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Need help INTERPRETING these test results police cruiser SAE J866a Chase Test



 
 
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  #21  
Old January 14th 18, 04:04 PM posted to rec.autos.tech
[email protected]
external usenet poster
 
Posts: 128
Default Need help INTERPRETING these test results police cruiser SAEJ866a Chase Test

On Saturday, January 13, 2018 at 4:12:42 PM UTC-6, The Real Bev wrote:
> On 01/13/2018 12:39 PM, Mary-Jane Rottencrotch wrote:
> > On 2018-01-11 12:09, Mad Roger wrote:
> >>
> >> It seems there *must* be other *major* factors in braking performance,
> >> other than the friction rating of the pads themselves.
> >>
> >> That's a hard logical pill to swallow, for me, which is why I asked here,
> >> hoping the s.e.r folks can enlighten us as to why.

> >
> > Whats the stupid fixation with the coefficient of friction anyway?
> >
> > As any fule kno, friction is notionally independent of contact area, and
> > force due to friction is determined by the coefficient of friction *and
> > the applied force* so if you want more frictional force, you just need
> > to press the pedal harder, or have more servo assistance.

>
> Yu kleerly paid atenshun to Sigismund the Mad Maths Master! Matron
> would be pleesed.
>
> --
> Cheers, Bev
> "What fresh hell is this?" -- Dorothy Parker


Eau, what fresh towel is this?
Ads
  #22  
Old January 14th 18, 05:37 PM posted to alt.home.repair,sci.electronics.repair,rec.autos.tech
Mad Roger
external usenet poster
 
Posts: 61
Default Need help INTERPRETING these test results police cruiser SAE J866a Chase Test

On Sun, 14 Jan 2018 01:30:23 -0800 (PST),
wrote:

>> I'm not sure how to extrapolate that information to stopping distances.

>
> I would have thought that as long as the driver & brake servo can
> apply enough force it would make no difference at all to stopping
> distances.


Thanks for that observation as I'm trying to derive as much real-world
benefit from the police cruiser report as is possible given Clare's astute
observations about EE and FF pads faring differently, but not because of
their coefficient of friction.

There were 3 police tests over the decade, where only the penultimate test
aimed for uniform pedal pressure.
1.
https://www.justnet.org/pdf/BRAKEPAD.PDF
2. https://www.justnet.org/pdf/EvaluationBrakePads2000.pdf
3. https://www.justnet.org/pdf/Copy-of-...port-Draft.pdf


The middle test is the one that aimed for a given pedal pressu
a. 45-to-15mph at 10ft/s/s (approximately ~10 foot pounds +- a few)
b. 70-to-30mph at 22ft/s/s (approximately ~20 foot pounds +- a few)
c. 90-to-0mph at 22ft/s/s (approximately ~30 foot pounds +- a few)

Fundamentally, they said pedal pressure is, effectively, what a human does
all day every day - hence pedal pressure is, arguably, more important in a
well-used "cruising" vehicle that doesn't do panic stops consistently.

A targeted deceleration rate where pedal force is proportional to pad temp.

The other two studies were different.
1. Mostly stopping distance
2. Mostly pedal pressure
3. Mostly driver perception

In the end, the DOT edge code (AMECA edge code) is only slightly useful to
a consumer, I think. I wish it were more useful, but I've gleaned out of it
what I can, and that's the best any of us can hope to do.

I was hoping to get more insight from the scientific and mechanical folks
here.


  #23  
Old January 14th 18, 05:51 PM posted to alt.home.repair,sci.electronics.repair,rec.autos.tech
Fox's Mercantile
external usenet poster
 
Posts: 12
Default Need help INTERPRETING these test results police cruiser SAEJ866a Chase Test

On 1/14/18 10:37 AM, Mad Roger wrote:
> I was hoping to get more insight from the scientific and
> mechanical folks here.


Ain't gonna happen.
The people what know how this **** works aren't going to
waste their time arguing with your preconceived misconceptions.


--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com
  #24  
Old January 14th 18, 07:20 PM posted to alt.home.repair,sci.electronics.repair,rec.autos.tech
Mad Roger
external usenet poster
 
Posts: 61
Default Need help INTERPRETING these test results police cruiser SAE J866a Chase Test

On Sun, 14 Jan 2018 01:27:58 -0800 (PST),
wrote:

>> The real question who in the hell ****ing cares??

>
> I didn't, until I found the brake pads fitted by a quick nationwide chain a year earlier were totally disintegrating.
>
> Funny thing is you can get the same brake pads at a scrapyard for a fraction the price, but no-one wants to.


It's a valid question of who cares about choosing the proper brake pads.

Bear in mind that the Toyota FF pads are $157 a set at the local
dealership, while at a local parts store, I can get FF pads for $20 a set.

