Geo

Lewis, the sternum strap is not driver friendly either. Doc Melvin found in his research that it changes the loading on the driver's body and actually can cause internal injuries by loading the rib cage instead of the shoulders. It's your body, but that bit of information was pretty sobering.

While that may be true, the way it was presented was as if all teams used it and seemed to be presented as if this was a necessity due to a shortcoming of the product. I know Gregg has mentioned video of tests with the belts slipping off, but that is rather incomplete information, i.e. we don't know any other details such as were they early tests, recent tests, did they discover something that they needed to (and did) correct, is that how they came to determine the specific belt mounting requirements, etc.

Lewis, I couldn't have said it better myself. I made my own choice based upon my beliefs and opinions. Others should do the same. But this shouldn't become a Holy War which it seems like it is everywhere the H&N restraints are discussed. Both the HANS and the Isaac are good products (and the R3 looks promising although I've never seen one in person). I've met Gregg and trust him. He's a good guy and I know he takes care of his drivers. I don't know why folks become so passionate that they feel they must convert others to their choice.

Geo

OK, FBB. Sorry. It just seemed less than objective. No sweat.

I'm still curious about the slippage. Without a lot of other information, we don't know the full story. My guess is the belt mounting requirements are a result of belts slipping in tests. But who knows? Certainly none of us.

ltc

FBB,
It's described a bit in this thread:
https://rennlist.com/forums/racing-and-drivers-education-forum/174889-question-regarding-2-lap-belts.html

I have been to HMSMotorsport (US Master distributor/importer for Schroth) up here in MA and seen the harness.
It is NOT for sale to normal folks like us, only available to professional race teams (NA$CAR, F1 and IRL). They said it was very expensive, as they are handmade in low quantities now. Of course, this may all change in the future.

Adam Richman

George, I hope my comments were not taken as such. I have always been careful to try separate my faith in the Isaac from being a comparative against another product. I too believe that there are not bad H&N support devices, just ones that work with varying degrees of success. My comments were simply a response to ColorChange's comment about no real world testing of the product and for that alone, I feel I can make a real world comment.

I think it goes without saying that in any instance of a wreck, its the concert of all the safety equipment and its placement, use, installation that ultimately saves the day. The best H&N restraint in the world worn with slack harnesses is probably not going to do much. The same could be said for unpadded roll cage in close proximity to the head or arms. The same could be said for an incorrectly mounted seat. The same could be said for a number of things that we might be taking for granted when discussing the ultimate value of H&N restraints - we really have to make sure all our ducks are in a row and not feel that the "correct CHOICE" of a H&N restraint will afford us a false sense of security.

As much faith as I have in the Isaac device, I had Walt build me an extremely protective cage for my 2140lbs. car, I carry a Halon fire system and hand held bottle, am custom fitting the window net, running an interior net, located the kill switch so I can hit it belted in AND I never will take the track w/out my trusty Isaac.

BUT that's not to say I think my friends that run a HANs have made a poor decision, I think they have made a great one too. I only think they've made a crap decision if they skimp on the other safety equipment to get themselves to the track more quickly.

gbaker

This is the best comparative data we can find: http://www.isaacdirect.com/html/chart.html

The only variable is the product being tested.

gbaker

A photo is here: http://www.isaacdirect.com/images/IMG_0381.JPG

You can see the 2" belts (Schroth label) that are intended to hold the HANS in place. They are mounted inside the 3" shoulder belts.

IIRC, David Coulthard came up with this idea.

gbaker

It was a closed test conducted by NASCAR in December of 2002 at the Delphi sled. Non disclosure agreements were required of all participants, so you won't find any video or data. The media has tried.

Having observed this over the years, George, I have concluded that,

1) It is not a bad thing that drivers become passionate about their recent safety purchase. They have spent a lot of resources on the decision and should be proud that they are ahead of the curve.

2) It is basic psychology: You make a decision and you defend it. It's like going to Yale and spending the rest of your life running down Harvard, or vice versa. If you want to see things get really nasty, throw some Lamborghini and Ferrari owners in the same room, lock the door and come back an hour later. You'll need a mop to clean up the blood.

