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Discussion Starter · #1 ·
I just purchased the D-Cel device from the people that make the Huthcens device and should have it by Friday. I chose the D-Cell because of the the side protection it offers, ease of access into and out of the car that it allows, and $425 seemed like a reasonable amount of money. Apparently the Hans and Hutchens Devices only provide protection for frontal or near frontal impacts. While the D-cel and Simpson(which is made by the Hutchens folks for Simpson) claim to provide almost as good frontal protection as the Hutchens/Hans to a certain speed, but the D-Cel also provides side protection. What I distilled it down to is that while the Hans and Hutchens device do a better job at higher speed on frontal impacts, I would like more side impact protection. Additionally, the D-cel is a harness that you wear, so you can get into and out of the car quickly to change flats, which my co-driver seems to cause a lot of. I'll let you know how it fits and installs(ugh, drilling holes in my new helmet), and hope I never get to tell you how well it works. Also I use a Bell full face helmet, and Hutchens said you would not receive all the benifits using a open face helmet, but you would get some side protection from the D-cel.

Here are the sites check them out:

http://www.hutchensdevice.com/

http://www.hansdevice.com/

http://www.over40racing.com/

http://simpsonracing.com/Shop/ShowProduct.asp?category=75&Product=525


Sincerely,
Preston
 

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Preston;

I don't know exactly what the rule book says in the States, but in Canada, our rule book says that ANY modifications to a helmet renders it illegal for use in rallies.

We can't drill holes in our helmets (unless we're wearing them :p). Make sure you're allowed to, before you do this. Anybody know if the American rule book says anything about this?

Dave
 

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If, stress IF, drilling holes in the helmet is authorized by both the helmet and device manufacturers, then the rule is outdated and incorrect, and should be fixed. Otherwise, DO NOT modify your helmet in any way. It's your (irreplacable and largely unrepairable) head we're talking about here.
 

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Discussion Starter · #4 ·
Good point on the rules, I will re-check but I beleive that drilling holes is required for all these "devices" including the Hans and Hutchens devices that are mandated by some racing governing bodies. Calling Bell, the SCCA and Huthcens as soon as I am done writing this.
 

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Please let us know what you find as we should submit rules changes to accomodate these devices. On a technical level the debate is obviously between the helmet manufacturers and the device manufacturers; but as soon as we know where they stand we have to get it in the rules right away.

ACP
Flirting with the laws of physics.
 

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>If, stress IF, drilling holes in the helmet is authorized by
>both the helmet and device manufacturers, then the rule is
>outdated and incorrect, and should be fixed.

The exact wording of the CARS rule is: "No helmet may be modified from its specification as manufactured, except in compliance with instructions approved by the manufacturer. Any other modification will render the helmet unacceptable."

I doubt that we would see any change to that wording. If drilling holes to mount a restraint system weakens the helmet, the restraint system might not even hold, plus you've now compromised the integrity of the helmet. Be very careful before doing anything creative with your safety equipment.
 

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Is there anyway to send the helmet either to the helmet manufacturer or the device manufacturer, and have them do the drilling and installation?

I would hate to take my ordinary house drill and crack the shell when I drill through it. Even a tiny, almost-invisible crack could become dangerous the first time the helmet is stressed in a crash......
 

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I know the HANS device people will do it for free with the purchase of one of their systems, and they now offer a do-it-yourself kit...
 

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There are some great aircraft adhesives that could be used, again check with the makers of the helmet and the system that you decide on.
Brian Scott (AZ) has ordered the D-Cell system along with a full face helmet because of mounting to try at Maine. I will try the system on myself to see how it works from the Co-driver's side.

David Hackett
Co-driver
#96 Focus SVT G2
 

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>I just purchased the D-Cel device from the people that make
>the Huthcens device and should have it by Friday. I chose
>the D-Cell because of the the side protection it offers...<snip>

I could not find a reference to it's side protection. Would you point me to one?


>...Apparently the Hans and Hutchens Devices only provide protection >for frontal or near frontal impacts.

Where is this stated?


>While the D-cel and
>Simpson(which is made by the Hutchens folks for Simpson)
>claim to provide almost as good frontal protection as the
>Hutchens/Hans to a certain speed...

I found only a reference to the D-Cel reducing HIC, max Gs, & neck *tension* in the ad material, the latter confirmed in that Sae paper I reference in the other HANS thread (2002-01-3304)...but only to the injury threshold in a 35mph/56kph delta/50g deceleration. It seems to do a good job reducing neck twisting.

