brake upgrades effect on ESC

Cars today have ABS, EBD, ESC, "active city stop", self-parking
and more.
I am wondering what happens if you upgrade the brakes (not with
OEM brakes). About 10 years ago, I put bigger rotors and master
cylinder on a car, and it did not upset the ABS, but that is
a lot simpler than the modern stuff. I am most worried about
ESC - I presume that is calibrated by computer simulations and
road tests with a mad stunt driver. Now suppose your brakes
have 30% more force than original- would the ESC get it wrong,
and you end up sideways in a ditch?

On 2013-08-26, > wrote:
> Cars today have ABS, EBD, ESC, "active city stop", self-parking
> and more.
> I am wondering what happens if you upgrade the brakes (not with
> OEM brakes). About 10 years ago, I put bigger rotors and master
> cylinder on a car, and it did not upset the ABS, but that is
> a lot simpler than the modern stuff. I am most worried about
> ESC - I presume that is calibrated by computer simulations and
> road tests with a mad stunt driver. Now suppose your brakes
> have 30% more force than original- would the ESC get it wrong,
> and you end up sideways in a ditch?

As far as I know there isn't any sort of force calibration table, the
computer simply looks at the wheel sensors and makes fine adjustments
until wheel sensors show everything is fine again. Some systems may
have accelerometers as well but the same principles are applied. The
steps are probably fine enough that nothing bad will happen with
upgraded brakes. These systems have to work with aftermarket pads and
people who neglect their cars thus in a FEMA I think it would come up to
avoid any scheme that used a force table but rather just use sensor data
and small increments.

Also, I've not heard of an issue in Mustang circles. Although I
don't know of anyone who changes the master cylinder* but rotors and
calipers are often changed. Ford even sells the brakes from the GT500
and brembo package cars for others to install and there is no need to
update software as far as I know.

*because there is no need as upgraded ford and aftermarket parts are
usually designed to work with the stock MC.

On 8/26/2013 5:57 AM, wrote:
> Cars today have ABS, EBD, ESC, "active city stop", self-parking
> and more.
> I am wondering what happens if you upgrade the brakes (not with
> OEM brakes). About 10 years ago, I put bigger rotors and master
> cylinder on a car, and it did not upset the ABS, but that is
> a lot simpler than the modern stuff. I am most worried about
> ESC - I presume that is calibrated by computer simulations and
> road tests with a mad stunt driver.

Pretty much right. The various parameters are indeed tested and tweaked
by real people wearing helmets and driving like a$$holes on closed test
tracks.

> Now suppose your brakes
> have 30% more force than original- would the ESC get it wrong,
> and you end up sideways in a ditch?

Probably not, but I in a car with ASC if you deviate from factory I
would make sure the parts are matched front-rear and side-side (a good
idea in any case.) The reason that I say that is that traction is
variable anyway, so the software is going to allow for variances between
dry asphalt, wet concrete, glare ice etc. But what you don't want to do
is put significantly more or less grippy brake pads on the front of the
car, say, and leave the stock pads on the rear. It might not cause a
problem - but then again it might. Likewise with tires, i'd prefer to
see all four tires match.

nate

On Mon, 26 Aug 2013 10:17:33 -0400, Nate Nagel >
wrote:

>On 8/26/2013 5:57 AM, wrote:
>> Cars today have ABS, EBD, ESC, "active city stop", self-parking
>> and more.
>> I am wondering what happens if you upgrade the brakes (not with
>> OEM brakes). About 10 years ago, I put bigger rotors and master
>> cylinder on a car, and it did not upset the ABS, but that is
>> a lot simpler than the modern stuff. I am most worried about
>> ESC - I presume that is calibrated by computer simulations and
>> road tests with a mad stunt driver.
>
>Pretty much right. The various parameters are indeed tested and tweaked
>by real people wearing helmets and driving like a$$holes on closed test
>tracks.
>
>> Now suppose your brakes
>> have 30% more force than original- would the ESC get it wrong,
>> and you end up sideways in a ditch?
>
>Probably not, but I in a car with ASC if you deviate from factory I
>would make sure the parts are matched front-rear and side-side (a good
>idea in any case.) The reason that I say that is that traction is
>variable anyway, so the software is going to allow for variances between
>dry asphalt, wet concrete, glare ice etc. But what you don't want to do
>is put significantly more or less grippy brake pads on the front of the
>car, say, and leave the stock pads on the rear. It might not cause a
>problem - but then again it might. Likewise with tires, i'd prefer to
>see all four tires match.
>
>nate

The whole point of the wheel sensors is to determine what the wheels
are doing. So I see no reason why you can't do pretty much anything
you want on and mix and match within reason with one possible
exception and that would be things that significantly change the
height of the center of gravity, like throwing those ghetto style 24
inch wheels on a car that came with 15 inch from the factory. Even
for that it's possible the car has "tiltometers" that would even
account for that kind of change.

