Performance Model 3: Excited or Disappointed?

[gambit48]

Bigger brakes don't make the car any "safer" in normal use... they don't do anything useful at all (besides make brake repairs more expensive) outside of a race track or the chase scene from a Jason Bourne film.

A lot of Hondas would beg to differ. The Odyssey, Ridgeline, and Pilot were all originally modified from the Accord. And apparently, they worked off of the Accord brakes instead of designing based on the increased mass. This was ok with the original Odyssey as that thing was tiny. Now... The brakes being too small is a very annoying issue for Odyssey, Ridgeline, and Pilot owners now. There's premature wear, failure, etc. Likely decreased braking performance after a hard stop or two. I've had to replace rotors an annoying amount of time on two of those models, as compared to my current sedan for example.

Undersized brakes can make a difference even in "normal" usage.

 

[Brando]

<Nostalgia> informative (many testing tracks around the world for vehicles)

"To ensure that the Tesla Roadster is as safe as possible in extreme conditions, we have just finished putting one of our Engineering Prototypes through an extensive test schedule at the Continental Proving Ground in Arvidsjaur, Sweden. The proving ground is in a beautiful location on and around a frozen lake about 60 miles from the Arctic Circle."

Slip-Sliding Away
Iain Morrison, Test & Validation Engineer April 3, 2007

Slip-Sliding Away

 

[Knightshade]

A lot of Hondas would beg to differ.

Then they'd be wrong too.

Physics doesn't change with brand of car.

Undersized brakes can make a difference even in "normal" usage.

To my knowledge every western car produced in the last couple decades can engage ABS/lock up the brakes... at which point bigger brakes do literally nothing to stop a car any faster.

The only way to stop shorter is stickier tires.

Read the pulp friction article for the math and physics of why.

 

[kbM3]

Lets hope that Performance is worth the money. I appreciate you comparing the Model 3 to its competition and not to cars outside of its class.

I’m just trying to interpret Elon’s tweet. My guess is he’s referring to BMW M3 et. al.

I think the key omission is ludicrous - it seems like this will be added with the air suspension next year but no one seems to be mentioning this.

Ludicrous should be sub 3 seconds 0-60 (as defined by a speculating Ryan MCCaffrey), it seems odd to me that no one is concerned with the next gen model 3 doing to the P85 what the P90DL and subsequent model did thereafter.

Elon has said that the battery pack of the Model 3 is too small to achieve Model S Ludicrous acceleration.

 

[sammyfan711]

I’m just trying to interpret Elon’s tweet. My guess is he’s referring to BMW M3 et. al.



Elon has said that the battery pack of the Model 3 is too small to achieve Model S Ludicrous acceleration.

Bummer! Last I heard was his 2016 tweet that confirmed ludicrous would be an option.

 

[kbM3]

Bummer! Last I heard was his 2016 tweet that confirmed ludicrous would be an option.

True, just not P100D ludicrous level.

 

[bxr140]

Why worry about the suspension and brakes? If it beats everything in its class on the track, isn’t that what matters?

Except that...the whole package is part and parcel of being best in class, and that package of course includes suspension and brakes engineered and tuned for a performance environment. The Model 3's power and CG advantage will only go so far in a true performance environment, regardless if you're talking the local autocross parking lot or the Nordschleife.

...every western car produced in the last couple decades can engage ABS/lock up the brakes... at which point bigger brakes do literally nothing to stop a car any faster..

"Better" and "Safer" are metrics that span a broader range than a vehicle's ability to perform a single emergency stop. For instance [all else equal] larger brakes provide more consistent feel and more finite control, both of which come in to play in all road situations, including emergency stops (where the finer control in the otherwise all-else-equal ABS system will better manage the tire slip).

 

[kbM3]

Except that...the whole package is part and parcel of being best in class, and that package of course includes suspension and brakes engineered and tuned for a performance environment. The Model 3's power and CG advantage will only go so far in a true performance environment, regardless if you're talking the local autocross parking lot or the Nordschleife.



"Better" and "Safer" are metrics that span a broader range than a vehicle's ability to perform a single emergency stop. For instance [all else equal] larger brakes provide more consistent feel and more finite control, both of which come in to play in all road situations, including emergency stops (where the finer control in the otherwise all-else-equal ABS system will better manage the tire slip).

Once again. If it has best-in-class track performance, the rest takes care of itself.

 

[Knightshade]

"Better" and "Safer" are metrics that span a broader range than a vehicle's ability to perform a single emergency stop. For instance [all else equal] larger brakes provide more consistent feel and more finite control, both of which come in to play in all road situations, including emergency stops (where the finer control in the otherwise all-else-equal ABS system will better manage the tire slip).