C = Up to 0.15u
E = 0.15u to 0.25u
E = 0.25u to 0.35u
F = 0.35u to 0.45u
G = 0.45u to 0.55u
H = 0.55u to 0.65u
Z = Unclassified

That's a huge difference in price, for material that has the same friction
coefficient, if not quality, don't you think?

So it behooves intelligent people to figure out, scientifically, whether
there is a way to tell what's *different* about those pads.

Everyone understands a number line, but there are non-linear issues here
which nobody here seems (so far) to understand such that they can tell us
how to properly compare the two brake pads based on the information a
consumer would have.

In the end, I don't see any indication whatsoever that anyone here knows
how to properly compare the performance of those $157 and $20 brake pads
and shoes in order to make an intelligent buying decision.

That's kind of a sad revelation for this newsgroup, don't you think?
  #25  
Old January 14th 18, 08:46 PM posted to alt.home.repair,sci.electronics.repair,rec.autos.tech
Clare Snyder
external usenet poster
 
Posts: 72
Default Need help INTERPRETING these test results police cruiser SAE J866a Chase Test

On Sun, 14 Jan 2018 18:20:33 -0000 (UTC), Mad Roger
> wrote:

> On Sun, 14 Jan 2018 01:27:58 -0800 (PST),
> wrote:
>
>>> The real question who in the hell ****ing cares??

>>
>> I didn't, until I found the brake pads fitted by a quick nationwide chain a year earlier were totally disintegrating.
>>
>> Funny thing is you can get the same brake pads at a scrapyard for a fraction the price, but no-one wants to.

>
>It's a valid question of who cares about choosing the proper brake pads.
>
>Bear in mind that the Toyota FF pads are $157 a set at the local
>dealership, while at a local parts store, I can get FF pads for $20 a set.
>
>C = Up to 0.15u
>E = 0.15u to 0.25u
>E = 0.25u to 0.35u
>F = 0.35u to 0.45u
>G = 0.45u to 0.55u
>H = 0.55u to 0.65u
>Z = Unclassified
>
>That's a huge difference in price, for material that has the same friction
>coefficient, if not quality, don't you think?
>
>So it behooves intelligent people to figure out, scientifically, whether
>there is a way to tell what's *different* about those pads.
>
>Everyone understands a number line, but there are non-linear issues here
>which nobody here seems (so far) to understand such that they can tell us
>how to properly compare the two brake pads based on the information a
>consumer would have.
>
>In the end, I don't see any indication whatsoever that anyone here knows
>how to properly compare the performance of those $157 and $20 brake pads
>and shoes in order to make an intelligent buying decision.
>
>That's kind of a sad revelation for this newsgroup, don't you think?



Not at all. Even a "brake engineer" would not be able to tell ypou
how to tell the good fromthe bad (or less good - don't knowthere is
any "bad"brakes on the market - even a lot of the "counterfeit" stuff
will stop the car). The "brake engineer" would likely beable to tell
you which of "his" product is better - but not necessarily if his was
betteror worse than another brand.

Back when I was a Toyota tech and service manager there were at least
2 different formulationsof brake pad that fit numerous Toyota vehicles
of the time - one was used up to a particular production date, and
another after. Both were available as replacement parts, and I always
used the one, regardless of vehicle production date, because it
stopped better and I could install the second and third set without
having to replace rotors. It was a difference between the metal used
in the "semi metallic" lining. One was magnetic - the other had brass
in it. The brass stopped better and didn't cause pitting of the
rotors. The pads didn't last as long, but virtually nobody ever
actually wore out the "magnetic" ones before the rotors needed
replacing, so the pad life, in and of itself, was a total non-issue.
IIRC the brass was the early pad and the iron was the
replacement/update.

The same situation rose years back on, I believe, FORD brake shoes
where the linings would deteriorate and fall apart before the half
wear point. They went from rivetted to bonded, and then the glue
started letting go, and the entire lining would free-wheel between the
shoes and the drum. It was a real bugger if that happened only on one
front wheel. It would have a MONSTEWROUS pull one time, then brake
fine the next - and you NEVER knew when it was going to pull - or
which way - because sometimes the loose material would grab, sometimes
it would hold properly, andothertimes it would do virtually nothing -
- -

Brake materials are a fine line between a science and a "black art"
  #26  
Old January 15th 18, 12:11 AM posted to alt.home.repair,sci.electronics.repair,rec.autos.tech
Mad Roger
external usenet poster
 
Posts: 61
Default Need help INTERPRETING these test results police cruiser SAE J866a Chase Test

On Sun, 14 Jan 2018 14:46:53 -0500,
Clare Snyder wrote:

>>In the end, I don't see any indication whatsoever that anyone here knows
>>how to properly compare the performance of those $157 and $20 brake pads
>>and shoes in order to make an intelligent buying decision.
>>
>>That's kind of a sad revelation for this newsgroup, don't you think?

>
> Not at all. Even a "brake engineer" would not be able to tell ypou
> how to tell the good fromthe bad (or less good - don't knowthere is
> any "bad"brakes on the market - even a lot of the "counterfeit" stuff
> will stop the car).