Conversely, rearward neck shear is only slightly reduced over baseline w/ the D-Cel.


>....while the Hans and Hutchens device do a better job at
>higher speed on frontal impacts...<snip>

?? It appears that the Hutchens & D-Cel perform at about the same level. The HANS outperforms both...tho the neck compression is slightly higher than baseline (still way below injury threshold), probably due to the dynamics of the device (pulls down w/ seat belt tension).
 

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Discussion Starter · #12 ·
Reference to the side protection was from the tech on the phone at Hutchens who said the Hutchens device does not provide side impact protection and directed me to the D-Cel which he said does. The Hans tech said that the Hans device would stop the twisting motion of the head but not provide direct side motion protection. Also one of the people I spoke to at the SCCA said they only had data for frontal impacts on the Hans and Hutchens device. Please call them yourself and see if you can glean better or different info than I did.

More questions:

Is the improvement in frontal impact from the HANS worth at least twice the money? Is that improvement more important then the claimed(on the phone) side impact protection offered by the D-Cel? Or is it more important to have protection against a twisting motion than a side motion? and is it better to have a few small holes in a helmet below the test line and have neck protection or no holes with no neck protection?

I tried to get the SAE article but got caught in some bureaucratic loop on their site, could you send it to me.
 

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rallymeister


We can debate the negatives all day long but at the end of the day the bottom line is for 450.00 + helmet my neck will not move as much in a crash with the D- Cell. You dont have to be a rocket scientist to look at the data and figure it out. You can talk to the manufactures all day long no ones going to guarrantee that any of these devices will save your life, Maybe if we could tell them how fast or at what angle we are going to hit that 3 ft. pine tree then they might have something to work with. In the meantime all we have is existing info from the pavement panzies to work with and that is good enough for me.

rallymeister/ #96
 

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Preston & rallymeister

Preston: Check your e-mail.

rallymeister: We were "debating negatives"?
 

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>I don't know exactly what the rule book says in the States,

The SCCA rulebook is silent on the issue of modifying a helmet to allow for the attachment of a supplemental restraint system.

I _believe_ that the SFI/FIA certifications address the helmet structure only above the cheekbones, and so modifications required for supplemental restraint systems fall outside of these certifications.

In short, if you compete in the SCCA and wish to wear a HANS or other supplemental restraint device, you are welcome to do so.

Thanks,
- Christian

Bjorn Christian Edstrom
Co-Driver
 
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RE: Preston & rallymeister

Have cars with cages been modelled in something the LS-Dyna3d or a similar FEA program?

I'm absolutely a bit of a ninny. I've been wondering about side airbags as well.

Any thoughts on either Sean?
 

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Neck Braces

Here?s my 2 cents. If you wear a full-face helmet it is stronger laterally. If you combine this with a standard neck brace you will reduce the speed in which your head moves and the distance it travels in a crash. Neck Braces are readily available and legal; but I see very few rally drivers wearing them?

This combination does not take long to get used to. I started wearing them after a season of karting because it was mandatory. It did not reduce my lateral visibility and did not constrain me in any way. I personally would not where a Hans type devise in a rally car because in rally there are other factors such as wild life branches etc.. that may find there way inside. It is nice to think that should you need to move to avoid these potential hazards that you could do so.
 

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Discussion Starter · #18 ·
RE: Neck Braces

The Hutchens folks strongly put down the foam neck collars by themselves, I think they said it could add to the leverage being placed on your neck, but they also said it would have some benefit when used with a Hutchens or D-Cel. I can only assume they have tested this stuff. One of the articles I read said you would miss the collar anyway as your head moved forward. One of the folks I talked to said that those collars were originally designed by the off-road truck folks to reduce neck fatigue, not for safety during an accident.
 

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RE: Neck Braces

The leverage issue in regard to the neck brace is a good factor to consider for sure. You would definetely miss the neck brace in a front impact if you were wearing an open helmet. With a full face helmet it would be very hard to miss the brace. I guess every item has its positives and negatives... Do you know how the Hans effects the brain. If you prevent your head from moving what happens to your brain? does it keep going, logic would probably say yes? Have they got much data on this aspect?
 

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Discussion Starter · #20 ·
RE: Neck Braces

Either Hans or Hutchens answers that on their web site frequently asked questions, check the links I posted above, I can't remember exactly what they said.

Preston
 
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