Traction control activating on interchange ramps and cloverleafs. Alignment or software?

[destructure00]

I've been seeing traction control kick in lately when taking freeway interchange ramps at speed (>60 mph), or taking cloverleaf type exits at >40mph. These are places where I never used to have any type of intervention, so something has changed.

First question....has anyone else seen more aggressive traction control intervention in scenarios like this after any of the software updates over the past couple of months?

The other possibility in my case is that I installed rear camber arms and front upper control arms back in March for additional camber at the track. I have had the rear at -2.0 degrees and front at -1.7 degrees for a few months. Recently changed the rear to -1.5 degrees and still seeing the same TC intervention. Toe has been checked and adjusted accordingly, currently sitting at 1/32" toe-in for the rear (about .05 degrees) and zero up front.

Only two things that have changed recently are software updates and alignment, so trying to figure out if others have seen increased TC aggressiveness, or if I need to keep playing with the camber on the street and set it closer to factory specs to prevent TC engagement in these scenarios where it's not necessary.

 

[MasterC17]

A few thoughts.

SMT does not necessarily show the steering angle at 0 when the steering wheel is dead straight. SMT on my car is off by about 2 degrees. Ensuring the steering wheel is dead center when performing an alignment and ensuring it stays that way is critical. That is why most alignment shops (should be anyway) using a level and a lock.

Changing the camber from stock to your current settings can affect toe drastically (a degree or more) and it may take two alignments to set it correctly. The alignment machine can't compensate for such a drastic change the first time around. It will usually give you an error and ask you to roll the car again after getting the toe close. But most people will just ignore it.

I guess the biggest question is - have your tires changed? E.g. are they different, or perhaps worn?

I don't think reducing the camber is going to help your problem, if anything it will likely exacerbate it.

To answer the question, I personally have not found traction control to be any more aggressive due to software updates.

 

[destructure00]

Good thoughts.

Tires: both of the rears are nearly new. The fronts are probably at half life. Running OE 235/35-20 PS4S. I need to go look again but I haven't noticed any uneven wear.

I've gone back to DIY for the alignment. Took the time to set up a perfect square using strings to set toe. Found the rear to be narrower by 17/32" overall. I've set this up and taken it down, gone for a drive, set up again, and got consistent numbers. So at this point I'm confident in my numbers, and I trust them more than the shop that I had do the initial alignment.

Here's the progression. I've noticed the TC issue with all settings below.

Shop laser-alignment
Their machine said 1/32" toe in each side rear. 1/32" toe in each side front. Rear camber -2.0, front camber -1.6 and -1.7 deg.

I measured this via strings and camber gauge, after driving a few thousand miles.
I showed 1/32" toe out left front, 3/32" toe in right front. 3/32" toe in both sides rear. Did not recheck camber, so sticking with shop -2.0 rear and -1.6 -1.7 front.


First adjustment was to rear only.
Set rear camber to -1.5 deg each side. Set toe in to 1/64" each side.

A few days later, adjusted front toe to zero both sides. Did not change shims, so camber shod still be -1.6 and -1.7. When I did the fronts, I'd set toe where I wanted it, recenter the steering wheel since it moved a tiny bit, then set it again, and make sure SMT said zero when I was finished.

I've restrung the car several times and remeasured and get the same numbers each time. The car drives straight, does not pull, everything feels good. Reducing the rear camber and resetting toe got rid of the slight rear-end wagging feeling I was getting when hitting dips on the highway.

So I guess if it's an alignment issue, my next question is which spec would cause this? There's no feeling of oversteer or understeer when TC intervenes. And these are all places I've driven before with no issue, the TC intervention is recent. Maybe it's a different unrelated issue?

I can double check the zero steering angle with a level.

 

[lUtriaNt]

on cloverleafs, on my old car, traction control would come on due to my tread being low on the tires. maybe its as simple as that?

