Tech Inspections - Serious Bidness (Page 3 of 3)

Jay gave us the OK for our new seat head rest support attached to the back brace. Was quick and easy to make out of scrap angle iron.

We had to add a hoop behind the fuel cell to brace it against rear end impact, this was made up at the track to pass tech.

ebay special the seat itself had never been fitted, in great condition, must have sat in the sun somewhere for a long time.

As long as that plate is thick enough so the pipe wont impale, that should be plenty enough.  From what I gathered, it does not matter how you support the head rest as long as it's strong and safe. 

If your seat moves forward just make sure that gap does not get too large.

Looks good to me.

Now you got me thinking about our seat back brace...  it has an impaler ..

I'm not sure if Jay was thinking about failing us, or was just going to give us a "don't come back like this" talking to.  The conversation was a bit disjointed because he started a sentence with "Did I talk to you about..."  stopped, looked at the rear stay plates in reference to the rear tires and then finished with "...nevermind, the rear edge of your rear stays are even with the rear of your tires."
Since I was sweating two cars through tech with the same seat brace issue, I was just happy he stopped talking.

Cool, yeah I need to talk to Jay and John at the race about what to do with the spitwad for 2013. Assuming its still alive after this race.

Spank correctly points out the benefit that would be conferred by having a physical restraint system that would accomodate the driver body's displacement in a controlled fashion, that allowed for the rapid distribution of force in a uniform manner, away from the head and neck. Sort of a crumple zone that comprised the seat and seat support. But there is nothing to 'slow the brain' during rapid deceleration since the brain box (helmeted head) is traveling through empty space immediately after a collision. The head will be slowed by either 1)the deceleration force applied by the neck or 2)the deceleration force applied by whatever the head hits.    The rapid deceleration of the brain within the skull is what leads to the most serious head injury patterns and diminishing the force of this "second impact" is of paramount importance in the science of safety in high kinetic energy sports. Indeed, the leading cause of death in motor racing is rapid deceleration of the head and neck that leads to either direct impact forces (brain suspended inside skull slamming against the inside of the skull) or shearing forces between two adjacent anatomical structures (brain and its arteries, two cervical vertebrae.)   I would be very interested to see if any racing seat has been designed to structurally deform in such a way as to provide the controlled decelerative benefit that Spank alludes to.

That being said, preventing headrest failure is likely more specifically an issue of cervical spine protection, as Scotty said on page 1. Failure of the headrest could potentially cause hyperextension of the cervical spine which-while often not as ominous and potentially devastating as a hyperflexion injury-can be fatal or paralyzing. The use of a HANS-type device should mitigate this risk but not completely eliminate it since the posterior deflection of the head could also deflect the HANS if the belts failed or came free of the lips on the device during a collision. It seems to me the safest circumstance for the driver's neck would be to prevent that posterior deflection in the first place, by preventing rearward failure of the headrest. And use of a HANS-type device, like bigds01 pointed out.

As for the fear of impaling your heads and spines on your seat supports, that is a question of metallurgy and beyond my understanding. Seems to me, though, your support arms could be made either 1)extremely broad, across the entire width of the seat or 2)'H' or 'Y' shaped (a la BigShabowski) such that the arms do not terminate directly behind the driver's midline.