Braking Under "Spirited" Driving

[borski]

from the videos that I've seen the brakes on the car are not really great. regen is for slowing down at lower speeds, I'm talking about hard braking from speed

The brakes are fine for hard braking from speed. Not as good as the Sapphire, but these massive calipers will stop you with perfect stability (on the 21s) given enough distance (which it requires a little more of, given the weight).

No reviewer thus far has complained about the brakes at all other than to wish they had a slightly shorter stopping distance. But nobody has complained about the feel or stability, to my knowledge.

 

[Steveinarizona]

Moral of the story- Don’t drive over 100 mph.

But that's no fun.

 

[Steveinarizona]

The brakes are fine for hard braking from speed. Not as good as the Sapphire, but these massive calipers will stop you with perfect stability (on the 21s) given enough distance (which it requires a little more of, given the weight).

No reviewer thus far has complained about the brakes at all other than to wish they had a slightly shorter stopping distance. But nobody has complained about the feel or stability, to my knowledge.

That is why I suspect that the OP may actually have a problem,

 

[Cossa]

Right, that makes perfect sense, the strange feeling is that it seems like almost nothing happens when I take my foot off the pedal at that speed. If I take my foot off the pedal at 70mph it feels like I've just stepped on the brake. I get that the battery can't take all that power over 100mph, but my expectation would be that regen applies roughly the same amount of deceleration force, taking the same amount of power to the battery, whether at 70 or 145. Just like putting the same pressure on the brake pedal should feel like roughly the same deceleration force regardless of your speed.

I’d be interested to know what the regen kW looks like via the API at different speeds (some of which may be in Mexico).

 

[Cossa]

I have definitely also noticed much less regen when I let off the accelerator at higher speeds. I keep my regen on High but there is a very real change in decelerating at freeway speeds now.

I’ve suspected regen has changed in the last couple OTA updates. It seems like regen is less forceful.

 

[truth.b]

I got my AGT on 20's the past Dec so I haven't had a chance to fully explore the limits of the handling and braking due to the cold weather, but these are my preliminary thoughts so far.

1. This car is approx ~5,200 lbs without passengers; that is very close to the weight of a Ford F-250 super duty. Think about that, a dang work truck.
- The speed/acceleration and ride quality really hide how much mass is being moved from point A to B.

2. I've messed around with various styles of driving and I know the regen braking is extremely dynamic, which make is difficult to trail brake with this car. I also experience weird vibrations after heavy acceleration. Maybe its a motor fan or cooling pump... not sure about that one yet.

3. Although the 20's and 21's are "summer tires" they are still EV tires... which aren't as grippy as a good performance or all-season tire. Stopping power is a function of tires first with brakes being appropriately sized for stopping repeatability.

4. I have a growing suspicion that some of the tricks Lucid used in the name of "EV efficiency" add subtle nuances to this vehicle driving dynamics. Personally I like it but I can see how it could take some getting use to.
- For instance I know at slow to moderate speeds (sub 50mph) there is least a 1/2" of dead space of pedal movement before I feel the friction brakes add noticeable deceleration.

Link >> https://www.motortrend.com/features/2022-lucid-air-luxury-ev-chassis-deep-dive/

Lastly, I have a corvette that I've been taking to the track since roughly 2014, and this sedan probably would run circles around it in a head-to-head with proper tires and a brake fluid change. The only problem is the weight and the heat generated by the batteries. After having my AGT for a about week I had created the perfect sports car EV in my head. A single motor 600HP 2-seater at 4300lbs with a 65 kWh battery that can get roughly 300miles of range with an aggressive DC fast charging curve. That car would be so much fun but alas I know there is NO business case for something like that.

 

[kort6776]

The brakes are fine for hard braking from speed. Not as good as the Sapphire, but these massive calipers will stop you with perfect stability (on the 21s) given enough distance (which it requires a little more of, given the weight).

No reviewer thus far has complained about the brakes at all other than to wish they had a slightly shorter stopping distance. But nobody has complained about the feel or stability, to my knowledge.

the testing I have seen is that most cars at this level will stop the car from 60 mph in 100-110 feet, it takes the Lucid 130+ feet to stop. I haven't seen many if any reviewers on places like youtube perform any sort of braking tests

 

[segbrk]

the testing I have seen is that most cars at this level will stop the car from 60 mph in 100-110 feet, it takes the Lucid 130+ feet to stop. I haven't seen many if any reviewers on places like youtube perform any sort of braking tests

But are most cars “at this level” 5000lbs? If not, 20 extra feet seems pretty good for the non-track version of the car.

 

[RM-S8]

I can’t say I’ve noticed any difference in regen on the highway.

Same here.

 

[Pragmatic]

The longer stopping (130 from 60 vs 110) is mostly tires. If you tested an Air on grippy non-EV tires I'm sure distance would be shorter.

 

[hmp10]

No reviewer thus far has complained about the brakes at all other than to wish they had a slightly shorter stopping distance. But nobody has complained about the feel or stability, to my knowledge.

Edmunds did in that ridiculous match-up between an Acura NSX on summer tires and a much heavier Lucid Air on 19" all-season tires.

But that was Edmunds . . . so safely ignored as a reputable source.

 

[xponents]

Edmunds did in that ridiculous match-up between an Acura NSX on summer tires and a much heavier Lucid Air on 19" all-season tires.

But that was Edmunds . . . so safely ignored as a reputable source.

I can't wait for their Honda Civic vs Huracan STO matchup... "the Civic is a bad car because of how much longer it takes to stop!"