On 8/26/2013 9:17 AM, Nate Nagel wrote:
> On 8/26/2013 5:57 AM, wrote:
>> Cars today have ABS, EBD, ESC, "active city stop", self-parking
>> and more.
>> I am wondering what happens if you upgrade the brakes (not with
>> OEM brakes). About 10 years ago, I put bigger rotors and master
>> cylinder on a car, and it did not upset the ABS, but that is
>> a lot simpler than the modern stuff. I am most worried about
>> ESC - I presume that is calibrated by computer simulations and
>> road tests with a mad stunt driver.
>
> Pretty much right. The various parameters are indeed tested and tweaked
> by real people wearing helmets and driving like a$$holes on closed test
> tracks.
>
>> Now suppose your brakes
>> have 30% more force than original- would the ESC get it wrong,
>> and you end up sideways in a ditch?
>
> Probably not, but I in a car with ASC if you deviate from factory I
> would make sure the parts are matched front-rear and side-side (a good
> idea in any case.) The reason that I say that is that traction is
> variable anyway, so the software is going to allow for variances between
> dry asphalt, wet concrete, glare ice etc. But what you don't want to do
> is put significantly more or less grippy brake pads on the front of the
> car, say, and leave the stock pads on the rear. It might not cause a
> problem - but then again it might. Likewise with tires, i'd prefer to
> see all four tires match.
>
> nate

Can vehicles with ASC be remotely hacked to handle like a dirt-tracker?
Would be funny to see luxury SUV's spinning like tops.

--
T0m $herm@n

On Tuesday, August 27, 2013 12:23:01 AM UTC+8, Ashton Crusher wrote:
> The whole point of the wheel sensors is to determine what the wheels
>
> are doing. So I see no reason why you can't do pretty much anything
>
> you want on and mix and match within reason with one possible
>
> exception and that would be things that significantly change the
>
> height of the center of gravity, like throwing those ghetto style 24
>
> inch wheels on a car that came with 15 inch from the factory. Even
>
> for that it's possible the car has "tiltometers" that would even
>
> account for that kind of change.

ESC is a step up from say traction control. It also monitors the yaw of
a vehicle and the steering wheel to predict if the car is about to skid
off the road. It needs to modulate each brake. I imagine if you have
2 wheels on the bitumen and 2 wheel on gravel verge, it would be pretty
clever to stay in control.

T0m $herman wrote:
>
>
> Can vehicles with ASC be remotely hacked to handle like a dirt-tracker?
> Would be funny to see luxury SUV's spinning like tops.
>

pull the fuse(s) for the appropriate module(s)...unless of course they
also feed the ECM....

GW

On 8/27/2013 2:58 PM, Geoff Welsh wrote:
> T0m $herman wrote:
>>
>>
>> Can vehicles with ASC be remotely hacked to handle like a dirt-tracker?
>> Would be funny to see luxury SUV's spinning like tops.
>>
>
> pull the fuse(s) for the appropriate module(s)...unless of course they
> also feed the ECM....
>
> GW

I was thinking along the lines of intentional destabilization, not just
turning off the system. Luxury SUV's bring out the misanthrope in me.

--
T0m $herm@n

On 08/27/2013 12:58 PM, Geoff Welsh wrote:
> T0m $herman wrote:
>>
>>
>> Can vehicles with ASC be remotely hacked to handle like a dirt-tracker?
>> Would be funny to see luxury SUV's spinning like tops.
>>
>
> pull the fuse(s) for the appropriate module(s)...unless of course they
> also feed the ECM....
>
> GW

yeah, but these days, they don't have front/rear pressure proportioning
valves and rely on the electronics. if you pull the fuse, you also pull
pressure distribution management - and you don't want a situation where
the rears are getting the same braking as the fronts.


--
fact check required

On 08/26/2013 02:57 AM, wrote:
> Cars today have ABS, EBD, ESC, "active city stop", self-parking
> and more.
> I am wondering what happens if you upgrade the brakes (not with
> OEM brakes). About 10 years ago, I put bigger rotors and master
> cylinder on a car, and it did not upset the ABS, but that is
> a lot simpler than the modern stuff. I am most worried about
> ESC - I presume that is calibrated by computer simulations and
> road tests with a mad stunt driver. Now suppose your brakes
> have 30% more force than original- would the ESC get it wrong,
> and you end up sideways in a ditch?
>

most "upgrades" play on either different "mu" pads or "weak" effects
like mechanical elasticity. most brake systems have to be able to
compensate for mu, [e.g wet pads] and they do so by reading the tone
ring signals from each wheel.

but for "upgrades", most are typically not as radical as they appear.
few actually increase the piston area [which would require a master
cylinder change to preserve mechanical advantage and thus pedal travel].
they work by way of an "elasticity effect", i.e. single piston calipers
tend to have long bridging of the pad between piston sides and claw
sides - and you can see this if you place two old pads face to face and
see a bowed gap between them. if you go for multiple pistons, that
bowing gets significantly reduced and thus effective pad pressures
increase, even though the hydraulic pressures [total piston areas] are
the same.


--
fact check required