[s-cars] Teen cars

[Taka Mizutani]

I don't have the time to expound on your post thoroughly, but offset crash
performance of older cars is very poor compared to newer cars. Calling a c3
audi or a 900 series Volvo good is a joke. If you pull video of older,
supposedly safe cars doing the current euro ncap test, you'd be shocked how
poorly they perform. You're arguing a ridiculous point. Don't take it
personally, it makes no difference what your credentials are.

My point is that newer cars are much safer. There is no comparison between a
10 or 30 yr old car vs current tech. It has everything to do with energy
absorbing structural design and designing the car to do well in more
realistic crashes.

You are absolutely wrong about structural integrity of older cars in crash
tests, especially offset collisions. Even a top rated car of its day like a
w126 s class is a poor performer today. The biggest issue is preserving the
passenger compartment, which old cars do not do.

I'm not going to argue this point any further because you insist on points
that cannot be supported by current crash data and falling back on your
credentials in an attempt to bolster your argument is not helping your case.
This is a discussion, not a personal attack. If you insist on being a
proponent of incorrect information, I'll keep on hammering this home.

Taka

On Dec 9, 2009 4:20 PM, "LL - NY" <larrycleung at gmail.com> wrote:

I am not trivializing things. I believe that empirical data from one crash
video (I'm not counting the '59 Impala with the current Malibu, that's
taking things too far back) and calling that totally generalized trend is
going too far. There WERE some well crash designed vehicles from the later
80's that could fare fairly well in terms of passenger compartment integrity
(as Paul points out, even early Benz's and many 50's 'Murican cars, could do
that, albeit w/o functioning crush zones) and by the mid-eighties energy
absorption was achieved externally by means of crush zones, internally with
frontal airbags appropriate collapsing internal structures designed to lower
the internal acceleration of the occupants.  Heck, in a frontal collision, a
1989 C3 actually does very well, by means of airbags, seatbelt tensioners,
and overall structural design. The concept described by the lay people of
the media called "energy channeling" is kind of bull. That would imply that
the energy (and the reality here is we are looking at forces, not energy) is
not "channeled" to places unknown (in that Fifth Gear video, was there any
damage, thus implying work, thus implying forces to the REAR of the Renault?
If so, THEN energy was somehow transferred to the rear of the car, if not,
it was absorbed by the front of the car, and by the kinetic energy of the
Renault, which bounced back considerably more than the Volvo, and was
displaced from the point of impact further, indicating a greater kinetic
energy change. What the Renault did that the Volvo didn't do there goes
directly to my point, INTERNAL *management* of crash forces has improved
tremendously. Airbags, crushable interior panels, side and curtain airbags,
have seen the greatest improvements, thus making the Renault the better of
the two cars demo'd in the video. That the Volvo was the weaker of the two
structurally was a result of the vehicle selected, it was chosen on rep, but
I'd venture a contemporary M-B (were they called E-class back then) would've
fared considerably better.  Structurally, were 30 year old designs as
consistent? No. But were they possible and put into practice by some? I'd
say the answer is a likely unproven (unless someone wants to go out and
crash some cars), yes. I just don't think it's justifiable to put ALL of the
older vehicles in one catagory there.

As for FEA, the concept is practically applied using computers (because of
the tedium involved) but it is capable of manual application. It doesn't
take a super computer to do the work. The incentive (as in profit margin)
wasn't as there in the 80's, so few (I believe actually M-B was applying it
as was probably Saab, since it would've tricked down from their aircraft arm
back when they were one and the same) would do it, but the technology was
there, and it was doable with the computing equipment at the time, we were
doing it in my 400's level design class.  I agree, the black box data has
improved things (and no, there were no auto applications then). but I
digress, the biggest gains in safety has come from the management of forces
(thus, passenger accelerations which are still directly proportional to
forces) in the interior, particularly in side impacts. Frontal impact
improvements have been comparatively smaller (I don't mean non-existent,
just to be perfectly clear, particularly in the lower extremity region) than
side. But Chris' original post was about a header, not a T-bone or offset
crash.

I'm not sure if somehow I haven't been clear in my earlier posts, but I did
actually state all of this in them. Re-read them if you care to and you'll
see what I mean. I did spend 8 years in the Engineering field with both
static and dynamic systems, and by the nature of my teaching continue to
study the concepts. Generally, empirical data is either the beginning or the
endpoint of the "theory", not the whole kit and kaboodle.

LL - NY

On Wed, Dec 9, 2009 at 1:04 PM, Taka Mizutani <t44tqtro at gmail.com> wrote: >
> I think you're trivi...