P3D Add performance checkbox removes on new custom orders

[Knightshade]

You're right, it is pretty basic physics. Its easier to explain to the lay person that way. We'll get to that later in my response. You're also right, shortest possible stopping distance is limited by your tires. But that isn't what I commented. It was your assertion that only the tires matter.

Because that remains a fact.

You can't stop shorter than the tires are capable of no matter how much you upgrade the brakes

There are a whole host of reasons why that's not true.

It's weird you admit you are limited by the tires and then deny you're limited by the tires...

Wrong again: Stopping Distance Retest After an ABS Firmware Update - 2017 Tesla Model 3 Long-Term Road Test

"Our initial 2017 Tesla Model 3 full-ABS panic-stop measurement of 133 feet was indeed below average.

you realize you just confirmed I was right and you lied right?

They're saying it was below average for "comparable cars" (which is a stupid comparison anyway- since they didn't have the same tires)

In fact, they POINT THAT OUT IN THE NEXT SENTENCE YOU QUOTE-

But it didn't seem outrageous, especially given the characteristics of the standard 18-inch tires. They're hard (with a treadwear rating of 500), they run at an abnormally high tire pressure (45 psi), and their 235 mm tread width isn't generous considering the car's 3,884 pounds of weight. It all seemed to fit

Huh- look- they TOO note the tires are the relevant thing.

, but that was before Consumer Reports reported a 60-0 mph stopping distance of 152 feet, nearly 20 feet longer than ours...

Except, of course, CR reported 133 feet. Same as they got. On the first stop

It was LATER stops (showing the ABS glitch) that got them to 152.


We caught you lying about this- remember?

YOU claimed ALL of CRs stops were excessively long. That's a lie.

it's factually untrue.

I directly quoted CR in my last post showing you lied about it.


here we go again-

and it wasn't just that their tested stopping distances got longer and longer. It was poor calibration of the ABS system that caused both an initial longer stopping distance.

In our testing of the Model 3, the first stop we recorded was significantly shorter (around 130 feet, similar to Tesla’s findings)

Further- when they got the gltich fixed and retested- guess what they got as results?
Tesla Model 3 Gets CR Recommendation After Braking Update

In retesting after the software update was downloaded, the sedan stopped in 133 feet from 60 mph

133 feet.

exactly the same distance as the first stop with the bad software.


So- once again- the actual facts exactly confirm what I told you, and caught you lying about


Don't imagine we should wait around for an apology though huh?

Interesting that you claim I have difficulty reading, but it appears you forget about the information in your (recently) Googled links

...and caught lying again

You can find posts from me citing that specific "how ABS works" paper going back years including on this very forum.

: "a quick calculation, the ABS determines that in order to have slowed 1 MPH in a 50ms period the wheels must be decelerating at a rate of 0.91g's. Because you are driving a sports car, the engineer who calibrated the system 'taught' the ABS that your car is capable of decelerating at this rate, so the ABS continues to hang back and watch the event from the spectator's booth. No problem so far."

Weren't you saying something earlier about when Edmunds swapped on the 19" wheel and tire combo, and the car stopped shorter? Which value (rather, envelope) does the engineer calibrate to then? The stickier 19" tire or the 18"? Optimizing for one results in sub-optimal effects for the other, because as you've stated, the vehicle doesn't know what tire is on the car.

But, I thought it was all about the tires?

Your minimum stopping distance is.

That's not at all what the bit you quote is discussing though.

Why wouldn't they come up?

I mean- I literally tell you that in the paragraph you're quoting.

There's that not actually reading what you're replying to thing again!

Both matter?! But, I thought it was only the tires as you've so fervently and verbosely explained

I mean- if you're gonna keep both not reading most of what's actually posted, then lie about what you imagine it said- I guess it's your time to waste

With the exception that rotors can't make the tires stickier (just like tires can't make the rotors bigger), 100% incorrect.

Rotors make your tires stickier?

Are you high?



They won't change the tire, but they will change how you use that tire under braking. Why, because tire friction isn't static? This is the part that you seem to have trouble understanding and way out of your element on. Something that a few Internet articles can't explain. Your formula that you like to use, uses an average tire u under the deceleration event for the entire vehicle - kinematic equations from high school physics. When you direct your attention to the tire itself, the resultant force that the tire produces back on the suspension assembly (as a result of the brakes operating) is the combination of the normal force on that tire (which changes from static with weight transfer and road irregularities) and the available u (which also changes with normal force and the slip ratio of that tire). Do you know what slip ratio is? You seem to know it all, so please educate us on how maximize longitudinal tire friction using slip ratio data and load sensitivity of the tire.