Hi Clare,
You're actually the *only* one on any of these three newsgroups who knew
the bottom line from the start, which is that we're ****ed when we try to
compare a $157 brake pad with a $20 brake pad.

Everyone loves a number line, which is why people buy batteries by warranty
or why they say the stupid line that "you get what you pay for" when we all
know that a $300 set of speakers at Toyota gets you a crappy speaker
compared to a $50 set at Crutchfields.

So you can never tell by price. You can only tell by quality.
And there's no way to *compare* quality, it seems.

You knew that. Which is why you stick to name brands. Which is fine, as
name brands is just another way of saying you buy by a number line, where
the number line only has parts on the right and left of zero.

Brands to the right of zero you'd buy (e.g., Napa or Wagner) and brands to
the left you wouldn't buy.

But that sucks too as a determinant although at least with the DOT Edge
Code, we can tell, for sure, which company made the friction material (so
we could tell that an Axxis pad is the same as a PBR which is the same as a
Metal Masters pad, for example).

> The "brake engineer" would likely beable to tell
> you which of "his" product is better - but not necessarily if his was
> betteror worse than another brand.


Yes. That's what the AMECA engineer basically said. He even said, many
times, that the brake engineer might not even know himself, unless he
himself submitted the pad material for testing.

So, basically EVERYONE is buying brake pads completely blind.

If that's not sad to you, it is to me.

> Back when I was a Toyota tech and service manager there were at least
> 2 different formulationsof brake pad that fit numerous Toyota vehicles
> of the time - one was used up to a particular production date, and
> another after. Both were available as replacement parts, and I always
> used the one, regardless of vehicle production date, because it
> stopped better and I could install the second and third set without
> having to replace rotors. It was a difference between the metal used
> in the "semi metallic" lining. One was magnetic - the other had brass
> in it.


If you have the DOT Edge Code, we could tell at least who made each
friction material, and whether they're on other pads, and whether they
truly were the same or not, and what the friction coefficients were.

But that's about it for what we could tell about the two pads from just
having them both in our hands.

That's sad.

> The brass stopped better and didn't cause pitting of the
> rotors. The pads didn't last as long, but virtually nobody ever
> actually wore out the "magnetic" ones before the rotors needed
> replacing, so the pad life, in and of itself, was a total non-issue.
> IIRC the brass was the early pad and the iron was the
> replacement/update.


I don't even look at the marketing bull**** because one spec of dust and
they can call it ceramic. There's no law or rules. They can put a spec of
iron and then call it semi metallic.

The only laws are they can't put asbestos in it.

The rest is marketing bull****. We've been there, so let's not go there
again.

We're essentially choosing brake pads almost completely blind.
And that's sad.

> The same situation rose years back on, I believe, FORD brake shoes
> where the linings would deteriorate and fall apart before the half
> wear point. They went from rivetted to bonded, and then the glue
> started letting go, and the entire lining would free-wheel between the
> shoes and the drum.


Yes. I'm not covering defects in workmanship or design of the backing.
I'm just covering the friction material here, because friction is the
fundamental thing a brake pad does.

I know all about the issues that we will never be able to compare pads with
such as longevity of the pads and rotors, fitment, noise, dusting, etc.

> Brake materials are a fine line between a science and a "black art"


I agree that for the *formulator*, it's likely halfway between science and
a black art, but for the poor consumer, it's complete marketing bull****.

Nobody, it appears, actually knows anything about buying brake pads when
they have two pads they've never seen before in their hands.

You have the EXPERIENCE to pick a pad, but even if I shoved two pads that
you have never seen before (such as two I'm going to need to compare), you
can't compare them either (unless you know the brand).

Even then, you harp on the conterfeits, so unless you know a telltale sign,
you can't tell from the brand either, especially when buying online.

SO it's just sad, sad, sad, that we're all utterly blind when it comes to
comparing brake pads. I think that's very depressing. We're at the mercy of
marketing bull****ters and idiots who do brake pad reviews on amazon that
make no sense and aren't for the same car and compare things like worn old
pads against brand new pads, and the butt dyno takes over from there.

All those reviews are basically worthless.
All the marketing bull**** is basically worthless.

The one dream I had was that this AMECA Edge Code could tell me a lot, and
it does tell me three things, but that's it.

Sigh. It's just sad.

I do thank you for your help, as you're the only one, I think, who knew
what he was talking about from the start. I had to learn it. You already
knew it.
  #27  
Old January 15th 18, 12:27 AM posted to alt.home.repair,sci.electronics.repair,rec.autos.tech
AMuzi
external usenet poster
 
Posts: 488
Default Need help INTERPRETING these test results police cruiser SAEJ866a Chase Test

On 1/14/2018 5:11 PM, Mad Roger wrote:
> On Sun, 14 Jan 2018 14:46:53 -0500,
> Clare Snyder wrote:
>
>>> In the end, I don't see any indication whatsoever that anyone here knows
>>> how to properly compare the performance of those $157 and $20 brake pads
>>> and shoes in order to make an intelligent buying decision.
>>>
>>> That's kind of a sad revelation for this newsgroup, don't you think?