 

[AltLogic]

In case you missed my past suggestion, check to make sure you don’t have a bad wheel bearing, bushing or control arm using the following method: Jack up one wheel at a time and check for movement of the wheel. Grab the top and bottom of the tire and try to twist it and make sure the camber is stable. Next grab the front and rear of the tire and make sure the toe is stable. Lock the steering wheel and keep in mind that the front tires will move with the steering wheel.

I chased a problem with my racecar where the car was unstable in left turns but stable in right turns. I checked the alignment, suspension bolt torques and wheel bearings like a crazy person to no avail. At the time I only checked the wheel bearings by trying to check for camber instability. I tried various camber, toe and shock settings. I replaced the bushings in the aftermarket upper control arm and tried switching to stock upper control arms. I spoke with the shock representative and told them about it and asked what the chances were the right rear shock had failed. He said that they never had a shock fail. Then I got serious. I ordered new bushings and a new wheel bearing after I finally found the problem. I checked the stability of the toe of the right rear and noticed I could easily muscle it a few degrees. I was so happy! It has been great for the 5 years since I fixed it.

 

[destructure00]

on cloverleafs, on my old car, traction control would come on due to my tread being low on the tires. maybe its as simple as that?

I'll post pics tomorrow, but I think I have plenty of tread to where this isn't an issue. Could try rotating rear to front since rears are new and see what happens, that's easy enough.

In case you missed my past suggestion, check to make sure you don’t have a bad wheel bearing, bushing or control arm using the following method: Jack up one wheel at a time and check for movement of the wheel. Grab the top and bottom of the tire and try to twist it and make sure the camber is stable. Next grab the front and rear of the tire and make sure the toe is stable. Lock the steering wheel and keep in mind that the front tires will move with the steering wheel.

I chased a problem with my racecar where the car was unstable in left turns but stable in right turns. I checked the alignment, suspension bolt torques and wheel bearings like a crazy person to no avail. At the time I only checked the wheel bearings by trying to check for camber instability. I tried various camber, toe and shock settings. I replaced the bushings in the aftermarket upper control arm and tried switching to stock upper control arms. I spoke with the shock representative and told them about it and asked what the chances were the right rear shock had failed. He said that they never had a shock fail. Then I got serious. I ordered new bushings and a new wheel bearing after I finally found the problem. I checked the stability of the toe of the right rear and noticed I could easily muscle it a few degrees. I was so happy! It has been great for the 5 years since I fixed it.

Will check all this tomorrow while rotating tires. Thanks for the ideas.

 

[Dolemite]

Pretty dumb but... also check tire pressures?

Don’t mean to derail things too hard but I had a few questions because I’m thinking of doing this after Tesla quoted me $302 to do a 4-wheel alignment recently. And shops around here are paranoid about Teslas.

• What system are you using?
• What’s your setup like? I.e. how are you reaching the alignment bolts w/ the car on the ground?
• How are you settling the car after making an adjustment with all the electronic nannies? Tow Mode?
• Most importantly... How long does this all this take you? Last time I did this on a Miata it took me 14 hours the day before an auto-x and I swore I’d never do it again, but I was dumber than I am now and wasn’t set up to do it well.

And what are you guys calling SMT?

 

[SlimJim]

Its the tires probably.
Put on a set of different tires of same brand and wear and test.

 

[destructure00]

Left side tires. Left tire in pic is rear, right is front.

Left rear tread:
7/32" outer edge
6/32" middle
5/32" inner edge

Left front tread:
5/32" outer edge
5/32" middle
5/32" inner edge

 

[destructure00]

Right side tires. Tire on right side of pic came off the rear.

Right rear tread:
7/32" outer edge
8/32" middle
7/32" inner edge

Right front tread:
5/32" outer edge
5/32" middle
5/32" inner edge

 

[destructure00]

In case you missed my past suggestion, check to make sure you don’t have a bad wheel bearing, bushing or control arm using the following method: Jack up one wheel at a time and check for movement of the wheel. Grab the top and bottom of the tire and try to twist it and make sure the camber is stable. Next grab the front and rear of the tire and make sure the toe is stable. Lock the steering wheel and keep in mind that the front tires will move with the steering wheel.

