Change in horse collar rule....but what are they looking for?

[Stainless1]

We have that tight fit thing working for us, seemed to be more room in the car 10 years ago... 

[RichFox]

Actually, I think my car has become to tight for me. All things considered I have pretty much decided that someone else would be a better choice for driver. A twenty second bail out would not be a pretty sight.

[hotrod]

Here are a couple more links that might prove interesting reading

http://www.nhra.com/content/news/19654.htm

http://www.nhra.com/content/news/19614.htm

It is interesting to note that John Force mentions that you can have the padding too close to the drivers head too! If there is not enough free space vibrations can be transmitted to the drivers head and result in blurred vision.

So far I have not found any links that mention a "recommended spacing" per John Force's test runs.

Although the pictures in the first link are helpful in that an estimate can be made.

Anyone have any direct connections to the NHRA tech folks to get better info regarding what adjustments he made that eliminated vision blurring?

The other question would be if the crash event like a blown tire or partial dissassembly of a wheel at speed, results in high G lateral accelerations, should the drivers head wings have a means to dampen vibrations so the drivers head does not simply become a ping pong ball vibrating between the pads. If the padding assembly absorbs energy with a friction damper on each impact you would prevent build up of energy into a resonance condition where the drivers head vibration rate might sync up with the natural frequency of vibration (rebound speed) of the padding. Conventional roll bar padding is designed to dissipate energy in a more or less single impact not a repeated series of harmonic impacts.

Here is a link to the manufacturer he used for his seats.
http://www.ispseats.com/gpage3.html

Looks like there is an SFI spec 45.2 for lateral restraints.

Larry

[Sumner]

.................................It is interesting to note that John Force mentions that you can have the padding too close to the drivers head too! If there is not enough free space vibrations can be transmitted to the drivers head and result in blurred vision................

Tom addressed that in the link I posted.  That has also been a problem when the salt is bad for most of the cars without suspension and some with suspension.

c ya,

Sum

[Carl Johansson]

First off all -  by rule (3.B.2) any place on the roll bar that could come in contact with the helmet needs to be padded with SFI 45.1 padding.  But I assume an earflap is not the roll bar -  so it is not required to have padding!  But that would be up to an inspector to make a call on it!

Second of all I can't envision your setup - where ear flaps would allow you easier access than another bar - 
look at my photos   Where those 2 vert bars come down on either side of the drivers heads -  originally the ear flaps were there -  and the extended 4 or 5 inches forward of those bars -  it was a real hazzard trying to clear your helmet from around those flaps.   Changing to padded tubing actually gave me more room -  better visability and easier faster exits and entries.

I put in both of those bars after I removed the ear flaps - 

Carl

Carl I too am not happy about the kirkey earflaps. I have a buddy that races Mazda SCCA cars and I thought they were tits until he told me that they take the stock ones and weld new braces to the sides to give them a little strength. After seeing the stock ones I can see why they need to be beefed up.....he said I would be better off making my own.


------------------BUT-----------------------


I do not have the room to make loops out of the same bar as the cage.
I am already pushing the limits of being able to get in and more importantly, out.

I can make kirkey style flaps.....and have already started but I am using 1/2" solid bar (bent into a "U" with a bar that attaches to the middle....sort of like a pitch fork and capping it with .095 sheet on one side. They would extend to where the visor starts to retain vison.

I did not plan on having the lat support have padding......and the kirkey slip covers should not be considered padding ether.

So is tech going to say about my earflaps and no padding?

[hotrod]

It is interesting to note that John Force mentions that you can have the padding too close to the drivers head too!

Tom addressed that in the link I posted.

I noticed that but he mentioned a space of 1/4 inch and John Forces setup appears to have in excess of 1 inch, which was why I was wondering about concrete info on the spacing used during the tests John Force did. Part of it of course would be that the spacing required would be driven by the normal level of operational vibrations and their average direction. Tire shake on a funny car is I presume a bit more violent and of higher magnitude than the vibrations from running on a rough surface at speed.

It may be one of those things that you set it as tight as you can with out getting vibration coupling to the helmet. It would be interesting to see the before and after spacing John used in his tests.

Larry

[Jonny Hotnuts]

Carl our cages are similar but I was told by an official that the lateral support bars needed to be something like 8" in from the back of the head rest. (dont know if this is true but I was told it had to be something like this:



 


I was also originally told that the kirkey earflaps were the way to go....it is now clearly the general consensus that they are not.

Seems odd that they would require a tube as heavy as the roll cage to support lateral movement of a 13 pound head. I have not run a calculaton yet but I think a 13 pound head would need to be traveling around 850 mph to make any bend in a 2' bar that is 1 5/8X .120. I am already working on trying a setup like yours but having to use roll cage legal bars is really limiting what I can do.

[Sumner]

...............Seems odd that they would require a tube as heavy as the roll cage to support lateral movement of a 13 pound head...................

Where do you see that they require "a tube as heavy as the roll cage"

3.A.3 Driver's Helmet Support:
A helmet support shall be in all vehicles.

  Forward movem...........talks about "encouragement" of use of a HANS  type device.................

(then)

Lateral movement:  The structure shall provide................

It does not describe or specify what the structure has to be made of.  At least the way I read it.

c ya,

Sum

[Carl Johansson]

Carl our cages are similar but I was told by an official that the lateral support bars needed to be something like 8" in from the back of the head rest.
I was also originally told that the kirkey earflaps were the way to go....it is now clearly the general consensus that they are not.