>>
>> Not at all. Even a "brake engineer" would not be able to tell ypou
>> how to tell the good fromthe bad (or less good - don't knowthere is
>> any "bad"brakes on the market - even a lot of the "counterfeit" stuff
>> will stop the car).

>
> Hi Clare,
> You're actually the *only* one on any of these three newsgroups who knew
> the bottom line from the start, which is that we're ****ed when we try to
> compare a $157 brake pad with a $20 brake pad.
>
> Everyone loves a number line, which is why people buy batteries by warranty
> or why they say the stupid line that "you get what you pay for" when we all
> know that a $300 set of speakers at Toyota gets you a crappy speaker
> compared to a $50 set at Crutchfields.
>
> So you can never tell by price. You can only tell by quality.
> And there's no way to *compare* quality, it seems.
>
> You knew that. Which is why you stick to name brands. Which is fine, as
> name brands is just another way of saying you buy by a number line, where
> the number line only has parts on the right and left of zero.
>
> Brands to the right of zero you'd buy (e.g., Napa or Wagner) and brands to
> the left you wouldn't buy.
>
> But that sucks too as a determinant although at least with the DOT Edge
> Code, we can tell, for sure, which company made the friction material (so
> we could tell that an Axxis pad is the same as a PBR which is the same as a
> Metal Masters pad, for example).
>
>> The "brake engineer" would likely beable to tell
>> you which of "his" product is better - but not necessarily if his was
>> betteror worse than another brand.

>
> Yes. That's what the AMECA engineer basically said. He even said, many
> times, that the brake engineer might not even know himself, unless he
> himself submitted the pad material for testing.
>
> So, basically EVERYONE is buying brake pads completely blind.
>
> If that's not sad to you, it is to me.
>
>> Back when I was a Toyota tech and service manager there were at least
>> 2 different formulationsof brake pad that fit numerous Toyota vehicles
>> of the time - one was used up to a particular production date, and
>> another after. Both were available as replacement parts, and I always
>> used the one, regardless of vehicle production date, because it
>> stopped better and I could install the second and third set without
>> having to replace rotors. It was a difference between the metal used
>> in the "semi metallic" lining. One was magnetic - the other had brass
>> in it.

>
> If you have the DOT Edge Code, we could tell at least who made each
> friction material, and whether they're on other pads, and whether they
> truly were the same or not, and what the friction coefficients were.
>
> But that's about it for what we could tell about the two pads from just
> having them both in our hands.
>
> That's sad.
>
>> The brass stopped better and didn't cause pitting of the
>> rotors. The pads didn't last as long, but virtually nobody ever
>> actually wore out the "magnetic" ones before the rotors needed
>> replacing, so the pad life, in and of itself, was a total non-issue.
>> IIRC the brass was the early pad and the iron was the
>> replacement/update.

>
> I don't even look at the marketing bull**** because one spec of dust and
> they can call it ceramic. There's no law or rules. They can put a spec of
> iron and then call it semi metallic.
>
> The only laws are they can't put asbestos in it.
>
> The rest is marketing bull****. We've been there, so let's not go there
> again.
>
> We're essentially choosing brake pads almost completely blind.
> And that's sad.
>
>> The same situation rose years back on, I believe, FORD brake shoes
>> where the linings would deteriorate and fall apart before the half
>> wear point. They went from rivetted to bonded, and then the glue
>> started letting go, and the entire lining would free-wheel between the
>> shoes and the drum.

>
> Yes. I'm not covering defects in workmanship or design of the backing.
> I'm just covering the friction material here, because friction is the
> fundamental thing a brake pad does.
>
> I know all about the issues that we will never be able to compare pads with
> such as longevity of the pads and rotors, fitment, noise, dusting, etc.
>
>> Brake materials are a fine line between a science and a "black art"

>
> I agree that for the *formulator*, it's likely halfway between science and
> a black art, but for the poor consumer, it's complete marketing bull****.
>
> Nobody, it appears, actually knows anything about buying brake pads when
> they have two pads they've never seen before in their hands.
>
> You have the EXPERIENCE to pick a pad, but even if I shoved two pads that
> you have never seen before (such as two I'm going to need to compare), you
> can't compare them either (unless you know the brand).
>
> Even then, you harp on the conterfeits, so unless you know a telltale sign,
> you can't tell from the brand either, especially when buying online.
>
> SO it's just sad, sad, sad, that we're all utterly blind when it comes to
> comparing brake pads. I think that's very depressing. We're at the mercy of
> marketing bull****ters and idiots who do brake pad reviews on amazon that
> make no sense and aren't for the same car and compare things like worn old
> pads against brand new pads, and the butt dyno takes over from there.
>
> All those reviews are basically worthless.
> All the marketing bull**** is basically worthless.
>
> The one dream I had was that this AMECA Edge Code could tell me a lot, and
> it does tell me three things, but that's it.
>
> Sigh. It's just sad.
>
> I do thank you for your help, as you're the only one, I think, who knew
> what he was talking about from the start. I had to learn it. You already
> knew it.
>


And all that is different from buying a bag of white flour
to make cookies in what way exactly?

