from the wheel face.
I spent some time yesterday and today trying to get a perfect square around the car using the string method. What I found yesterday was that the rear is 17/64" narrower than the front each side, or 17/32" total narrower. I moved the car and restrung it this morning and got the same numbers, so I think this is going to set me up to be able to do this successfully.
I was able to zero the steering angle using Scan My Tesla, and checked toe on all 4 wheels both yesterday and today, and got consistent numbers within 1/32" between days. Seems like the shop I went to either wasn't super accurate, or maybe something has changed since then.
Left Front
.05 deg toe out (1/32")
-1.6 deg camber
Right Front
.13 deg toe in (3/32")
-1.7 deg camber
Left Rear
.13 deg toe in (3/32")
-2.0 deg camber
Right Rear
.13 deg toe in (3/32")
-2.0 deg camber
Based on these numbers, can you guys see anything that would cause the weird handling issues I'm talking about? Front toe concerns me a bit (although I am far from an expert interpreting these things), Tesla spec and my reading online seems like the front toe should be zero if not slightly toe out. Seems like rear toe is ok.
I'm thinking about putting the 8mm shims in up front (currently have 2+4 in there) to bring camber down closer to -1.0 deg, setting front toe to zero or very slightly toe-out, and setting rear camber to -1.5 deg or so, with very slight toe in. At this point I'm accepting that track day prep is going to be much more involved than swapping wheels and tires...I'll also be swapping pads/rotors and adding mud flaps to keep tire chunks off my doors and rocker panels, so making small alignment adjustments probably won't add a significant amount of time once I get the positions marked front and rear.
In light of this, I want to try my hand at DIY alignment again. The biggest issue for me last time was trying to figure out individual toe per side, as the toe plates just tell me total toe. I tried the string method previously, but as described before, the rear track width is slightly narrower than front, which means that I can't just set the front and rear strings the same distance from the wheel face.
I spent some time yesterday and today trying to get a perfect square around the car using the string method. What I found yesterday was that the rear is 17/64" narrower than the front each side, or 17/32" total narrower. I moved the car and restrung it this morning and got the same numbers, so I think this is going to set me up to be able to do this successfully.
I was able to zero the steering angle using Scan My Tesla, and checked toe on all 4 wheels both yesterday and today, and got consistent numbers within 1/32" between days. Seems like the shop I went to either wasn't super accurate, or maybe something has changed since then.
Left Front
.05 deg toe out (1/32")
-1.6 deg camber
Right Front
.13 deg toe in (3/32")
-1.7 deg camber
Left Rear
.13 deg toe in (3/32")
-2.0 deg camber
Right Rear
.13 deg toe in (3/32")
-2.0 deg camber
Based on these numbers, can you guys see anything that would cause the weird handling issues I'm talking about? Front toe concerns me a bit (although I am far from an expert interpreting these things), Tesla spec and my reading online seems like the front toe should be zero if not slightly toe out. Seems like rear toe is ok.
I'm thinking about putting the 8mm shims in up front (currently have 2+4 in there) to bring camber down closer to -1.0 deg, setting front toe to zero or very slightly toe-out, and setting rear camber to -1.5 deg or so, with very slight toe in. At this point I'm accepting that track day prep is going to be much more involved than swapping wheels and tires...I'll also be swapping pads/rotors and adding mud flaps to keep tire chunks off my doors and rocker panels, so making small alignment adjustments probably won't add a significant amount of time once I get the positions marked front and rear.
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Having some left toe out and right tow in on the front is just plain wrong. Personally, I think just a small amount of toe in or toe out is best, depending on your personal preference.
Why do you have -2 camber on the rear? Especially as you have less than -2 on the front? I'm now running -2.5 on the front and -1 on the rear. I'd like to go with more but the MPP FUCAs don't allow it.
To me, the handling issue sound like the car's getting on the bump rubbers, which it does very easily. In a compression the car squirms and it feels like the rear end is moving left and right on it's own. The only solution to this IMO is replace the factory suspension. I've done that now and that issue has gone.
Agree on the front toe issue....possible that it was due to the steering wheel not being quite centered when they did it...the guy eyeballed it where I'm using SMT to set it to zero degrees.
For the -2 rear, I was trying to set and forget the rear, have something that I could use on the track and on the street, and only swap shims and adjust toe on the front. Now I'm thinking I need a track and street setting for both front and rear instead.
