gbaker

So call them. Tell Trevor to pump some data this way.

Well, let's see. With the Isaac, after the first impact everything is in place except for one belt connector being at or slightly anterior to the midline of the shoulder. It will still provide outstanding lateral protection and probably very good frontal protection, although possibly diminished due to the shock being extended.

Oh, and the shoulder belts are on.

The HANS: No shoulder belt.

The R3: No shoulder belt.

Any rational driver would choose the Isaac for a multiple impact scenario. Why? Because they still have two shoulder belts.

Regarding the numbers promised earlier, in order of safety priority:
Fz = 2,211N
Nij=1.00 (I know, but the mounts were too posterior)
Mx=10.00Nm (Yeah, baby!)
Nt in Flexion was 0.586
Nt in Extension was 0.863

Tell Trevor to get it while it's hot.

gbaker

Bingo.

Plus, the Snell cert is voided once you drill a hole for the helmet mount. The only way around that (open to interpretation, I know) is to use an adhesive.

RedlineMan

Now now...

Geo

No interpretation necessary. This is from Snell's web site:

"Cosmetic changes to certified headgear are permissible. Such changes are generally limited to marking or trimming the headgear with manufacturer approved paint or tape. Otherwise, modifications to certified headgear effectively create new configurations which shall not have the confidence and certification of the Foundation until properly evaluated. Manufacturers must not place the Foundation's certification label in any modified headgear without the Foundation’s written authorization.

The Foundation recommends that helmet owners not modify or contract someone else to modify their helmets. Any structural modification may adversely affect a helmet's protective capability. The Foundation’s certification and, quite likely, all manufacturer warranties apply to the headgear only in its as manufactured condition. "

Attaching items with adhesive is no different from drilling the shell from the standpoint of Snell.

I'm not writing this to push drilling vs glue and vise-versa. I'm simply pointing out the irony that the simple act of attaching a H&N restraint is in violation of the Snell rating. In many cases (most?) painting is as well. So is drilling for drink tubes, attaching radio gear, etc. All of these things are things amateurs and pros alike do. That will not change either.

The point is that sometimes the arguments put forth about helmets and H&N restraints just go to a place of irrelevance. As I've said before, too many H&N restraint discussions become holy wars.

gbaker

Aw, c'mon John. It's Christmas. Let the love flow.

RedlineMan

C'mon Lew;

I know you don't believe this. Sure, there's always at least a bit of flotsum, but there's got to be some good kernels here, even for you lofty engineers. Or, have you already thought of everything everyone is bringing up? If so... why hold back on us?

You never know when you might come upon a one legged man with a 36" vertical leap!

RedlineMan

Yeh... right.

Suddenly forget that the real world deals in ENGLISH?

gbaker

Well put. One might suggest that all the test data be publicly available so drivers can decide what to do to best protect themselves.

gbaker

That hurts, John. Geez, just when I was headed out...

Short English summary:

Fx/upper neck tension (the important measure): As good as it gets. This will cover you up to something like 150Gs+.

Nij/front-to-rear bending: We were at the absolute limit, but we grabbed a helmet off the shelf that would maximize the measure. We knew that going in.

Mx/lateral head torque, that which tends to pop your head off your neck like a bottle cap off a Budweiser: Blew everyone out of the water. Not even close.

The Nt stuff is a "normalized" value for neck tension, sort of. Anything under 1.00 is safe.

ltc

There are some interesting kernels, it's just hard to pick them out of the bucket with everyone else who's already "popped". As George mentioned, everytime H&N restraints come up, it turns into a 'Holy War'. This one is the best example yet.
It's not so much holding back, and no I haven't thought of everything because there is no such thing as everything with respect to H&N restraints. It's a game of optimization and assigning probabilities.
I've watched H&N development over the past few years (I was at Daytona on the radio when Earnhardt died). From that day forward I told my wife I know exactly how H&D were going to proceed. They have not surprised me. Rather, I am rather disgusted in their approach to 'marketing' and 'standards'. It is NOT design/performance driven. I've seen this 'movie' many times before, both in commercial and military scenarios, and it always comes out the same way....the 800# gorilla always wins. It's not really about technical merit, it's about making sure no one gets to eat enough to become a 900# gorilla.
Yes, I remember Beta vs. VHS, Windows/Intel vs Mac/Motorola, the YB49 vs the B36 (amazing story BTW). ISAAC vs R3 vs HANS....different story, same ending.
I'm not a professional racer, not a club racer, have no desire to race. I'm just an amateur who uses PCA DE as my one opportunity to relax and enjoy my car and meet some great people. As long as I'm comfortable with my personal choices regarding safety equipment, that's all that matters to me. If I make a mistake regarding my safety equipment choices if/when I 'screw the pooch', I'm the only one I'll end up hurting, not my fellow drivers.
This is true......as I said, you can't design for all possibilities