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971


  #28  
Old January 15th 18, 05:51 AM posted to alt.home.repair,sci.electronics.repair,rec.autos.tech
Clare Snyder
external usenet poster
 
Posts: 72
Default Need help INTERPRETING these test results police cruiser SAE J866a Chase Test

On Sun, 14 Jan 2018 23:11:16 -0000 (UTC), Mad Roger
> wrote:

> On Sun, 14 Jan 2018 14:46:53 -0500,
> Clare Snyder wrote:
>
>>>In the end, I don't see any indication whatsoever that anyone here knows
>>>how to properly compare the performance of those $157 and $20 brake pads
>>>and shoes in order to make an intelligent buying decision.
>>>
>>>That's kind of a sad revelation for this newsgroup, don't you think?

>>
>> Not at all. Even a "brake engineer" would not be able to tell ypou
>> how to tell the good fromthe bad (or less good - don't knowthere is
>> any "bad"brakes on the market - even a lot of the "counterfeit" stuff
>> will stop the car).

>
>Hi Clare,
>You're actually the *only* one on any of these three newsgroups who knew
>the bottom line from the start, which is that we're ****ed when we try to
>compare a $157 brake pad with a $20 brake pad.
>
>Everyone loves a number line, which is why people buy batteries by warranty
>or why they say the stupid line that "you get what you pay for" when we all
>know that a $300 set of speakers at Toyota gets you a crappy speaker
>compared to a $50 set at Crutchfields.
>
>So you can never tell by price. You can only tell by quality.
>And there's no way to *compare* quality, it seems.
>
>You knew that. Which is why you stick to name brands. Which is fine, as
>name brands is just another way of saying you buy by a number line, where
>the number line only has parts on the right and left of zero.
>
>Brands to the right of zero you'd buy (e.g., Napa or Wagner) and brands to
>the left you wouldn't buy.
>
>But that sucks too as a determinant although at least with the DOT Edge
>Code, we can tell, for sure, which company made the friction material (so
>we could tell that an Axxis pad is the same as a PBR which is the same as a
>Metal Masters pad, for example).
>
>> The "brake engineer" would likely beable to tell
>> you which of "his" product is better - but not necessarily if his was
>> betteror worse than another brand.

>
>Yes. That's what the AMECA engineer basically said. He even said, many
>times, that the brake engineer might not even know himself, unless he
>himself submitted the pad material for testing.
>
>So, basically EVERYONE is buying brake pads completely blind.
>
>If that's not sad to you, it is to me.
>
>> Back when I was a Toyota tech and service manager there were at least
>> 2 different formulationsof brake pad that fit numerous Toyota vehicles
>> of the time - one was used up to a particular production date, and
>> another after. Both were available as replacement parts, and I always
>> used the one, regardless of vehicle production date, because it
>> stopped better and I could install the second and third set without
>> having to replace rotors. It was a difference between the metal used
>> in the "semi metallic" lining. One was magnetic - the other had brass
>> in it.

>
>If you have the DOT Edge Code, we could tell at least who made each
>friction material, and whether they're on other pads, and whether they
>truly were the same or not, and what the friction coefficients were.
>
>But that's about it for what we could tell about the two pads from just
>having them both in our hands.
>
>That's sad.
>
>> The brass stopped better and didn't cause pitting of the
>> rotors. The pads didn't last as long, but virtually nobody ever
>> actually wore out the "magnetic" ones before the rotors needed
>> replacing, so the pad life, in and of itself, was a total non-issue.
>> IIRC the brass was the early pad and the iron was the
>> replacement/update.

>
>I don't even look at the marketing bull**** because one spec of dust and
>they can call it ceramic. There's no law or rules. They can put a spec of
>iron and then call it semi metallic.
>
>The only laws are they can't put asbestos in it.
>
>The rest is marketing bull****. We've been there, so let's not go there
>again.
>
>We're essentially choosing brake pads almost completely blind.
>And that's sad.
>
>> The same situation rose years back on, I believe, FORD brake shoes
>> where the linings would deteriorate and fall apart before the half
>> wear point. They went from rivetted to bonded, and then the glue
>> started letting go, and the entire lining would free-wheel between the
>> shoes and the drum.

>
>Yes. I'm not covering defects in workmanship or design of the backing.
>I'm just covering the friction material here, because friction is the
>fundamental thing a brake pad does.
>



N o, the PRIMARY quality of a brake material that YOU need to worry
about is "performance"
That "performance" includes how well it stops hot and cold, brake
feel, pad life, and rotor life.