 

[hmp10]

from the videos that I've seen the brakes on the car are not really great. regen is for slowing down at lower speeds, I'm talking about hard braking from speed

I think apples are getting mixed up with the oranges in some of this discussion. Stopping distance and brake overload (fading, overheating) are separate issues.

It is generally recognized that the Air has a longer-than-everage stopping distance from 0-60 and 0-70. This is largely a function of the weight of the car (driven by the battery pack), the relative narrowness of the tires (driven by aerodynamic/range concerns), and tire rubber compounds that make some trade-offs in grip to reduce rolling resistance. Most EVs intended for daily use have these same traits to a greater degree than their ICE counterparts.

The Air (except for the Sapphire) is not a track car, although its handling prowess can tempt us into thinking otherwise. Stopping distance should always be front and center on the mind of anyone driving this car at very high speeds.

The brake overload issue, however, only shows up in extreme sustained driving, as in track use or repeated drag racing (as was the case with Edmunds). And this is use beyond the car's design parameters . . . and use that voids the car's warranty, by the way.

If, however, you look at the Air that Lucid designed for the track and extreme driving -- the Sapphire -- you will find some of the most robust and effective brakes in the world on that car.

 

[kort6776]

If, however, you look at the Air that Lucid designed for the track and extreme driving -- the Sapphire -- you will find some of the most robust and effective brakes in the world on that car.

@$250k? the saphire is what as known as a halo car.
if more robust braking is possible it should have been added or optional on all the levels in the lineup.

 

[hydbob]

@$250k? the saphire is what as known as a halo car.
if more robust braking is possible it should have been added or optional on all the levels in the lineup.

The standard Air brakes are excellent for what the car is designed for.

 

[Pragmatic]

Jason Camissa has spoken several times on the perception of inferior brakes in high powered EVs. Since these cars are the first to accelerate as quickly or more quickly than they brake, the driver has a tendency to believe the brakes are inadequate. Because how ICE cars accelerate and brake they always stop much quicker than they go.

Car and Driver data -
Porsche 911GT3 RS 0 - 100 in 660 feet; 100 - 0 in 265 ft

Kia EV6 GT 0- 100 702 feet 100 - 0 in 322

I can't find equivalent data on Air's or Teslas

 

[xponents]

Jason Camissa has spoken several times on the perception of inferior brakes in high powered EVs. Since these cars are the first to accelerate as quickly or more quickly than they brake, the driver has a tendency to believe the brakes are inadequate. Because how ICE cars accelerate and brake they always stop much quicker than they go.

Car and Driver data -
Porsche 911GT3 RS 0 - 100 in 660 feet; 100 - 0 in 265 ft

Kia EV6 GT 0- 100 702 feet 100 - 0 in 322

I can't find equivalent data on Air's or Teslas

Lucid Air GT braking stats only:
Braking, 70–0 mph: 193 ft
Braking, 100–0 mph: 385 ft

Model S Plaid (non-track pack)
Braking, 70–0 mph: 150 ft
Braking, 100–0 mph: 284 ft

I always hate when people call the Plaid's brakes trash, because that is absolutely not true. When you use it for its intended purpose (not track driving, repeated hard stops), they actually have a very good stopping distance. The only reason people say the stock Plaid brakes are bad is because they fade with track use and they "feel" like the brakes are bad since the car accelerates harder than it decelerates (which is very rare, or it used to be). The same goes for the Air which I consider a grand tourer car vs a dedicated sports car (think of a Aston DB vs a Aston Vantage).

 

[hmp10]

@$250k? the saphire is what as known as a halo car.
if more robust braking is possible it should have been added or optional on all the levels in the lineup.

Tesla's "halo" car, the Model S Plaid, was introduced with the same brakes as the long-range Model S. The car was excoriated in the press for being under-braked under hard use. Only under the floodlight of the bad press did Tesla finally introduce its $20,000 track package with upgraded brakes.

If cost were no object, there is not a mainstream car on the market that could not have been fitted with better brakes.

However, if you can point me to another car at or under a quarter million dollars that has the state-of-the-art continuously woven carbon ceramic brake discs of the Sapphire, I'd like to know about it.

I see you own a Taycan. At more than 350 pounds lighter than a Sapphire, the Taycan's 0-60 stopping distance is 3 feet longer (109 vs 112 feet). Why wouldn't Porsche have put better brakes on the Taycan?

 

[Cosmo Cruz]

Those who've tasted carbon/ceramic brakes:
way overkill for the way I drive (no track), but my goodness they are so worth it.

 

[hmp10]

Lucid Air GT braking stats only:
Braking, 70–0 mph: 193 ft
Braking, 100–0 mph: 385 ft

Model S Plaid (non-track pack)
Braking, 70–0 mph: 150 ft
Braking, 100–0 mph: 284 ft

I always hate when people call the Plaid's brakes trash, because that is absolutely not true. When you use it for its intended purpose (not track driving, repeated hard stops), they actually have a very good stopping distance. The only reason people say the stock Plaid brakes are bad is because they fade with track use and they "feel" like the brakes are bad since the car accelerates harder than it decelerates (which is very rare, or it used to be). The same goes for the Air which I consider a grand tourer car vs a dedicated sports car (think of a Aston DB vs a Aston Vantage).

A good bit of these braking distance differences has to do with tire sizes and vehicle weight, not with the brakes themselves.

The Air GT 21" tire widths are 245mm front and 265mm rear. The Plaid's 21" tire widths are 265mm front and 295mm rear.

And the Model S Plaid weighs 386 pounds less than the Air GT.