RedlineMan

Hey;

You're alright, Lew. I just had to muss yuz up a bit for getting so cynical.

ltc

Thanks John, I needed and appreciate that.

Perhaps cynicism (maybe skepticism is a better word) is merely a self defense mechanism in situations such as this.
Logic is out the window, there are different forces at work here.

For example:
If an R3 device is SFI38.1 certified, then why can't it be used in NA$CAR?

Is the only metric merely "passing and becoming SFI38.1 certified"? What if one device JUST barely passes certification requirements/load reduction and another CLEARLY exceeds the requirements?
Are all certified SFI38.1 devices created equal? Is one better than another?

How would one know? How would one find out? Would it be possible to get the submitted data/test reports DIRECTLY from SFI? (write them and ask...see what their reply is). Would you have to rely on manufacturer's data? A web forum such as this?
(I will defer the data submittal procedure/discussion for SFI38.1 for another time and place)

As I had mentioned in an earlier thread, next season my son will be required to wear an SFI20.1 rib/chest protector (all Junior and Kid class karters; unfortunately a child was killed by blunt chest trauma in an incident). This same discussion is being repeated by very concerned parents over the various protectors, questions on non certified protectors which have been used previously, etc.
(as an aside, there has also been discussions regarding the use of the R3 in karting, but I don't quite see how you could wear such a device in a hard shell karting seat).

Perhaps it's a parental reponse, but I am much more concerned about the issues surrounding my son's SFI chest protector than I am about my SFI H&N restraint.
This is probably the main reason I got interested in an SFI38.1 thread. I have no axe to grind in this discussion; merely an interested observer and sometimes participant.

RedlineMan

And your observations - whether personally or professionally filtered - are always highly relevant and useful!

You raise points that are in the back of my mind as well. Time and again I think we can all see the need for an independant testing group to put the straight scoop out there. ALL of it. I think there is enough evidence to strongly suggest that left to the manufacturers, data provided to an organization such has HR.org will be highly... ummm... filtered in some cases.

That is not nearly helpful.

David K.

It's Like fighting City Hall!

LFT/Safety Solutions Got you covered there!

Top Dog Chest Protector: Carbon Fiber Chest Protector SFI 20.1 approved

ltc

Perhaps it is like fighting City Hall, but a valid question none the less.
I would be VERY interested in an answer from someone...however I do not expect one to be forthcoming.

In this case (NA$CAR), the merit/advantage of having an SFI38.1 certification apparently does nothing, at least in the case of the R3. The sanctioning body has decided that ONE SFI38.1 device (HANS) is better than the other SFI38.1 devices.....a fairly bizarre situation from a standards perspective.

Many people have stated previously that they don't want to purchase a H&N restraint (ISAAC) that would/may not be allowed by their race series, presumably because SFI38.1 would be a requirement. I posted some links to 2 sanctioning bodies who have taken this stance.

However, it would not appear (and I could be wrong, if so, someon please correct me) that NA$CAR and the FIA (for ALL of its sanctioned series; phased in 2008 thru 2009: F1, WRC, etc)
http://uk.sports.yahoo.com/051210/23/fh9f.html
that only ONE SFI38.1 H&N restraint is allowed.

What does this say for the SFI38.1 certification? How relevant in fact is it?
Do these sanctioning bodies know something that SFI does not?

(As I've mentioned before, by following this line of 'reasoning' and actions, it is NOT that far fetched to assume that a specific harness manufacturer could be mandated; irregardless of any FIA/SFI certification on the harnesses.)

Privately, most of us will all acknowledge what the answers to these questions are.