The coefficient of friction only affects ONE of those qualities - and
the gross difference between a good e and a poor g is NEGLIGIBLE .
(Both are essentially an F -)

AN OEM GUALITY brake part will be CLOSE to what was specified by the
manufacturer - may be marginally better or marginally worse - but they
will be close.

I talk to my jobber and ask what their warranty experience is with
different products. If they have noise complaints, or poor wear, on
one brand/model but not on another, I stay away from the one that has
problems.

Years ago I got and read the Service Station and Garage Management
magazine - which had articles about different products - written by
mechanics, not engineers and salemen, reporting both the Gems and the
Stinkers.

>I know all about the issues that we will never be able to compare pads with
>such as longevity of the pads and rotors, fitment, noise, dusting, etc.
>
>> Brake materials are a fine line between a science and a "black art"

>
>I agree that for the *formulator*, it's likely halfway between science and
>a black art, but for the poor consumer, it's complete marketing bull****.


Look for a certified label





New vehicles must meet federal performance standards—a minimum
stopping distance in a variety of situations under a specified pedal
effort. Many consumers assume all aftermarket replacement pads will
perform just as well or better than factory parts, but that's not
necessarily the case.

In an effort to improve the customer's comfort level—and also to avoid
future government regulations—brake manufacturers can test and verify
their products under two voluntary certification standards. Both are
designed to ensure that replacement brakes are as effective as
original equipment, and consumers should make sure that any pads being
installed on their vehicle are certified.

The first is an independent proprietary program developed by Greening
Testing Laboratories in Detroit called D3EA—which stands for Dual
Dynamometer Differential Effectiveness Analysis. This procedure tests
front and rear friction materials together on dual dynamometers, then
simulates vehicle weight and speed through a computer program to
measure braking effectiveness and balance for different applications.
D3EA was introduced in 1996, and among the first aftermarket companies
to achieve D3EA certification were ACDelco, NAPA, Raybestos, and
Satisfied.

The Brake Manufacturers Council (BMC) has a second certification
standard called BEEP, or Brake Effectiveness Evaluation Procedure.
BEEP testing is conducted on a single dynamometer, and the numbers are
washed through a computer program to compare brake performance with
federal standards for new vehicles. The BEEP approval seals appear on
packaging as manufacturers submit products for certification.

The D3EA tests are proprietary and more expensive, but they're also
completely independent and tougher to pass. Brake manufacturers have
contended that most consumers change only the front or rear brakes at
one time, so a concurrent dual test is unnecessary. But, according to
officials from Greening, NHTSA tests in the 1980s concluded there was
a significant reduction in braking performance when there was a
differential between front and rear replacement pads as compared with
original factory parts. That report provided some of the motivation
for the brake industry to begin seeking a certification standard
before the federal government issued regulations for replacement pads.
The obvious concern over BEEP testing is that the manufacturers
themselves oversaw the development of the certification standards.
While the program received input from the Society of Automotive
Engineers and actual certification is currently conducted at an
independent laboratory, BMC members can conduct similar tests on their
own single dynamometers and compute the numbers.

Consumers must remember that not all of an aftermarket manufacturer's
lineup gets certified, only pads designed for a specific vehicle that
passed the designated test. Also, since the D3EA tests are expensive,
manufacturers may test just the standard line for a particular
vehicle. One can assume then that any upgraded line from that same
manufacturer will meet the test standards. That's why heavy duty or
the new ceramic pads may not carry the seal. The best advice is to
look for manufacturers that aggressively test their standard line,
then move up in grade if you need more performance or seek other
advantages such as minimal wheel dust.


>
>Nobody, it appears, actually knows anything about buying brake pads when
>they have two pads they've never seen before in their hands.
>
>You have the EXPERIENCE to pick a pad, but even if I shoved two pads that
>you have never seen before (such as two I'm going to need to compare), you
>can't compare them either (unless you know the brand).
>
>Even then, you harp on the conterfeits, so unless you know a telltale sign,
>you can't tell from the brand either, especially when buying online.


Which is why I seldom buy stuff like that online - and if I do, I buy
from a vendor I KNOW is honest and reliable. (I'll sometimes order
parts from Napa Onlineand pick them ujp at my local napa store -
particularly if I find I need something on the weekend when the store
is not open and I want it for Monday)
>
>SO it's just sad, sad, sad, that we're all utterly blind when it comes to
>comparing brake pads. I think that's very depressing. We're at the mercy of
>marketing bull****ters and idiots who do brake pad reviews on amazon that
>make no sense and aren't for the same car and compare things like worn old
>pads against brand new pads, and the butt dyno takes over from there.


Then pay the extra and buy the Toyota parts - that way YOU KNOW what
you are buying. Sometimes peace of mind costs a few bucks.
>
>All those reviews are basically worthless.
>All the marketing bull**** is basically worthless.