I chased a problem with my racecar where the car was unstable in left turns but stable in right turns. I checked the alignment, suspension bolt torques and wheel bearings like a crazy person to no avail. At the time I only checked the wheel bearings by trying to check for camber instability. I tried various camber, toe and shock settings. I replaced the bushings in the aftermarket upper control arm and tried switching to stock upper control arms. I spoke with the shock representative and told them about it and asked what the chances were the right rear shock had failed. He said that they never had a shock fail. Then I got serious. I ordered new bushings and a new wheel bearing after I finally found the problem. I checked the stability of the toe of the right rear and noticed I could easily muscle it a few degrees. I was so happy! It has been great for the 5 years since I fixed it.

Just checked all 4 corners and they are solid, no abnormal movement.

Pretty dumb but... also check tire pressures?

Don’t mean to derail things too hard but I had a few questions because I’m thinking of doing this after Tesla quoted me $302 to do a 4-wheel alignment recently. And shops around here are paranoid about Teslas.

• What system are you using?
• What’s your setup like? I.e. how are you reaching the alignment bolts w/ the car on the ground?
• How are you settling the car after making an adjustment with all the electronic nannies? Tow Mode?
• Most importantly... How long does this all this take you? Last time I did this on a Miata it took me 14 hours the day before an auto-x and I swore I’d never do it again, but I was dumber than I am now and wasn’t set up to do it well.

And what are you guys calling SMT?

All 4 tires are 41-42 cold. SMT = Scan My Tesla, a way to read a bunch of parameters from the car. Steering angle is one of those.

 

[destructure00]

Pretty dumb but... also check tire pressures?

Don’t mean to derail things too hard but I had a few questions because I’m thinking of doing this after Tesla quoted me $302 to do a 4-wheel alignment recently. And shops around here are paranoid about Teslas.

• What system are you using?
• What’s your setup like? I.e. how are you reaching the alignment bolts w/ the car on the ground?
• How are you settling the car after making an adjustment with all the electronic nannies? Tow Mode?
• Most importantly... How long does this all this take you? Last time I did this on a Miata it took me 14 hours the day before an auto-x and I swore I’d never do it again, but I was dumber than I am now and wasn’t set up to do it well.

And what are you guys calling SMT?

Here's what I do. Pull car into garage on top of my turn tables, zero steering angle.

Set up strings using a pair of jack stands:

Since I know the rear is inset by 17/64" (will describe how further below), I use a set of calipers to set distance from the string to the same point on each wheel. Front I adjust the jack stand location so the string covers up the 5" mark on my calipers:

Rear I set the dial to 17/64", then adjust the jack stand so that the string covers up the same 5" mark. Have to do multiple measurements and adjustments front and rear to get it exact.

Once it's set, I measure distance from outer edge of the wheel to the string at the front and rear of the wheel.

This is the left front, front and rear edges both show 1/64" on the dial, so zero toe. Would take multiple measurements front and rear to make sure I didn't push the string out a bit while measuring one or the other.

 

[destructure00]

For adjustments, I do it with the car on the ground. Front tie rods I can reach by laying under the front bumper, or reaching through the spokes on the wheel.

Rear MPP arms are accessible through the wheels spokes too, at least on the 20s.

I also made some poor man's turn tables to put under the tires when adjusting toe. Bought 4 small sheets of clear plastic at Home Depot and sandwiched some grease between the sheets. They seem to work well, I have to be careful when rolling the car on or off the sheets as any power will shoot the upper sheet out.

 

[destructure00]

To find out front vs rear track width, I set up strings on both sides of the car and made adjustments until I got same distance string-to-string in front of and behind the car, as well as same distance front wheel face to string on both sides, and rear wheel face to string both sides. Took a long time to get this right, but only needs to be done once.

 

[Dolemite]

Awesome - thanks for the thorough explanation & pics! Truly a poor man's alignment... and presumably still does a better job than most of the shops. I guess there are some functional benefits to the 20s.