I don't think this is a suspension bottoming out issue. I'm at stock height, and never had these issues until I started playing with camber and alignment. I'm pretty confident it's a result of the alignment settings, just not sure which one.
jgrgnt
Member
I used to experience this as well, on the stock suspension. It was a very unnerving sensation, and easy to reproduce on fast highway transition ramps, where one side of the car is loaded up. I did a sway bar (front and rear) upgrade first, and that seemed to reduce the sensation by about 50%. When I did coilovers (MPP Sports), it went away completely. Car feels extremely buttoned down and stable.
Clivew
Member
It doesn't work that way at the front. If the steering wheel wasn’t at the neutral position when aligned (which it probably wasn’t if they did it by eye), then if set at ‘0’ with SMT, it could quite easily show toe-out on one side and tow-in on the other. In reality, the toe will be the sum of both sides, and the steering will always find the central position and the toe will equalise when driven.
I realise now I read the post wrong. I didn't get that those settings were how he measured it after setting the wheel straight with SMT.
This is really all coming back to using an alignment specialist who knows what they're doing when setting the suspension up. I know the string method can be very accurate and is used in F1 etc. but you still need the space and a level surface to do it. It also helps to talk over changes with someone who has heaps of experience in that area.
It's not so much bottoming out as getting onto the bump rubbers with relatively little compression. The rubbers are progressive, but it means the overall effective spring rate rises rapidly once compressed and results in much less control over bumps and in long corners.
There's a corner on one track I go to a lot where the car is at near maximum compression on the exit and even though it's straight at that point, the rear would move about a lot. It happened elsewhere but was very obvious there. I can see how when @jgrgnt stiffened up the sway bars it would help in some corners, but aftermarket coilovers is the only way to eliminate it.
Clivew
Member
Ok, cool!
Yeah, it’s all well and good having top dollar laser alignment equipment, but you need someone who knows how to use it, knows the car, and has the detailed mind to get it spot on. Little things like rolling the car off, settling the suspension and then re-checking. I did the chassis set-up for a Pro Time Attack team for a season a few years ago, and always adjusted/checked alignment in the pit garage using strings and a simple camber gauge.
Yes, nothing wrong with the 'traditional' approach if you know what you're doing.
In terms of Teslas, I think one good litmus test of an alignment centre is to see if they put the weights in the car's footwells...
Clivew
Member
And needs must. When the driver has just thrown the car into the barrier in qualifying, the only option after fitting new wheels and suspension arms is to use strings to re-align. After filling the swear box up, obviously.
I need to come up with a way to allow the tires to turn freely then will be attempting a string alignment. Probably going to get some small plexiglas sheets or something and sandwich some grease between them, then roll a tire on top.
So, OEM the car behaved. I would check the suspension by jacking up the car safely one corner at a time and try to twist the tire in the toe direction and the camber direction. It is best if the steering wheel is held steady when checking the front. I drove a car that always kept its alignment but had a cracked control arm that exhibited behavior like you described. I found it using the above method.
Are you still on stock tires and wheels? If not and it is easy to return to, switch back when you are checking the suspension. Some treaded R compound tires used to behave like they had to give before they gave full grip with certain pressures. Although they didn’t have the problem in a straight line like you describe.
Are you checking toe with plates or strings? If with strings, describe how you are setting up the strings please.
Are you still on stock tires and wheels? If not and it is easy to return to, switch back when you are checking the suspension. Some treaded R compound tires used to behave like they had to give before they gave full grip with certain pressures. Although they didn’t have the problem in a straight line like you describe.
Are you checking toe with plates or strings? If with strings, describe how you are setting up the strings please.
I'm on stock wheels and tires, yes.
I realigned the rear this evening, set rear camber from 2 deg down to 1.3, and got 1/64" toe in each side, which should be about .05 deg total. Originally it was at 3/32" each side, which is about .26 deg total.
Didn't get a chance to test drive, will do it tomorrow and see if it feels any better. Will also measure rear again after driving to see if my measurements are consistent.
I'm checking with strings. I measured the rear width to be 17/64" narrower each side, so strings are parallel to the car measuring off the wheel face near the center, with the rear distance from face to string 17/64" further than the front.
