2023 plaid x high speed hard braking stability issue

[LoneStarrPlaid]

I have had the x for about a month now and put about 700 miles on it. It is a 23 plaid X with the 20 inch wheels all season tires.

The problem is under hard braking from 100+ mph. the car wants to sway back-and-forth or even switch lanes on me, causing me to not brake nearly as hard. I have no control over the vehicle under hard braking.

Is this happening to anybody else? I am going to bring it in for service but nothing is broken on the car. Tires are good. Pressure is 45 all around cold. Suspension in low or very low / sport.

 

[Tam]

I have had the x for about a month now and put about 700 miles on it. It is a 23 plaid X with the 20 inch wheels all season tires.

The problem is under hard braking from 100+ mph. the car wants to sway back-and-forth or even switch lanes on me, causing me to not brake nearly as hard. I have no control over the vehicle under hard braking.

Is this happening to anybody else? I am going to bring it in for service but nothing is broken on the car. Tires are good. Pressure is 45 all around cold. Suspension in low or very low / sport.

I am not sure but I think driving and braking in high speed 100MPH+ is not the same as normal speed under 90MPH.

 

[LoneStarrPlaid]

I am not sure but I think driving and braking in high speed 100MPH+ is not the same as normal speed under 90MPH.

What do you mean? lol

 

[Tam]

What do you mean? lol

A tiny maneuver in driving and braking in 100MPH+ could cause crashes.

 

[IvesSM]

I have had the x for about a month now and put about 700 miles on it. It is a 23 plaid X with the 20 inch wheels all season tires.

The problem is under hard braking from 100+ mph. the car wants to sway back-and-forth or even switch lanes on me, causing me to not brake nearly as hard. I have no control over the vehicle under hard braking.

Is this happening to anybody else? I am going to bring it in for service but nothing is broken on the car. Tires are good. Pressure is 45 all around cold. Suspension in low or very low / sport.

Sounds like your brakes are fading, possibly due to high temperature buildup. With the loss of control it sounds like one wheel or one side fading out.

The excessive heat may be causing the breaker fluid to boil. Are the brakes spongy after the hard stop?

QUESTION: is regen turned on?

From another thread here talking about the same thing:

Model X Plaid : Track Package and CCBs

Been really interested in the track package and CCBs available on the S Plaid. Any thoughts on will it be available on the X Plaid?

teslamotorsclub.com

" I ordered some upgraded brakes, lines and Castrol fluid and wheels not to do track work, but because they are spectacularly not fit for purpose from the manufacturer... Do one high speed slow down and then see what I mean... But yeah"

 

[LoneStarrPlaid]

Sounds like your brakes are fading, possibly due to high temperature buildup. With the loss of control it sounds like one wheel or one side fading out.

The excessive heat may be causing the breaker fluid to boil. Are the brakes spongy after the hard stop?

QUESTION: is regen turned on?

From another thread here talking about the same thing:

Model X Plaid : Track Package and CCBs

Been really interested in the track package and CCBs available on the S Plaid. Any thoughts on will it be available on the X Plaid?

teslamotorsclub.com

" I ordered some upgraded brakes, lines and Castrol fluid and wheels not to do track work, but because they are spectacularly not fit for purpose from the manufacturer... Do one high speed slow down and then see what I mean... But yeah"

It’s not brake fade. It’s the first time applying brakes. Regen stops the car 99% of the time.

 

[IvesSM]

Okay, not brake fade.

So this is not on a track, but on public roads, your doing 100+and you get in a bind and need to do a HARD BRAKE CHECK and you lose control. As you described this happens when you do a HARD BRAKE CHECK from speed the first time.

A real race car driver will never go full tilt right out of the gate. That's why they have warm up laps.

The first thing I would replace is the driver.

These cars @ speed in the hands of an inexperienced driver are a threat to everyone in the car and on the road.

 

[LoneStarrPlaid]

Okay, not brake fade.

So this is not on a track, but on public roads, your doing 100+and you get in a bind and need to do a HARD BRAKE CHECK and you lose control. As you described this happens when you do a HARD BRAKE CHECK from speed the first time.

A real race car driver will never go full tilt right out of the gate. That's why they have warm up laps.

The first thing I would replace is the driver.

These cars @ speed in the hands of an inexperienced driver are a threat to everyone in the car and on the road.

lol old man. Not my first rodeo. I’ve had several high hp car and have never experienced anything remotely close to this. The car has no stability under braking from high speed.

 

[IvesSM]

@LoneStarrPlaid right you are, your right on with "old man" tag, and proud of it!

After running the open roads in Europe for over 10 years on both 4 wheels and 2 I've never encountered a loss of control while unexpectedly getting into a hard braking situation. I'm also not going to test it out with my own 2023 MX LR. Not a chicken, just not worth the risk. I turned in my helmet years ago.

If you want to rip down the roads maybe you should have gotten a Model S Plaid rather than an almost 2,000 lb heavier car.

Good luck with your PLAID. Keep us posted on what you find.

 

[E90alex]

Bad suspension design and bad/inadequate braking system on a car with insane acceleration and speed will yield poor results at the limit.

 

[MrSlowEv]

The only issue you will have when bringing it into the service center is that they will not take your car over the speed limit to duplicate your concern. They will only check the braking operation at the maximum legal speed limit on the freeway because it’s a major liability. Just want to give you a heads up.

I’m just speaking off of my experience with my previous Tesla that had a vibration at 80mph. They were only able to check it at 65mph. I was also a technician for another major car manufacturer for 12 years and I was only able to verify customer concerns at the legal speed limit. I drive my Personal cars faster though.

 

[Ray_R]

New brake pads typically need to be bedded before hard use. How often and how hard had you used your brakes prior to this event?

 

[LoneStarrPlaid]

New brake pads typically need to be bedded before hard use. How often and how hard had you used your brakes prior to this event?

I bed them in the week I got the car. Several stops from 50-5 then a cooldown.

 

[LoneStarrPlaid]

Anybody else having this issue? I had the car aligned at an independent shop to n2utive specs. Still having very unsettling behavior when brakes are applied above 120mph. At freeway speeds the car acts normal. Perhaps it needs upgraded sway bars. I’m just curious if anyone else is experiencing this…we’ve all had high perf cars if you bought a plaid. So I know what to expect from braking at high speeds. The plaid wants To start switching lanes when the brakes are pressed at high speeds.

 

[LoneStarrPlaid]

Do my abs sensor lines look ok? Alignment shop said the look damaged to them. Car is throwing no errors.

 

[MrSlowEv]

Do my abs sensor lines look ok? Alignment shop said the look damaged to them. Car is throwing no errors.View attachment 995661

It’s odd that there are wires exposed on the harness for the sensor. I also can’t tell what that strand is that is sticking out of the wire harness. I would think that if one of those wires are broken that there would be a DTC stored for it and you would be getting warnings. Have you ever gotten any warnings lights at all during the unstable braking? Also, do you feel the ABS activating when your issue occurs? Do you hear any audible sounds?

 

[LoneStarrPlaid]

It’s odd that there are wires exposed on the harness for the sensor. I also can’t tell what that strand is that is sticking out of the wire harness. I would think that if one of those wires are broken that there would be a DTC stored for it and you would be getting warnings. Have you ever gotten any warnings lights at all during the unstable braking? Also, do you feel the ABS activating when your issue occurs? Do you hear any audible sounds?

Nope. No warnings. Car brakes fine under 100. But above that is unsettling, unlike anything I’ve experienced in my 20+ years of driving performance cars.