Silly really.

The only time we get fired up is when certain parties pretend they make the only high-performance H&N restraint.

gbaker

There was some discussion about head motion and fit. This question comes up so often that we recently began collecting short videos, which are much better than stills for this purpose.

This page is under constructino: http://www.isaacdirect.com/html/OtherPages/Videos.html

(Anyone know how to rotate that guy?)

gbaker

Hell Adam, you are a platinum member of the Isaac crash club.

At the risk of sounding like a salesman, I want you guys to pay attention to what Adam is saying. Those who have crashed are the ones who become true believers. We see this all the time. A guy goes into the woods at 130 and has neck pain for 3 months, then he buys a H&N restraint and starts preaching safety from the mountain tops.

Like most drivers, I don't believe that every driver needs a H&N restaint in every situation. Doing parade laps in your vintage car twice a year is a good example. But even at a DE, stuff happens--wheels break, tires go down, dirt gets thrown on the track. I don't know where to draw the line, but it is probably safe to say that drivers are at more risk than they think.

The good news is that if you safety prep as well as Adam does, you can survive something resembling a small explosion.

RedlineMan

Hey all;

Gregg - Once again I'd like to thank you for your participation. You are doing a lot to inform everyone, and that is much to your credit.

Regarding the seat back infringement issue. Yes, it can exist. In my case, I relieved the inside portion of the headrest area of my Kirkey seat cover of some of its padding. This solved the problem for me.

As I mentioned earlier, each and every item you add to a system will effect all the other items it interacts with. You cannot expect to buy ANY product that will seamlessly fit into such a complicated scheme as a seating arrangment without having to do some tweaking... just like you did when you put in the previous equipment.

I don't know of anyone who successfully drives with their head pressed into the headrest in the first place. On bumpy tracks, your head will be bouncing around and your helmet will be resting on the bridge of the nose! But I digress...

What you need to do to solve this in a seat that cannot be modified (plastic) is play with the rake of the seat. Hopefully, you will have some room under your thighs that will allow the seat base to be raked up in the front slightly more than it is now. This will also obviously decline the rake of the seat back, and therefore give you HANS clearance.

Hopefully you have a side mount seat arrangement. This is the eaisest to tweak properly. You need to make this adjustment by removing the front mount bolts and use the rear pair as the pivot. Only a slight movement of the seat at the front mount point will give you the required 0.5-1" relief you need.

This may also have the consequent effect of increasing your steering wheel reach. You will then obviously have to fiddle with the setback of the seat to optimize reach with this new setup. In most cases, these tweaks will solve the problem.

Another thing that I happen to think is important with HANS use is make sure the unit is all the way back as far as it will go. When I set my belts to final taughtness, I then press my head back as far as I can. This slides the HANS back against the headrest. There is no documentation that I am aware of that suggests this, but my intution (based on my understanding of the bio-mechanics involved) tells me this is the best position for it to be in.

Geo

Hey man, I never argue with a crash test dummy.

In all seriousness, no, I did not take it as such. Shoot son, you have actually tested the product and that speaks volumes to me.

Maybe I'm a bit over sensitive to the Holy Wars of H&N restraints, but I frequent the following boards where this war has been waged on more than one occasion:

Rennlist Racing
Bimmerforums Racing
Improved Touring Forum
Pelican Racing

The arguments are not always the same and sometimes one will favor one device while another forum will favor the other. It just gets so counter-productive IMHO. Passion is one thing, but sometimes these debates/arguments get down to finger-pointing and name-calling.

Gregg, that was exactly my point about the belts slipping off. All we know is it happened, but we don't know any details and it was 3 years ago. I'm sure there is more to the story and we don't even know what has or may have been done to alieviate the problem.

John, your assessment of how the tethers on the HANS pre-load during a crash appears to be spot-on. I was a little skeptical, but earlier this week The Discovery Channel reran the racing safety program and I watched the video of the crash test with the HANS very closely. It went down exactly as you said.

ltc

That is the inside of Ryan Newman's car I believe (based on what I can see from the photo).
If you look closely, you can see an attachment on the rollbar horizontal where the belts terminated. It was developed by Penske to allow for use of a single horizontal tube for belt termination rather than a dual horizontal tube arrangement described in the Greg Fishman PRI thread (referenced earlier).