Seems odd that they would require a tube as heavy as the roll cage to support lateral movement of a 13 pound head. I have not run a calculaton yet but I think a 13 pound head would need to be traveling around 850 mph to make any bend in a 2' bar that is 1 5/8X .120. I am already working on trying a setup like yours but having to use roll cage legal bars is really limiting what I can do.

I heard nothing about 8 inches in, different inspectors different viewpoints I guess.  As for the size of the bars -  i used tubing because I had the space -  and it strengthened the cage as well -  more protection from crushdown.  If all I was interested in was holding the helmet in place I would have done it with much smaller tubing -  or bar stock.
Your gunna get all sorts of opinions and ideas here and from the inspectors.  You need to make sure you have considered their input -  but it's your head on the line -  do it so you are comfortable (not physically -  just sure you will be safe) with the setup protecting you!  Get your inspection sticker and be done with it!

Also i AM SEEING TRIANGULAR SHAPED NETTING RUNNING ALONG THE INSIDE OF THE DRIVERS HELMET IN SOME NASCAR SETUPS -  i ASSUME THAT IS THERE TO LIMIT LATERAL HEAD MOVEMENT (not yelling -  just a typo error)

Carl
Carl

[Jonny Hotnuts]

Where do you see that they require "a tube as heavy as the roll cage"

3.A.3 Driver's Helmet Support:
A helmet support shall be in all vehicles.

  Forward movem...........talks about "encouragement" of use of a HANS  type device.................

(then)

Lateral movement:  The structure shall provide................

It does not describe or specify what the structure has to be made of.  At least the way I read it.

c ya,

It is because of the words "the structure" in 3.A.3, THEN says "see section 3.B.1" and in the first line of 3.B.1 says "minimum requirements for the roll cage structure."

There is no mention of anything for the lateral head movement requirements in 3.B.1 so "the structure" in 3.A.3 has to be the same and requires a minimum of 1 5/8 OD.

I might be crazy and over thinking this.


Carl......stop yelling.

[Sumner]

................I might be crazy and over thinking this......

I tend to do that and think you are here.  Yes the roll cage is the structure that they want around your head, but they also allow you to use that piece of "one inch wide and minimum .125 inches thick (strap), mild steel and welded inside the roll cage to prevent the driver helmet from exiting the roll cage between the bar. See figure 4 (p.24)".

So now we have a roll cage around the head and if the roll cage tubing is too far apart we have added a strap to the inside.  At this point I feel you have meet the safety requirements for the cage itself in the head area.  If you now want to or need to add adjustable "padded" bars/straps inside of that area to limit the lateral head movement "I feel" they are leaving it up to you to design those and as long as they look reasonable I would feel they would pass tech.  My feelings and what I'll be doing.

c ya,

Sum

[Bob Drury]

Rich, in the last three years we have gone from having only two types of head restraints, the Hans and the Hutchens device, to having around six or seven different brand devices, all improvements over what we had five years ago.  This is a industry that has blossomed with the help of computer animation and physiological profiles unknown in the past.  Just remember, anything is better than nothing, and NO ONE PERSON or persons has the knowledge to tell you which one is the best.  Unfortunately, the better ones are all priced around a grand apiece, but with a little ingenuity, even a home built is better than no restaints at all.  I am currently using a G Force lateral restraint (about $300.) with two side tethers (ala sprint car) at around $25. a piece.  The "post Hans" type are a little more user friendly if you need a fast exit, as they don't stick up as high and are less likely to hang up on the roll cage when baling out with your ass on fire..............

[Roadster943]

    Am I reading the rule book wrong? I see the difference this year to be that the helmet support shall be used in all vehicles as opposed to last year shall be used in vehicles where the roll cage structure does not provide restriction to lateral head movement of less than 4 inches.  I read it to say that the neck collar is legal this year.  I was hoping to talk to people and look at what they are using this year. I am leaning towards the HANS but I need to make sure that I can get my 6' 5" out of the roadster before I spend that kind of money. Am I wrong thinking  the neck collar is going to be legal at Speedweek?   Thanks Vince

[Sumner]

    Am I reading the rule book wrong? I see the difference this year to be that the helmet support shall be used in all vehicles as opposed to last year shall be used in vehicles where the roll cage structure does not provide restriction to lateral head movement of less than 4 inches.  I read it to say that the neck collar is legal this year.  I was hoping to talk to people and look at what they are using this year. I am leaning towards the HANS but I need to make sure that I can get my 6' 5" out of the roadster before I spend that kind of money. Am I wrong thinking  the neck collar is going to be legal at Speedweek?   Thanks Vince

Prior to this year, neck collar "required .....when roll bar structure does not provide restriction to lateral head movement of less than 4 inches". 

This year, the roll cage "structure shall provide restriction to lateral head movement of less than 2" per side".  I don't see where you are prohibited in wearing a neck collar if you so desire, it just can't be used to meet the helmet support rule anymore. 

I also feel if your roll bar is more than 2 inches from your helmet on each side you don't have to cut it off and move it in you can add on to the inside of that "structure" to meet the requirement of the rule, but no one seems to want to clarify that officially here so you might want to e-mail, call or write the appropriate person.

c ya,

Sum

[Jonny Hotnuts]

I was told by an official that the horse collar was causing injures....or was not affective in preventing injures and they were going to do away with them.


I dont think they will be legal this year.....could be wrong,....Im not taking chances!