Motorists KILLED due to floor mat jamming up gas pedal, including anodfficer and his family

On Oct 8, 9:35*pm, Alan Baker > wrote:
> In article >,
> *"Daniel W. Rouse Jr." > wrote:
>
>
>
>
>
> > "Brent" > wrote in message
> ...
> > > On 2009-10-08, LDC > wrote:
> > >> On Thu, 08 Oct 2009 02:57:03 -0700, Alan Baker
> > > wrote:
>
> > >>>In article
> > >,
> > >>> enough > wrote:
>
> > >>>> If this happens to you, the best thing to do is throw the car in
> > >>>> NEUTRAL, so you keep your power brakes and steering, failing that,
> > >>>> turn off the ignition (note, the Lexus with push button Start requires
> > >>>> you to hold down the button for a few seconds to shut off the engine)
>
> > >>>Why not just use the brake pedal?
>
> > >>>No car anywhere -- with the possible exception of a nitromethane
> > >>>burning, top-fuel dragster -- can overpower the brakes with the engine.
>
> > >>>Not one.
>
> > >> Sorry Alan, that is not true. *It might be true of a stopped vehicle
> > >> but is definitely wrong for a vehicle in motion.
>
> > > Put the myth busters on it. I've seen a car barely able to move because
> > > of the parking brake stuck on one drum brake. I find it hard to believe
> > > that a car with a braking system in good working order would continue to
> > > accelerate once the brakes were applied.
>
> > Sorry, but Mythbusters is primarily a comedy show, with the science
> > obviously being secondary, so I wouldn't give that show full credibility
> > whether or not they bust an alleged myth.
>
> > Recall that this incident involved a moving vehicle, not one starting from a
> > stationary start.
>
> > So then consider the following scenario:
>
> > 1. Go down a grade, say about 6%.
> > 2. Hold the accelerator in position.
> > 3. Apply brakes while still holding down the accelerator... effectively
> > dragging the brakes.
>
> > Yes, your vehicle will begin slowing, but then the rotors will probably
> > start to heat up and you'll feel some braking vibration in the vehicle if
> > you continue riding the brakes. Keep going braking like that, you'll likely
> > permanently warp the rotors. Eventually, you'll start boiling the brake
> > fluid or glazing the brake pads. Glazed pads will require more pedal effort
> > to stop. Boiling brake fluid will eventually result in a very soft and
> > spongy brake pedal with very little braking effectiveness, could eventually
> > cause the pedal to go all the way down to the floor.
>
> My vehicle won't "begin slowing". It will come to a very quick stop. Not
> quite as quick as if I let off the accelerator, but damn near.
>
>
>
> > (Many years ago, I once overheated/boiled brake fluid when a brake shop used
> > too hard of a brake pad for the vehicle's rotors. The problem wasn't evident
> > until such time that I was in bumper to bumper traffic. Then the brake pedal
> > became softer and spongier each time the vehicle slowed to a stop, and I had
> > to exit the freeway immediately until the brakes and brake fluid could cool
> > down, or else I could have had the brake pedal all the way down to the
> > floor. Once the brake shop replaced the pads with a different brake pad, the
> > problem never occurred again.)
>
> Just how "many years ago" was that?
>
>
>
> > Now, then--consider that in this incident, it is reasonable to suspect that
> > the pedal was stuck in the floored (i.e., full down) position, since the 911
> > call transcript shows the caller mentioned going 120 (mph). It's also likely
> > the brake pedal was being pressed as hard as possible for as long as
> > possible to try to slow down the vehicle. So then it's also likely that the
> > brake system could not properly stop the vehicle at full sustained
> > acceleration, given that most passenger vehicles use DOT 3 or DOT 4 brake
> > fluid, not advanced/expensive DOT 5 or DOT 5.1 racing types of brake fluid.
> > Of course, those are all pure guesses on my part, but those guesses are also
> > reasonable considering what the news reports have stated.
>
> If the brakes were function properly, then the stop would only take a
> little longer than a normal stop.
>
> Sorry, but do the math.
>
> --
> Alan Baker
> Vancouver, British Columbia
> <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>- Hide quoted text -
>
> - Show quoted text -

Exactly on all counts. The only way one would boil the fluid is by
not really stomping on the brake.