If this was all figured out, then why would researchers continue to work on ABS control dynamics to improve control and potentially stopping distances? Like these:
Anti-Lock Braking System Using Predictive Control and On-Line Tire/Road Characteristics Estimation - ScienceDirect

So from that link-

the longitudinal deceleration is considered to be directly and exclusively linked with the tire/road friction force. Furthermore, the brake level is often supposed to be equally distributed on the wheels. For other applications, as aircraft braking, these hypotheses are not appropriate

In other words they're saying the existing system is fine for cars- but they think there's a better brake-control methods for aircraft (for reasons gone into in further detail in the rest of the paper- eventually ending with landing simulations done on a Airbus A340.

Academically interesting- but not super relevant.

An optimal control for a novel ABS based on vehicle dynamic load transfer effect for reducing stopping distance - IEEE Conference Publication

Title is certainly interesting- though full doc hidden behind a paywall.

I did find one graph apparently from that study (though again full thing requires login)- it shows no divergence in stopping distance for the first 1/3rd of the braking event, and by the end of it a difference of a few tenths of a meter

Well stop the presses on that one!



More relevantly though- maybe you forgot... the thread is about the P3D+ vs P3D-?

Where the different in braking systems is things like the rotors and pads and calipers.

And it says nothing whatsoever in that source about changing rotors or pads or calipers to reduce braking distance.

It doesn't suggest, at all that changing to bigger/better brake parts can reduce stopping distance.

it seems to suggest that more optimized ABS control can get better use of the tires max available friction against the road.

Because, after all, that's what stops the car

https://pdfs.semanticscholar.org/f0cc/abf56133806b19ca0ef692b196a92bb7eeea.pdf

Same deal

the actual friction force between tyre and road will oscillate around a ”maximum” point

They are trying to improve the ABS system to again keep things as near that maximum point as much as possible.

NOTHING in there suggests bigger rotors, or different pads, or bigger calipers, or stainless lines, or anything of the sort, will help you stop any shorter.

It is, again, all about the tire and road interface

You know- the thing that stops the car

Fuzzy Life-Extending Control of Anti-Lock Braking System - ScienceDirect

...did you not read your own source again?

Because guess what that ones actually about?

The key idea of the system proposed in this paper is that a significant improving in service life can be achieved, especially during transient operations, by a small reduction in the dynamic performance of the system

He's suggesting he found a way to make ABS performance WORSE- but the parts will last a lot longer!

So also incredibly not relevant- but kinda funny!

So... 4 sources.



0 of which support the idea that the P3D+ brakes would stop you any shorter than the P3D- brakes on the same tires and same external conditions (road surface in particular).

Several of which reinforce it's the tire/road interface that actually matters and actually stops the car though... like you keep being told and keep getting confused about.


You're 0 for HOW MANY now?

DING DING DING! By golly, I think we're starting to understand.

Are we? Because that's literally what I've been explaining to you since the very beginning- and you keep trying to disagree with.

I mean- if you're finally admitting I was right in the first place, kudos... but I rate that as unlikely

Sure, to the untrained person, they're likely to not gain anything from brake upgrades for cold stopping distances

Also to trained ones.

Since you've been quoted by major brake OEMs, professional braking system designers, and folks like Car and Driver all confirming the same thing.

The car won't stop any shorter in a normal panic stop by upgrading any of those things on a properly working factory system.

But, to someone who knows what they're doing, they could probably find some items in the braking system (and suspension) to better optimize the tires that came on the vehicle for even cold max decel events.

And yet you continue to present 0 evidence or sources for this claim- a claim directly contradicted by a slew of sources given to you.

And the sources you DID provide all ignore the idea of upgrading any of those parts and instead focus on tuning ABS to better maximize the TIRE TO ROAD FRICTION.

Ya know- the thing that actually stops the car

. But, more time on here = less time in other threads )

I admire the consistency with which you manage to be wrong about everything

 

[Knightshade]

Paddy,

By all means if you can cite me any sources showing objective testing demonstrating reduced stopping distance of a modern ABS equipped car by changing things like the shocks or springs- please do.

Even companies that sell those things for a living don't appear to claim they help with that though- which seems like a pretty big thing they'd crow about if it were demonstrably true.