I was shown the attachment piece designed and fabricated by Penske when I was at HMS (picking up my belts) and tried to describe it in a previous thread, again referenced earlier in a reply to FBB. It would be rotated on the existing horizontal bar until the proper harness termination angles/offset was achieved, then welded 180deg around to the bar. The belts (1 2" and 1 3") would then be terminated to this mount. The same process would be repeated for the other side shoulder belts.

Gregg,
I believe you are correct. Coulthard suggested the idea when the HANS became mandatory; IIRC, he was a member of the GP Driver Association safety committee.....I think Schuey is as well.

From what I read, all F1 driver's HANS devices are custom made by Hubbard/Downing to driver/team specifications and the belts are custom made as well. (this is similar to the arrangement Penske has for Ryan Newman).

Personal observation:
As an engineer (amongst other things), I can see no other reason for the return (they were on initial patent drawings and very early devices) of the HANS 'wings' other than to assist in keeping the HANS device UNDER the shoulder belts.
This is in no way implying any weakness or defect in the previous/current HANS devices nor evidence of a smoking gun uncovered during closed sled tests; it is simply an observation based on the addition of a specific feature to an existing design.

fatbillybob

Thanks for the link to the 2" lapbelt thread. Just when you start to think you know what is going on there is a new issue of 2" vs 3" lap belts and pelvis control. Safety is one hell of a moving target! I want to thank GBaker for coming on this forum frequently to tell us about biomechanics as he sees it from a real P.E. in this industry. He lets the engineering chips fall as they may. It is amazing to me that HANS is conspicuously silent. It would be interesting to hear their engineering point of view on the topics raised here. But then perhaps a holy war would erupt. Thanks GBaker to sticking your neck out to save ours and teach us few things to what sits on our necks.

That 2" over belt on the unavailable Schroth harness is really cool. But once that is done I don't see that as a quick get away anymore than the quick release pins on the Isaac. In fact, even if there is a quick release on the 2" over strap the things are still 1+ foot long to tangle you on the way out. These belts sound like a great improvement to a known or perceived problem but now potentially add a new exit problem perhaps? We shall see if those belts make it to the low level club racer. It is getting pretty hard to get out of a racecar these days...left right side nets with quick release, window net with quick release, water tube, cool suit, 6 point harness, 2 new HANS straps?or 2 Isaac quick realease pins, quick release steering wheel, and navigate around my full containment seat head wings. Now just add in a bent rollcage and a door that doesn't open and a fire... Gee...I hope I don't forget anything when I try to get out! Remember when Earnhart Jr. was trying to get out of the burning corvette? That took forever and he and the car were unhurt.

Geo

FBB, I don't think Hubbard-Downing is silent. I think they are interacting at a whole different level besides a bunch of amateur racers.

I agree with you about the over belt vs. the Isaac QR.

I also agree with you about getting out of a race car these days. I sat in a full containment seat at Hubbard-Downing. Didn't think I would fit (fat *** don't you know), but I leaned in sideways and suddenly I was not only in the seat, but extremely comfortably so. Just sitting in their offices it was a bit of a bear getting out. I'm sure if I were on fire I'd be a little more motivated, but it was tough enough to worry me. It would be great for driving though.

RedlineMan

I can think of another one. Perception. It is a POWERFUL thing. Golden if it's with you, dreaded if against. If the general populace perceives the HANS as a device that will not stay under the belts, it would be very hard to turn such a tide back in your favor, even if it was not the case. I'd wager it is a bit of both. The wings can't hurt either the perception OR the reality, I suppose.

Another point to take into account. Many of the sled tests clips that you will see are done with seats that have virtually NO side boltering at all, as if the testers wanted to get a worst or simplest case scenario. A baseline. Then, some of the later tests are done with the massive ISP seat (or similar) that are almost beyond full containment. This certainly must be a mitigating factor, and make A/B comparisons impossible.

I must admit that I have taken pause with how my belts sit on my HANS, and that I wish I had the wings on mine.