Seat Bolts
Regarding the article on
fitting new seats to old cars I found it to be very good about how to go about
checking for correct position etc. But I did think that your recommendation to
fit high tensile fasteners to restrain the seats may be not the whole
story.
When building my Cobra kit car we had to do quite a bit of work in
regards to making sure the seats and seatbelt mounting points were compliant
with ADR's of the time. From memory, the engineer that I used (BC Tonkin) said
to me specifically that bolts for attaching restraining systems are not supposed
to be high tensile to allow for deformation during a crash. If the fasteners
used were high tensile, which although they are a higher 'strength' fastener,
during failure they tend to fail catastrophically - as in, shear off completely.
Whereas 'normal' mud metal bolts tend to yield and with some residual capacity
to hold the seat/seatbelt in place.
Musing to myself after reading your
article and looking at the requirement as a failure mode analysis, it also could
be related to what the bolts were attached to. Is the attaching structure overly
strong, meaning deformation loads are carried by the fastener, or is the
structure deformable with the bolts transferring load to the structure with no
deformation themselves.
I suspect that as my Cobra kit car had a very
strong chassis with no deformable structure in the attaching areas for the seats
and seatbelt mounting points, the bolts needed to be able to yield without
failure. A more modern vehicle may use high tension fasteners with a deformable
structure to get around the same requirement.
I think that for the story
it may be better to recommend the existing fasteners be re-used as long as they
are in a suitable condition. But then I suppose you get into arguments
about how well engineered are the seats, mass of the new/old seats etc. Which is
starting to bring back memories about arguments/ discussions I had with the
engineer about what I thought were insignificant details but if I didn't comply
he wouldn't sign off on the vehicle.
Darren Roles
Australia
We’ve seen plenty of hardware store bolts so
weak that just torquing them up normally resulted in failure...
Programmable Ignition
Here's a link for Julian (electric recumbent
bike with suspension thesis) zeept.wordpress.com. Keep up
the great and original articles. Will you be doing an article on the new Silicon
Chip programmable ignition? I plan to use it in conjunction with the DFA I
already have fitted to my car.
Julian Kenny
Australia
We haven’t yet decided whether or not to cover
the Silicon Chip programmable ignition – as it works only on cars with single
coil ignitions, we’re doubtful. (And that link is to a very interesting
machine!)
Missed It
The Chrysler Turbine Car
article was good fun, it would have been better if you mentioned that Rover had
a road-going (prototype) Turbine Car 13 years before, and they even took a
couple to Le Mans in the late '50's with BRM. I seem to remember that one even
finished in the top 10, but I could be mistaken on that.
Blair Coull
Australia
Old Car Crashworthiness
One issue
that may not have been covered yet is modifying vehicles (most likely older
vehicles) for increased crash safety. I thought of the idea during
compliancing for a 15 y.o grey import, in which additional side intrusion bars
were retro-fitted to a coupe. Many of the chassis modifications are
focussed on improving torsional rigidity, so as to assist cornering etc, however
it may be interesting to explore ways that impact resistance could be
increased. For example, I am currently restoring a 1976 260z 2-seater, and
although the car is structurally in as good condition as when built, I suspect
it would get shredded like a tin can in an altercation with some of the SUV's
that people are getting around in nowadays.
Andrew
Australia
We don’t believe that such improvements are
easily made without making major changes like fitting a roll cage.
CB through Stereo
I read this article and loved it - In Car Electronics Tech Tips.
I had one question for anybody knowledgeable. I am on the pursuit of
buying a CB system to put in my car. My car is a new one that has an extra
Auxiliary In to use with MP3 players, CD players, etc. Can I use the external
speaker connection on the CB to directly connect it to my stereo system via the
Auxiliary In to use the car speakers as an external speaker for the CB?
William
United States
That could be done with a speaker to line level
converter but you’d then have to have the sound system permanently set to the
aux input to hear the CB.
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