On Tue, Feb 2, 2010 at 6:38 PM, David Hillman <hillman@planet-torque.com>wrote:
> On Tue, 2 Feb 2010, Michael Porter wrote:
>
>> Umm, that little thing known as kinetic energy? If you're going sixty, the
>> brakes can dissipate that energy reasonably quickly as heat--as long as
>> there's no additional energy being added. However, if that engine is going
>> full chat and producing near peak horsepower, adding to the kinetic energy
>> of the vehicle as the brakes are trying to subtract from it, it's a losing
>> proposition. Physics wins.
>>
>> e_sub_k=m * v-squared
>>
>
> There seem to be a bunch of different scenarios getting confused here.
> Some people, like Michael, are talking about a situation where the engine is
> running wide-open. Maybe it's me, but that seems highly unlikely. I drive
> fast, on the street, and I find myself using full-throttle almost exactly
> never. The only times I've been there in my F150 are on race tracks ( recon
> runs to check an autocross course, and running out to retrieve broken/stuck
> racecars at Autobahn and various frozen lakes in Michigan ). Now granted, a
> fullsize pickup isn't very sporty, but I drive my wife's 295hp Saab
> sometimes, and there's no remotely legal situation where you can get much
> beyond half-throttle. It was very difficult to reach WOT in any
> marginally-powerful sporty car that I've owned.
>
Except, of course, that the toyotas involved have electronic throttles.
There are, at least, *three* different re-callable problems with the cars.
One is that the pedal can become physically stuck by an "improper floor
mat". Second is that (maybe; i'm not convinced this is an actual problem.)
the pedal can become stuck on its own. Third, and one that toyota is doing
its damndest to pretend doesn't exist, is that their software is seriously
fucked up, and causing the throttle to open even without a command to do so
from the pedal. Toyota are being very scummy about the whole process.
They're blaming their sub-contractor, and not acknowledging that they're the
ones at fault.
It seems outrageously unlikely to me that there a bunch of people
> driving...
>
> . Certain 2009-2010 RAV4
> . Certain 2009-2010 Corolla
> . 2009-2010 Matrix
> . 2005-2010 Avalon
> . Certain 2007-2010 Camry
> . Certain 2010 Highlander
> . 2007-2010 Tundra
> . 2008-2010 Sequoia
>
> ...who are getting the pedal to the metal very often.
>
> So if you _aren't_ mashing the gas, I still think the vehicles brakes
> will stop you. And in several of those vehicles, like a 132hp 2010 Corolla,
> I'm still betting on the brakes even if you are.
>
> You've got a lot of faith in brakes. It's misplaced. You'll boil the
fluid in thirty seconds.
> Fwiw, the same Press Release from Toyota ( where I got the vehicle list )
> says;
>
> "In the event that a driver experiences an accelerator pedal that sticks in
> a partial open throttle position or returns slowly to idle position, the
> vehicle can be controlled with firm and steady application of the brakes.
> The brakes should not be pumped repeatedly because it could deplete vacuum
> assist, requiring stronger brake pedal pressure. The vehicle should be
> driven to the nearest safe location, the engine shut off and a Toyota dealer
> contacted for assistance."
>
>
Except, of course, that's there's very good evidence that "the vehicle can
be controlled with firm and astead application" is, at best, sometimes not
true.
> --
> David Hillman
>
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--
David Scheidt
dmscheidt@gmail.com
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