Any review by DIY guys on places liike Amazon are generally worse
than useless.
>
>The one dream I had was that this AMECA Edge Code could tell me a lot, and
>it does tell me three things, but that's it.
>
>Sigh. It's just sad.


Buy D3EA certified parts and you stand a much higher than normal
chance of getting what you need.
>
>I do thank you for your help, as you're the only one, I think, who knew
>what he was talking about from the start. I had to learn it. You already
>knew it.

  #29  
Old January 15th 18, 03:19 PM posted to alt.home.repair,sci.electronics.repair,rec.autos.tech
Mad Roger
external usenet poster
 
Posts: 61
Default Need help INTERPRETING these test results police cruiser SAE J866a Chase Test

On Sun, 14 Jan 2018 17:58:04 -0800 (PST),
wrote:

> That's retail.


That's why I say those who say "you get what you pay for" are misguided
because a $157 pad "might" be just as good or bad as a $20 pad, where I can
prove this statement for the $300 20W Panasonic speakers in a Toyota since
I know the specs on the $50 speakers at Crutchfields.

Even at Crutchfields, you can get a good $50 speaker or a less-good $50
speaker, and the price is exactly the same.

So if someone tells me "you get what you pay for", they'll get the same
rant from me that everyone loves to pick products off a number line, but
the real number line is a bunch of specs, and not a simple price.

That's retail for you!

> And really the difference is greater, I once bought a set of 4 brake
> shoes for +AKM-1, that's under $2. They performed without any issue. Why?


I think price is not an indication of anything other than what the
marketing can make people pay. It's certainly not an indication of quality.

> No-one here wants to buy brake parts from scrapyards, even though
> they're the same parts you get in the shops.


I'm not sure what you mean by "scrapyards". To me, that means a junk yard,
which contains dead cars. I wouldn't buy brakes off a dead car for a
billion reasons which are obvious so I shouldn't need to state it.

What's the difference between my concept of a junkyard (which contains
entire cars that were thrown away) and your scrapyard?

Are you talking about *used* brake pads or *new* brake pads?

> if both do the job ok, $20 is the intelligent buying decision.


There is no other logical conclusion to be made, given the information we
have. Price is NOT the determinant of a good or bad brake pad.

The sad thing is that there is no determinant we can make that will hold
true other than there is no difference practically that you can do anything
about.

I'm NOT saying they are all the same. I'm saying we consumers can't tell by
having two of them in our hand or having two of them sold online.

> Moving to historic vehicles, how would I find out which friction rating
> of oak is?


Or rubber in bicycle brakes.
  #30  
Old January 15th 18, 03:19 PM posted to alt.home.repair,sci.electronics.repair,rec.autos.tech
Mad Roger
external usenet poster
 
Posts: 61
Default Need help INTERPRETING these test results police cruiser SAE J866a Chase Test

On Sun, 14 Jan 2018 23:51:59 -0500,
Clare Snyder wrote:

> the PRIMARY quality of a brake material that YOU need to worry
> about is "performance"
> That "performance" includes how well it stops hot and cold, brake
> feel, pad life, and rotor life.


Yes. But.
There's no way to tell that if you have two pads in your hands, and even
less of a way to tell if you're buying two pads online.

Remember, *all* the marketing is complete bull**** (refer back to
Axxis, PBR, and Metal Masters - three differently marketed and priced pads,
all exactly the same - and refer to the fact that there are no laws telling
them that a spec of dust isn't ceramic and that a spec of iron isn't
semimetallic.

The only law that I know of is that they can't call a non-asbestos pad that
if it contains asbestos.

Maybe someone here knows the laws, but that's my sad conclusion so far.

> The coefficient of friction only affects ONE of those qualities - and
> the gross difference between a good e and a poor g is NEGLIGIBLE .
> (Both are essentially an F -)


Yes. You have always been right on that. I don't disagree. I was hoping
beyond hope that there was a way for the consumer to tell pad A from pad B
when they are in the consumer's hands.

But it's not possible. Anyone who *thinks* he can tell, is fooling
himself. So every butt-dyno inspired "review" out there is complete
bull**** (and always was for a huge number of reasons).

Everything is bull****.
That's what's so sad.

The only thing we know, by looking at a pad, is who made it, what its
friction coefficient is, and whether or not some other pad is made by that
company and whether or not it's exactly the same friction material.

That's it. Everything else we "think" we know, is complete marketing
bull****.

> AN OEM GUALITY brake part will be CLOSE to what was specified by the
> manufacturer - may be marginally better or marginally worse - but they
> will be close.


Yes. You have always been right, but ... and this is a big butt!

1) If you get OE pads (from the dealer or pads with the exact same DOT Edge
Code), then you get the handling specified by the manufacturer (assuming
your vehicle is essentially the same, e.g., same size tires, same
suspension setup, etc.)