I used to use the 4-wheel alignment system from this company:

STORE - Tenhulzen Automotive | WheelAlignmentTools.com

Top-notch product, but flawed in concept IMO. My Miata had double wishbones all around, so 4 eccentric bolts per corner - 16 in total. Adjusting one bolt would affect every other measurement on that corner... huge hassle. Plus the car was very low so it was an absolute nightmare getting in there. In my experience, the worst part was that adjusting camber (maybe even toe?) tends to shift the car in relation to the string square. Every time that happens, you gotta re-square. That's why I'm *contemplating* whether something like this would be a better solution:

SmartStrings — Smart Racing Products

The only thing that worked well was the camber gauge, and it looks like they've released a better one that you can hook onto the wheel since then. Probably makes life way easier. I'm assuming you're using something similar?

 

[destructure00]

Awesome - thanks for the thorough explanation & pics! Truly a poor man's alignment... and presumably still does a better job than most of the shops. I guess there are some functional benefits to the 20s.

I used to use the 4-wheel alignment system from this company:

STORE - Tenhulzen Automotive | WheelAlignmentTools.com

Top-notch product, but flawed in concept IMO. My Miata had double wishbones all around, so 4 eccentric bolts per corner - 16 in total. Adjusting one bolt would affect every other measurement on that corner... huge hassle. Plus the car was very low so it was an absolute nightmare getting in there. In my experience, the worst part was that adjusting camber (maybe even toe?) tends to shift the car in relation to the string square. Every time that happens, you gotta re-square. That's why I'm *contemplating* whether something like this would be a better solution:

SmartStrings — Smart Racing Products

The only thing that worked well was the camber gauge, and it looks like they've released a better one that you can hook onto the wheel since then. Probably makes life way easier. I'm assuming you're using something similar?

Yeah I bought the Tenhulzen front toe plates with the integrated camber gauge. I gave up on the toe plates because they only measure total toe, not individual per side. But still using the camber gauge.

Regarding camber, I set that separately before stringing the car up for the reason you mention above, don't want the car to shift. So I'll set camber, pull the car out and back in to the garage, then set up for toe as described above. And when I set toe, I've been doing one corner at a time too, then moving the car out/in and re-setting the strings.

 

[Dolemite]

Yeah I bought the Tenhulzen front toe plates with the integrated camber gauge. I gave up on the toe plates because they only measure total toe, not individual per side. But still using the camber gauge.

Regarding camber, I set that separately before stringing the car up for the reason you mention above, don't want the car to shift. So I'll set camber, pull the car out and back in to the garage, then set up for toe as described above. And when I set toe, I've been doing one corner at a time too, then moving the car out/in and re-setting the strings.

Exactly - that's why I went straight for the 4-wheel. Doesn't make sense to me how people successfully use the toe plates for anything.

 

[destructure00]

Exactly - that's why I went straight for the 4-wheel. Doesn't make sense to me how people successfully use the toe plates for anything.

Agreed, now that I've actually tried it lol.

That smart strings thing looks interesting, I'll have to go watch a video on how it gets set up. Have you tried to 4 wheel system on the Model 3?

 

[Dolemite]

Agreed, now that I've actually tried it lol.

That smart strings thing looks interesting, I'll have to go watch a video on how it gets set up. Have you tried to 4 wheel system on the Model 3?

Nope - got traumatized & sold it a while ago & haven't done anything alignment-related, since. The smart strings are a lot of money for something that looks like it's been made from scrap... if I find the time, I may try to DIY something that works similarly. If Tesla wants $300, and everyone else is terrified to touch the car, it may be a sensible option if I can bang out an alignment in <2 hours...

 

[destructure00]

Nope - got traumatized & sold it a while ago & haven't done anything alignment-related, since. The smart strings are a lot of money for something that looks like it's been made from scrap... if I find the time, I may try to DIY something that works similarly. If Tesla wants $300, and everyone else is terrified to touch the car, it may be a sensible option if I can bang out an alignment in <2 hours...

Biggest thing for me was just getting the right numbers for track width. Now that that's done, setting up the strings is easy. Probably still would take me longer than 2 hours to do all 4 wheels though.