(that said- much like other cases already discussed- FAILING suspension parts can make such distances LONGER... and some suspension parts sellers DO crow about that... but I've never seen one claim their "upgrade" to a working non-worn-out OEM part would SHORTEN your stopping)


Ditto brake parts- where instead both Brembo and Stoptech explicitly confirm what I'm telling you- brake upgrades won't stop you any shorter at all in a normal street panic stop. Their kits are useful for things like fade resistance in heavy repeated high speed stops, allowing you to stop in the same distance over more repeated stops without needing to let things cool down. Seems like if BBKs reliably and objectively could stop you shorter, Brembo would be ALL OVER advertising that- even trying to push BBKs on moms in minivans telling them to THINK OF THE CHILDREN.

 

[Paddy3101]

Paddy,

By all means if you can cite me any sources showing objective testing demonstrating reduced stopping distance of a modern ABS equipped car by changing things like the shocks or springs- please do.

Even companies that sell those things for a living don't appear to claim they help with that though- which seems like a pretty big thing they'd crow about if it were demonstrably true.

(that said- much like other cases already discussed- FAILING suspension parts can make such distances LONGER... and some suspension parts sellers DO crow about that... but I've never seen one claim their "upgrade" to a working non-worn-out OEM part would SHORTEN your stopping)


Ditto brake parts- where instead both Brembo and Stoptech explicitly confirm what I'm telling you- brake upgrades won't stop you any shorter at all in a normal street panic stop. Their kits are useful for things like fade resistance in heavy repeated high speed stops, allowing you to stop in the same distance over more repeated stops without needing to let things cool down. Seems like if BBKs reliably and objectively could stop you shorter, Brembo would be ALL OVER advertising that- even trying to push BBKs on moms in minivans telling them to THINK OF THE CHILDREN.

This isn't an academic research paper, plenty of research out there if you want to look. Lookup threshold braking for example.

If you are talking about 'Panic' braking, then you are already NOT breaking as fast as the car could brake. The car can brake is a significantly shorter distance if you don't PANIC stop, relying on ABS to control the skid. Threashold, braking, (before a skid is initiated) will stop the car more quickly, and the tires will provide significantly MORE traction, than in a panic stop.

You are also dis-regarding the transition period BEFORE you reach maximum effectiveness. Changing brakes and suspension can reduce the time before reaching maximum braking effectiveness, by reducing the time taken for the weight transfer to stabilize, and hence reduce stopping distance.

The key here, is that the 'WHOLE SYSTEM' needs to be optimized to improve it, changing one aspect, affects others. This isn't a 'stable-state' system, the physics equations will only give you the 'bounds' or limits, not the actual results.

You can't provide more traction than the tires can provide, (Absolutely Correct - but not a complete picture). You can cause the tires to provide more (or less) traction, by optimizing their contact with the road, and the weight applied to them, and how that is dynamically changing, over time.

OEM systems are pretty good, over a wide range of conditions. Narrow the range of conditions, and limitations that the system is being applied to, and it can perform better in those narrower conditions.

e.g. If you don't mind stiffer suspension, and a bit of braking noise, you can speed up the weight transfer, and 'bite' of the braking system (pad material, brake hoses, caliper piston ratio/design) to get you to maximum braking effectiveness quicker, which WILL reduce stopping distance, on a nice, smooth road. (Probably worse on a rough, gravel track when it's snowing though)

 

[Knightshade]

This isn't an academic research paper, plenty of research out there if you want to look.

You made the claim.

Support it.

If you are talking about 'Panic' braking, then you are already NOT breaking as fast as the car could brake. The car can brake is a significantly shorter distance if you don't PANIC stop, relying on ABS to control the skid.

You seem confused about the topic.

Stopping distance, as measured professionally, is generally measured as a single panic stop- generally from about 60 mph (in non-metric places anyway) by putting your foot to the floor and measuring how long before the car has stopped.

That's also how 99.9% of drivers stop a car in an emergency on the street/highway too.

(versus fade resistance, where you might do that, often from higher speeds, back to back to back and measure when and by how much the distance gets longer (never shorter) the more you heat the system- a test where unlike stopping distance, brake upgrades can actually help)


The original discussion was about the fact that upgraded brakes (or suspension parts) can not shorten that distance.

The only thing that can is stickier tires. Because that's what actually stops the car.


Everyone (far as I can tell) agreed there were MANY advantages on a racetrack to various brake (or suspension) upgrades- though again none will get you a shorter normal single street stop

Changing brakes and suspension can reduce the time before reaching maximum braking effectiveness, by reducing the time taken for the weight transfer to stabilize, and hence reduce stopping distance.

