[s-cars] Teen cars

[LL - NY]

It's action/reaction. Since the earth cannot hit the car any harder than car
can hit the earth going at the same rate, the effect is that the barrier
acts like the car is hitting something of equal mass to itself. Due to the
relatively small force on the earth, it essentially does not accelerate. An
Escalade would. Backwards, but not by much. An equal mass car would
accelerate backward at a greater rate than the Escalade.

That was the concept of that allowed the barrier crash to be practical, the
car would only be compared to hitting something of the same mass, which
allows for a uniform, within class tests. Makes things much simpler for the
tester, no multiple crashes nor methods of applying those crashes to get a
relative idea of vehicle crash performance. Newton's 3rd law is one of the
more difficult concepts to grasp, so perhaps the NHTSA site can help with a
better explanation that I can do at the moment.

And, in terms of engineering, new materials, modelling methods, etc, what
those techniques have done has allowed better *optimization* of material for
a given strength, not the actual strength of the structures themselves. It
is entirely possible to emulate the boron steel crash structure of the
modern car (think standard racing roll cages, which for at least the SCCA
MUST be made of mild steel) at the expense of typically weight. FEA existed
when I was in college, and I learned the fundamentals of it, and that was
just shy of 30 years ago. It had been used primarily in the aircraft
industry for years already (where materials optimization was much more
important than in cars, although it's obviously trickling down due to
economy/emissions concerns). The greatest change in terms of engineering *
capability* (as opposed to actual application) I've seen in automobile
safety, really does lie in the interior safety devices, (airbags, interior
impact design, anti-submarine devices), as the space frame concept has
existed for quite awhile. Whether or not it was profitable enough for
manufacturers at the time to do the "safety thing". From marketing
literature at the time, I do know that Saab actually was applying aircraft
engineering principles in their perimeter frame, which I do know from
personal experience existed in their cars frames from the 99 series up to
GM.  As for the UrS, I don't personally know, so I will accept that I *could
* be entirely wrong on the Mini/UrS point. However, if one had to rely on
empirical evidence alone, then the only way we could be sure is to test
every car on car combination. What the video did state was that their
results should result in a re-examination of the mass/mass concept being the
primary factor as a matter of principle for multi-vehicle crashes (it still
matters not in single vehicle crashes), it didn't state that this was a
total principle to apply in all cases. Sure, a well designed smaller vehicle
can "win" vs an older heavier vehicle. But, what if (again, I don't think we
can fairly say all) the heavier vehicle had a better design (I don't recall
740's ever being exceptional in this area, from my recollections of CU
magazine, even all Volvo's aren't necessarily equal) which is entirely
possible. If we had to do it empirically, we'd have to crash every one.

LL - NY

On Wed, Dec 9, 2009 at 11:33 AM, Taka Mizutani <t44tqtro at gmail.com> wrote:

> Again, you're wrong- offset crash tests into a concrete mass are
> effectively infinite mass, far more than an Escalade. How do you explain
> that one?
>
> Also, how do you figure that the engineering in a 30+ year old design is
> better than 30 years later? There was no FEA or other computer modeling back
> then, steel alloys were not as advanced and safety systems were not as
> advanced. Comparing an old car to a new one and saying the old car is safer
> is simply foolish.
>
> I will not discuss how a Saab 99 will do against an Audi Coupe GT, that's
> not what the original discussion was about.
>
> Taka
>
>
>
> On Wed, Dec 9, 2009 at 10:37 AM, LL - NY <larrycleung at gmail.com> wrote:
>
>> One thing not being taken into account (boron steel, non-withstanding) is
>> design. Saab used a similar, for the lack of a better term, perimeter
>> frame
>> on the 99/900 series. It's a rather complicated section tubular frame that
>> surrounds the sides of the passenger compartment, very similar to what the
>> Impreza "perimeter frame (which is the boron steel section), but it's of
>> rather heavy section tubing on the Saab (I was able to inspect it when
>> doing
>> body work on the car). WHAT boron steel (and other higher tech materials)
>> allows for is to make the perimeter frame considerably lighter than the
>> likely heavier similar design/construction framework on the Subaru. As I
>> recall, the failings of the Saab 99 series (up until about '78, when they
>> finally installed a proper collapsing steering column) was in frontal
>> barrier crashes, where Saab's attempt to "hinge away" the steering column
>> didn't quite work in barrier tests. Seemed to work better in more "real
>> world" situations.  My point is side penetration of the 99/900 would be
>> MUCH
>> better than a CGT or 4K, from my estimations, as a former mechanical
>> engineer, and I think passenger compartment *integrity* would be
>> reasonably
>> contemporary. *Survivability*, without the impact mediators such as side
>> airbags and curtain airbags, as with any vehicle without them, would be
>> less
>> than contemporary, however, as our bodies would still flop around
>> (greatest
>> issue, head and neck injuries) inside the mostly intact passenger cell.
>> Hell, that's even an issue with the UrS, (mAC) however, in vehicle/vehicle
>> crashes, mass will always win, which is why Mini still looses (no matter
>> how
>> well it does in single car crashes) when it takes on a 'Sclade. Still, the
>> slicability of the CGT/4K (and it's corresponding lightweight, I think
>> they,
>> even in quattro form, are outweighed by a Mini) pretty well regulates it
>> to
>> be comparatively less safe in terms of crashability, assuming an accident
>> can't be avoided.
>>
>> LL - NY
>>
>> On Wed, Dec 9, 2009 at 10:07 AM, erikaddy at yahoo.com <erikaddy at yahoo.com
>> >wrote:
>>
>> > Not a leap at all.  The construction in a mini will destroy the late 70s
>> > tech in the cgt (or any other car from that era).
>> >
>> > I wasn't suggesting a mini for a teen, I just used that for illustration
>> as
>> > it is a small car available in the US.  You were mentioning the
>> construction
>> > of the cgt in terms of safety and I'm saying almost any 2000+ car makes
>> a
>> > cgt look like a death trap.
>> >
>> > Erik Addy
>>
>
>