... no, they don't.

An emergency stop is when you slam the brake pedal as hard as you can, as quickly as you can.

It's the exact opposite of a situation where "more consistent feel" or "more finite control" make any difference.

The only thing that matters in an emergency stop is how short a distance you can stop the car in.

Which bigger brakes doesn't help with. At all.

Stickier tires is what does that.

Because ultimately the tires, not the brakes, actually stop the vehicle.


Brake upgrades can be useful on a track car because there adjusting the 'feel' of the system can impact racing performance where you're having to make a lot of varied, and repeatedly, brake inputs... but the car still won't ever stop any shorter than it did the first time with stock brakes can in a single panic stop even then.


I'd again encourage folks unaware of these facts to read this:
GRM Pulp Friction

 

[gambit48]

There's a lack of proper size and cooling in the Honda models I've mentioned. Things might be ok with one emergency stop. Repeated braking, even if they're not necessarily emergency stops, can still trigger brake fade.

If they've overloaded the car, are going down a mountain, or just not a perfect car owner/driver like they should be, that brake fade can even lead to failure. They warp way too easily right now.

Honda's already modified the brakes once. The consensus is that it helps, but they still need to go further. They really need to upsize it and allow for better heat dissipation.

Even with ABS, if the brakes weren't properly engineered to be the right size for the vehicle, it's not gonna be as safe.

 

[Garlan Garner]

... no, they don't.

An emergency stop is when you slam the brake pedal as hard as you can, as quickly as you can.

It's the exact opposite of a situation where "more consistent feel" or "more finite control" make any difference.

The only thing that matters in an emergency stop is how short a distance you can stop the car in.

Which bigger brakes doesn't help with. At all.

Stickier tires is what does that.

Because ultimately the tires, not the brakes, actually stop the vehicle.


Brake upgrades can be useful on a track car because there adjusting the 'feel' of the system can impact racing performance where you're having to make a lot of varied, and repeatedly, brake inputs... but the car still won't ever stop any shorter than it did the first time with stock brakes can in a single panic stop even then.


I'd again encourage folks unaware of these facts to read this:
GRM Pulp Friction

Bigger brakes mean more pad on the rotor. That makes a difference if the tires can handle it.

If your tires grip (without slipping) all the way through stomping on the brakes....then more brakes would help you. Just make sure you have applied adequate polygrip.

Same holds true for acceleration. If your tires don't slip....put in a bigger electric motor.

If your tires start to slip at that point...….remove some air. LOL

 

[Knightshade]

Bigger brakes mean more pad on the rotor. That makes a difference if the tires can handle it.

Which no street tire can on any modern vehicle.

If your tires grip (without slipping) all the way through stomping on the brakes....then more brakes would help you.

Which isn't true on any Tesla- nor on basically any western production car in the last decade or two at least.


Or to put it another way-

If you can engage ABS by slamming down the brake pedal, which all Teslas (and everything else currently made) can- then more brakes won't help.

Which is why folks insisting the Model 3 needs "more brakes for safety" are mistaken.

if they want to stop shorter they need better tires, not more brakes.

(and even with the stickiest street-legal tires available the stock tesla brakes will engage ABS- so even then "more brakes" won't help in street use)

 

[Garlan Garner]

Which no street tire can on any modern vehicle.




Which isn't true on any Tesla- nor on basically any western production car in the last decade or two at least.


Or to put it another way-

If you can engage ABS by slamming down the brake pedal, which all Teslas (and everything else currently made) can- then more brakes won't help.

Which is why folks insisting the Model 3 needs "more brakes for safety" are mistaken.

if they want to stop shorter they need better tires, not more brakes.

(and even with the stickiest street-legal tires available the stock tesla brakes will engage ABS- so even then "more brakes" won't help in street use)

You should tell Elon to NOT put bigger brakes on the Performance Model then.

He must be missing something then - maybe you can educate him. Especially since a brake is a brake is a brake....and its all in the tires.

Elon Musk on Twitter

 

[Daniel in SD]

You should tell Elon to NOT put bigger brakes on the Performance Model then.

He must be missing something then - maybe you can educate him. Especially since a brake is a brake is a brake....and its all in the tires.