Then it's weird the folks who actually design, or sell, these systems and parts don't generally claim such a thing.

In fact several (Brembo and Stoptech having already been quoted) say you're wrong.

But if you think you're not, I note you still haven't provided any evidence of it.

e.g. If you don't mind stiffer suspension, and a bit of braking noise, you can speed up the weight transfer, and 'bite' of the braking system (pad material, brake hoses, caliper piston ratio/design) to get you to maximum braking effectiveness quicker, which WILL reduce stopping distance, on a nice, smooth road.

 

[Mash]

 

[kev1n]

good. people should just buy the LR AWD if they dont want a Performance

 

[Paddy3101]

You made the claim.

Support it.




You seem confused about the topic.

Stopping distance, as measured professionally, is generally measured as a single panic stop- generally from about 60 mph (in non-metric places anyway) by putting your foot to the floor and measuring how long before the car has stopped.

That's also how 99.9% of drivers stop a car in an emergency on the street/highway too.

(versus fade resistance, where you might do that, often from higher speeds, back to back to back and measure when and by how much the distance gets longer (never shorter) the more you heat the system- a test where unlike stopping distance, brake upgrades can actually help)


The original discussion was about the fact that upgraded brakes (or suspension parts) can not shorten that distance.

The only thing that can is stickier tires. Because that's what actually stops the car.


Everyone (far as I can tell) agreed there were MANY advantages on a racetrack to various brake (or suspension) upgrades- though again none will get you a shorter normal single street stop




Then it's weird the folks who actually design, or sell, these systems and parts don't generally claim such a thing.

In fact several (Brembo and Stoptech having already been quoted) say you're wrong.

But if you think you're not, I note you still haven't provided any evidence of it.




View attachment 545044

Ok, how about AMG Mercedes driving school, they should know a thing or two about it.

Listen/Watch about threshold breaking, and transition time to full threshold braking.

Locking up/using ABS reduces braking force by 30percent.
Faster transition reduces stopping distances.

Faster reacting brakes/suspension reduces stopping distances.

 

[Bigtuna00]

This must be the car version of Godwin's Law...

 

[moridin2002]

This must be the car version of Godwin's Law...

I'm trying to see if we can get him/her to that point Is merely posting that link a self-fulfilling prophecy though?

 

[Knightshade]

Ok, how about AMG Mercedes driving school, they should know a thing or two about it.

Listen/Watch about threshold breaking, and transition time to full threshold braking.

Locking up/using ABS reduces braking force by 30percent.
Faster transition reduces stopping distances.

Faster reacting brakes/suspension reduces stopping distances.

So first, of course, they make clear what they're showing is trained drivers doing things you shouldn't do on public roads.

So the actual topic- normal emergency braking on public roads- is already out the window.


Second- they're specifically talking about braking during high speed turns on a track to take turns optimally as possible while coming out of it in the best shape- which again is about as far as you can get from a panic stop on legal roads from legal speeds.


Third-Even worse- he explicitly contradicts you in the video.

Locking up/using ABS reduces braking force by 30percent

What he actually says is LOCKING UP THE WHEELS does that. Which he THEN explains is what ABS avoids happening

ABS, in contrast, he says- specifically starting at 1:18, where he explains threshold braking, "that's what ABS does...so that you can stop in the shortest possible distance"

(and of course as we know- what IS the shortest possible distance determined by?

The tires.


And lastly- At no point in the entire video do they claim upgrading your brakes (or suspension) reduces stopping distance.


So as a source to support any of your claims or of any relevance to the topic I award you zero points.

Your own source directly contradicting your quote of it would actually take away points- if you'd ever earned any



I'd suggest you quit while you're behind- but folks fundamentally wrong about this stuff never do and just keep doubling down with more sources they didn't actually understand don't agree with em.

 

[dimachaerus]

Can we get a mod to lock this thread or change the title to "deep dive on brakes"? The last 3 pages have been about brakes and not about the performance checkbox being removed.

 

[Dolemite]

 

[MagnusMako]

Honestly, please let's just stop with the brake argument. Move that somewhere else and let's stick to the topic at hand.

 

[moridin2002]

Honestly, please let's just stop with the brake argument. Move that somewhere else and let's stick to the topic at hand.

While I want to agree with you, the longer we tie up the usual party here, the freer other threads become.

 

[Knightshade]

While I want to agree with you, the longer we tie up the usual party here, the freer other threads become.

I mean- I guess maybe you can only do one thing at a time? Not everyone has your limitations though