Harry K

In article >,
Alan Baker > wrote:
>In article > ,
> (Matthew Russotto) wrote:
>
>> In article >,
>> Alan Baker > wrote:
>> >
>> >I did it for you.
>> >
>> >For a 3000 lb vehicle travelling 60 mph, a .9g panic stop dissipates 432
>> >hp.
>>
>> The units aren't right. You dissipate energy, not power.
>
>The units are correct. When you dissipate energy at a certain *rate* per
>second, that's units of power.
>
>> The energy dissipated in that stop (regardless of deceleration) is
>> 11616000 lb*ft^2/s^2. Or about 363000 foot-pounds. Plus whatever
>> energy the car's engine adds over the stop, minus aerodynamic losses.
>
>Now divided that by the time necessary to complete the stop and you'll
>have the average power dissipation.

Average power dissipation is not meaningful in this case. For one
thing, not all the energy is dissipated during the stop. For another,
power dissipation is not constant; it's a function of the temperature
of the brakes and the airflow over them.

>No, but the fact that in reality one can make repeated maximum braking
>stops without serious brake fade pretty much shows that it can...

You can? News to me; I've experienced serious brake fade in such a
situation (on a track).

--
The problem with socialism is there's always
someone with less ability and more need.

In article >,
N8N > wrote:
>
>no, really, I'm not stepping out of character, I'm serious. If we can
>convince manufacturers of the need to upsize brakes, I might not have
>had warped rotors on both of my last two company cars (fairly non-
>aggressively driven, although often I end up using the brakes harder
>than I plan to due to the idiocy/aggressiveness of others...)

It's both an economy and fuel economy thing. Make the rotors smaller and
thinner and they're cheaper AND you reduce unsprung rotating weight.
--
The problem with socialism is there's always
someone with less ability and more need.

In article >,
Alan Baker > wrote:
>
>If the brakes were function properly, then the stop would only take a
>little longer than a normal stop.
>
>Sorry, but do the math.

The math is complicated and requires some numbers we don't have. We
need initial speed, mass of the car, thermal mass of the brakes,
initial temperature of the brakes, temperature at which brake failure
occurs, power output of the engine, deceleration attempted, effective
brake cooling at any given speed, etc.

These things depend on other factors like the age and composition of
the pads (some pads outgas more than others; that can cause brake
failure prior to the fluid boiling), condition of the rotors (warped
rotors will generate more heat for the same decleration), amount of
water in the brake fluid, etc.
--
The problem with socialism is there's always
someone with less ability and more need.

In article > ,
(Matthew Russotto) wrote:

> In article >,
> Alan Baker > wrote:
> >In article > ,
> > (Matthew Russotto) wrote:
> >
> >> In article >,
> >> Alan Baker > wrote:
> >> >
> >> >I did it for you.
> >> >
> >> >For a 3000 lb vehicle travelling 60 mph, a .9g panic stop dissipates 432
> >> >hp.
> >>
> >> The units aren't right. You dissipate energy, not power.
> >
> >The units are correct. When you dissipate energy at a certain *rate* per
> >second, that's units of power.
> >
> >> The energy dissipated in that stop (regardless of deceleration) is
> >> 11616000 lb*ft^2/s^2. Or about 363000 foot-pounds. Plus whatever
> >> energy the car's engine adds over the stop, minus aerodynamic losses.
> >
> >Now divided that by the time necessary to complete the stop and you'll
> >have the average power dissipation.
>
> Average power dissipation is not meaningful in this case. For one
> thing, not all the energy is dissipated during the stop. For another,
> power dissipation is not constant; it's a function of the temperature
> of the brakes and the airflow over them.

