Frank Krygowski wrote:
> Nate Nagel wrote:
>
>> Frank Krygowski wrote:
>>
>>>>> http://www.ou.edu/oupd/nightdr.htm
>>>>
>>>>
>>>
>>> From
>>> http://www.thecarconnection.com/index.asp?n=163,172&sid=172&article=3252:
>>>
>>>
>>> "The usual range of properly aimed headlights is about 150 feet for
>>> low beams and 350 to 400 feet for high beams."
>>>
>>
>> Get some real values and then tell us who should be embarrassed.
>
>
> So far, I'm the only one who's produced values. Do you have some? Put
> them up and we can discuss. If not, you really shouldn't complain about
> mine.
I shouldn't have to, that claim is so ludicrous that it's not even worth
mentioning. For reference, 300-350 feet is the average length of a city
block in many areas. Are you really going to tell me, with a straight
face, that with my high beams on a hazard only a city block away is
going to be near the edge of visibility? Even in the total absence of
other light? (which NEVER is the case, except in the instance of a new
moon in a VERY remote location)
Also, any quotation of seeing distance with relation to headlamps is
automatically suspect, as there are so many variables that must be taken
into consideration - voltage being the main consideration. System
voltage can vary dramatically car to car, as can voltage drop from the
alternator to the headlight socket itself. However, overall headlamp
output is dramatically related to voltage - a difference of a few volts
on a nominal-12V system can actually make an incandescent lamp up to 50%
brighter or dimmer. (don't believe me? Grab a Fluke and pull a dimmer
switch out of the wall, and watch the voltage readings as you dim the
lights. Your house is a nominal 120V so just move the decimal point
over one to translate into automotive terms.) Finally, how does one
define "seeing distance?" The distance at which you see a
retroreflective road sign? A white object on a dark background? An
object almost the same color as the background? You can use different
standards to "prove" almost anything you want to, but the fact remains
that high beams that can't provide illumination that is clearly
acceptable a city block away aren't going to be found on any vehicle *I*
am willing to drive at night.
FWIW the headlights on this car are likely *better* than whatever you're
driving, as it's been my experience that many US-spec "aerodynamic"
composite headlamps are actually inferior to a good halogen sealed beam,
especially if they've got a few years on them and the plastic lenses
have started to cloud. (best would be E-codes, but the owner of this
car didn't want to go that route as they would have probably been a
points deduction. I'm going to have to take him for a ride in my 944
now that I have E-codes installed with a relay harness - he may change
his mind. Then again, he probably won't - he will likely never drive
this car after dark again; it is a show car after all.)
>
>>>
>>> I'm sure that in your mind, the Studebaker was _much_ better at panic
>>> stops than a typical car, right? ;-)
>>
>>
>>
>> In my mind, as well as the minds of most automotive writers of the era.
>
>
> When I said "The typical car," I meant of _this_ era. The websites I
> listed were contemporary - not 1963 vintage!
Most of the advances in braking technology over the past 40 years have
been in three areas - one, making the brakes more resistant to fading
(which was apparently not a problem with the Stude brakes.) Two, making
them easier to modulate (i.e. "threshold brake") in a panic stop
situation. Three, electronic controls to take the responsibility for
threshold braking away from the driver (which kind of negates advance
number two, if you think about it.)
The BIGGEST advance in brakes, however, hasn't been the brakes
themselves - it's the TIRES. Unless you're driving a vehicle with
sorely defective brakes, and/or have fitted ridiculously sticky race
tires to your vehicle, you will be able to lock 'em up at any speed,
simply by pushing harder on the brake pedal. Bigger, sexier brakes
aren't going to make you stop any quicker - they're only going to allow
you to stop MORE OFTEN (i.e. fade resistance.) Bigger calipers are
often more stable as well, allowing better control and modulation by the
driver. But the basics remain the same.
So anyway, as with most cars, the characteristics of the vehicle's
brakes are more or less irrelevant in this particular instance. In a
single panic stop from normal traffic speeds, fade should not be a
factor (although, of course, it's sadly entirely possible to find
examples of vehicles with deficient base brake systems, but that's not
what we're dealing with here.) What we're concerned with here are the
tires, as they will be the limiting factor in a single panic stop
situation. Now I did state that this car had bias plies on it, which
are admittedly inferior to modern radials. However, they're not *that*
bad in acceleration or braking - their biggest shortcoming is in
accepting lateral forces i.e. cornering. Still and all they can't be
expected to perform like a new tire, let's be very conservative and say
that they can handle a max of 0.5G in the fore-aft direction. That's
*half* of what a good modern radial should be able to handle under ideal
conditions (even modern tires are still slightly better at acceleration
and braking than they are at cornering, so while 1.0G of cornering is
excellent, although becoming more and more common, 1.0G braking isn't
nearly so noteworthy.) I think that's a very low number, I don't think
they're quite *that* bad, but I'll use it just so I can't be accused of
not being conservative enough. At 100 ft/s (a hair under 70 MPH) it
would therefore take a little over 300 feet to stop not counting
reaction time. Therefore even if near asleep at the wheel, it should be
possible to stop in under 400 feet.
>
> The rest of your post amounts to exactly what I predicted: that boy,
> that old Studebaker had terrific brakes! And its headlights were perfect
> or better! And this rural two lane road was guaranteed to be straight,
> well-paved and deserted. And that if anything _did_ happen, of _course_
> it would have been taken care of with perfect aplomb. And as a last
> tidbit, naturally, you're a better than average driver - just like 85%
> of the American drivers surveyed.
Yes, although I realize you meant that sarcastically, that about sums
the situation up exactly.
>
> And as evidence of all that, we have ... well, actually, all we have are
> your admission of nearly losing it on a freeway, and your personal need
> for super-accurate speed advisory signs.
you are confusing "need" and "want." There are very few situations
where one actually "needs" advisory signs at all.
>
> IOW, You're making no sense. And you're demonstrating in every way
> possible that you can't be trusted to drive responsibly, to choose your
> own reasonable speed. You make a _strong_ case for strict speed limit
> enforcement.
>
Where you come to that conclusion from my posts is beyond me.
nate
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