2) Otherwise, if you get somethign that some marketing guy "says" is "OEM
Quality", then you know almost nothing since you have to "ask" what the
**** "OEM Quality" means to the marketing bull****ter who is telling you
that.

So, if it's actually true that it's OEM Quality, then it's OEM Quality.

But what the **** does OEM Quality mean when we already know that the
second-order effects are almost as great as the first order effects here.

Does OEM Quality mean that the shoe has the same friction coefficient?
(Let's hope so - but it's *easy* to find an FF pad, so, it has to be more,
right?)

Does OEM Quality mean the shoe lasts as long?
Is as dustless?
Makes as much noise?
Has the same pedal force per deceleration value?
Outgasses the same?
Fades the same?

Who the **** knows the answer to that question?

The only Occam's Razor logical answer to that question is that OEM Quality
is bull**** unless you *trust* the guy who says it - and even then - he
doesn't know himself - so you'd have to trust the "scientist" who told him
to say that.

> I talk to my jobber and ask what their warranty experience is with
> different products. If they have noise complaints, or poor wear, on
> one brand/model but not on another, I stay away from the one that has
> problems.


Yes. I always defer to your greater experience. But I don't have "my
jobber". Heck, you are "my jobber", in effect.

So I understand that if I ask someone who has tons of experience, like you
do, then I can get closer, but even you can't tell me what the difference
is between the $20 pads and the $157 pads unless I dig up all the relevant
information about them, and even then, if your jobber isn't experienced
with them, then I'm back at starting point zero.

So your access to a jobber is great - but I don't have that access.

> Years ago I got and read the Service Station and Garage Management
> magazine - which had articles about different products - written by
> mechanics, not engineers and salemen, reporting both the Gems and the
> Stinkers.


Most people think that if you drop a big ball and a small ball, they'll
land at different times. Most people, I think, trust their feelings more
than they trust measurements.

That's why I don't trust butt dyno reports.

People feel their car goes faster if they put in $5/gallon fuel than if
they put in $2/gallon fuel, even if it doesn't. Their reviews are always
written to placate their own preconceived notions.

The *only* review I will trust is a blind review, where the driver doesn't
know anything about the pads, and where that driver didn't write the review
and didn't get paid for writing the review and who doesn't get
advertisement money either.

And that's almost zero reviews.
All those reviews in Car & Driver and Motortrend are bull****, IMHO.

I realize you're talking a *different* kind of mag, so maybe it's not a rag
like those are, but it's not something I'm going to read unless you know of
a brake comparison that is meaningful.

For example, I hear all the time someone claiming their Cooper tire is
better than my Dunlops or Hancook's, but without the manufacturer's
comprehensive tire test for *all* the tires, we have nothing to go by.

Same here.
Just having one test is useless.
The test has to cover all brake pads we have available to us.

And they just don't.

> Look for a certified label


As someone else said, the certified label is the receipt which has a zip
code, which proves that you bought the pads in the USA.

The only reliable conclusion we can make is that any pad legally sold in
the USA is about the same in performance as far as anyone can tell just by
looking at the pad.

Unless a scientific test has been run, they're all the same is the only
conclusion anyone can make, since any other conclusion (that they're
different) has to be based on bull****.

That's just sad.

> New vehicles must meet federal performance standards+AJc-a minimum
> stopping distance in a variety of situations under a specified pedal
> effort. Many consumers assume all aftermarket replacement pads will
> perform just as well or better than factory parts, but that's not
> necessarily the case.


I don't know that new vehicles must meet stopping distance standards but I
don't doubt you as you've been right all along.

However, any pad sold in the US has to also meet standards, and it seems
that any pad works, based on those standards.

I'm not saying that all pads are exactly alike. I definitely think they're
not. I'm just saying that all the information available to us saying they
are not alike, is based on bull**** that isn't backed up by any science
that is available to us.

As the Ameca engineer told me, the guy submitting the material is the only
guy who knows anything about them.

Nobody else does. And even that guy, the Ameca engineer kept telling me,
doesn't know anything about any other material.

> In an effort to improve the customer's comfort level+AJc-and also to avoid
> future government regulations+AJc-brake manufacturers can test and verify
> their products under two voluntary certification standards. Both are
> designed to ensure that replacement brakes are as effective as
> original equipment, and consumers should make sure that any pads being
> installed on their vehicle are certified.


Exactly. I have never been to a mechanic in my entire life, so I don't
really know what *other* people do, but I would *guess* that most people go
to a brake shop like Midas or America's Tire, or the local indy, and they
expect to get brake pads and shoes.

I doubt they ask much about what they got, but if I took a score of cars to
a score of brake shops, I wouldn't be surprised to get more than a dozen
different brands on the vehicle.

Only at the dealer would I expect a specific brand.

Is that a correct assumption? (I have zero experience with mechanics.)

I'll cover the rest separately.
I do appreciate your advice as you have been right all along.
You just happen to have more resources available to you than I have to me.
 




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