No. That's the dissipation of the *heat*. The dissipation of the kinetic
energy is into the braking system.

What I was showing is that the brakes have more than enough retarding
*force* to overcome the engine at full throttle.

>
> >No, but the fact that in reality one can make repeated maximum braking
> >stops without serious brake fade pretty much shows that it can...
>
> You can? News to me; I've experienced serious brake fade in such a
> situation (on a track).

--
Alan Baker
Vancouver, British Columbia
<http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

On Oct 8, 5:57*am, Alan Baker > wrote:
> In article
> >,
>
> *enough > wrote:
> > If this happens to you, the best thing to do is throw the car in
> > NEUTRAL, so you keep your power brakes and steering, failing that,
> > turn off the ignition (note, the Lexus with push button Start requires
> > you to hold down the button for a few seconds to shut off the engine)
>
> Why not just use the brake pedal?
>
> No car anywhere -- with the possible exception of a nitromethane
> burning, top-fuel dragster -- can overpower the brakes with the engine.
>
> Not one.
>
> --
> Alan Baker
> Vancouver, British Columbia
> <http://gallery.me.com/alangbaker/100008/DSCF0162/web.jpg>

You really do not know what you are talking about.


Dave

>>If this happens to you, the best thing to do is throw the car in
>>NEUTRAL, so you keep your power brakes and steering

Agreed! I've never learned manual transmission
but I knew to use 'neutral' (not park) in case of emergency,
such as
- when the engine died while on an uncrowded highway,
neutral let me coast down the hill,
safely steer to the shoulder and stop by the emergency call box.
- when using a rental truck with a broken fuel gauge,
I'd get it up to speed, stall, use neutral to coast,
pull aside, restart, repeat until at gas station.


>>failing that, turn off the ignition

BAD IDEA: that often locks the steering!
For way too much information about that,
a fellow who crashed his car due to that
formed a one-man-crusade against steering wheel locks.

Jeff Jonas wrote:
>>> If this happens to you, the best thing to do is throw the car in
>>> NEUTRAL, so you keep your power brakes and steering
>
> Agreed! I've never learned manual transmission
> but I knew to use 'neutral' (not park) in case of emergency,
> such as
> - when the engine died while on an uncrowded highway,
> neutral let me coast down the hill,
> safely steer to the shoulder and stop by the emergency call box.
> - when using a rental truck with a broken fuel gauge,
> I'd get it up to speed, stall, use neutral to coast,
> pull aside, restart, repeat until at gas station.
>
>
>>> failing that, turn off the ignition
>
> BAD IDEA: that often locks the steering!

No reason why you cant turn the ignition off to kill the engine
and then turn it on again so the steering isnt locked.

> For way too much information about that,
> a fellow who crashed his car due to that
> formed a one-man-crusade against steering wheel locks.

On Oct 24, 1:42*pm, "Rod Speed" > wrote:
> Jeff Jonas wrote:
> >>> If this happens to you, the best thing to do is throw the car in
> >>> NEUTRAL, so you keep your power brakes and steering
>
> > Agreed! I've never learned manual transmission
> > but I knew to use 'neutral' (not park) in case of emergency,
> > such as
> > - when the engine died while on an uncrowded highway,
> > *neutral let me coast down the hill,
> > *safely steer to the shoulder and stop by the emergency call box.
> > - when using a rental truck with a broken fuel gauge,
> > *I'd get it up to speed, stall, use neutral to coast,
> > *pull aside, restart, repeat until at gas station.
>
> >>> failing that, turn off the ignition
>
> > BAD IDEA: that often locks the steering!
>
> No reason why you cant turn the ignition off to kill the engine
> and then turn it on again so the steering isnt locked.
>
> > For way too much information about that,
> > a fellow who crashed his car due to that
> > formed a one-man-crusade against steering wheel locks.

That's expecting waaaay too much thought out of most drivers.

Dave