Elon Musk on Twitter

There seems to be people talking past each other in this thread. You put bigger brakes on the performance model to make it compete on the TRACK. The Model 3 brakes are certainly big enough for street use. They have more than enough power to lock up the wheels and therefore bigger brakes will do nothing to stop you faster.
I agree that some cars have brakes that are undersized for aggressive street driving and warp too easily. Many people don't know to downshift when going down a mountain and cook their brakes quickly. It seems like this could be a big issue in the Model 3 if regen is disabled (either through the setting, temperature, or the battery being full) since it's such a heavy aerodynamic car. They should probably add some sort of warning that uses an estimate of brake temperature.

 

[Garlan Garner]

There seems to be people talking past each other in this thread. You put bigger brakes on the performance model to make it compete on the TRACK. The Model 3 brakes are certainly big enough for street use. They have more than enough power to lock up the wheels and therefore bigger brakes will do nothing to stop you faster.
I agree that some cars have brakes that are undersized for aggressive street driving and warp too easily. Many people don't know to downshift when going down a mountain and cook their brakes quickly. It seems like this could be a big issue in the Model 3 if regen is disabled (either through the setting, temperature, or the battery being full) since it's such a heavy aerodynamic car. They should probably add some sort of warning that uses an estimate of brake temperature.

I'm only replying to the statement that bigger brakes make no sense since stopping is all in the tires. <------I'm being sarcastic there.

 

[AviP]

Performance has 3 basic components: acceleration, deceleration and handling. Increasing the acceleration and calling it performance is a joke if the deceleration or handling cannot be improved. So stronger brakes are a must. And some improvement to the suspension or tires or downforce to improve the handling is a must. Then you have a performance model. Until then, it's just an expensive dragstrip toy that a modified Honda Civic could beat.

 

[Garlan Garner]

Performance has 3 basic components: acceleration, deceleration and handling. Increasing the acceleration and calling it performance is a joke if the deceleration or handling cannot be improved. So stronger brakes are a must. And some improvement to the suspension or tires or downforce to improve the handling is a must. Then you have a performance model. Until then, it's just an expensive dragstrip toy that a modified Honda Civic could beat.

No...no....

The P100D is NOT all of those things on the Model S. Acceleration (performance / Ludicrous ) is selling on the Model S. Call that what you want, however Tesla calls it performance......and its selling - which makes it a profitable "joke" ( your terminology).

I'm going to stick with the term Performance ( as it is defined by Tesla ) - and I'm not going to mind at all calling it my Environment Saving Performance Toy (unlike the Civic - which by the way is not even in the same class a Model 3). Which - ( in keeping with the thread title ) makes me Excited.

 

[AviP]

Which is why folks insisting the Model 3 needs "more brakes for safety" are mistaken.

if they want to stop shorter they need better tires, not more brakes.

(and even with the stickiest street-legal tires available the stock tesla brakes will engage ABS- so even then "more brakes" won't help in street use)

A 5th generation Dodge Viper stops in ~90 feet. The Model 3 is 10% heavier but takes ~40 feet more. It's all brakes and tires. Wimpy tires will give you a reduced contact patch. And wimpy rotors / calipers will increase the time-to-lock-up and ABS to engage translating to longer braking distances. It's simple physics.

So yes, put in any of the following options and you will get a shorter stopping distance.
- Wider summer tires
- Bigger rotors
- Bigger pistons or calipers.

 

[bxr140]

Once again. If it has best-in-class track performance, the rest takes care of itself.

Got it, I misunderstood. Sounds like we're on the same page that it is UBER important to consider brakes and suspension for on-track performance.

If you can engage ABS by slamming down the brake pedal, which all Teslas (and everything else currently made) can- then more brakes won't help.

Again, that's not true. I encourage you to read up on the fundamentals of ABS. Short story is that ABS works by precisely controlling wheel speed relative to vehicle speed, which--most importantly--controls tire slip. It is explicitly not a binary thing--It is in the grey area between slip and no-slip that a tire enables the greatest braking force. Similar to how adding a bigger steering wheel on a vehicle, a longer lever arm on a torque wrench, or any other similar situation where a bigger thing adds more precise control, larger brakes [in an all else equal system] will allow the ABS to more precisely control that tire slip and thus better maximize traction. Which of course reduces braking distance.

Its physics, as it were.

 

[kbM3]

A 5th generation Dodge Viper stops in ~90 feet. The Model 3 is 10% heavier but takes ~40 feet more. It's all brakes and tires. Wimpy tires will give you a reduced contact patch. And wimpy rotors / calipers will increase the time-to-lock-up and ABS to engage translating to longer braking distances. It's simple physics.

So yes, put in any of the following options and you will get a shorter stopping distance.
- Wider summer tires
- Bigger rotors
- Bigger pistons or calipers.

Does the Dodge Viper do that in a CR test , which include varied road surfaces including wet?