FIA Safety Superiority? Not so fast....

Mopar 151w2
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FIA Safety Superiority? Not so fast....

Post by Mopar 151w2 »

I keep hearing the FIA safety standards held up as far superior to their US equivalents, because homogolated!! :roll: , or "they're sled tested". The American approach to safety equipment is different - at least in part because the American side is driven by entrepenurial manufacturers, many of who were seeking an advantage for themselves in their own racing Case in point: Randy Lajoie was a kid working on his Dad's and Grandfathers Modifieds that raced at the Danbury (Ct.) Racarena. They went to a car show in Hartford, and Mark Donahue was there with his Trans Am car. In talking with Mark, they were invited to test sit Mark's signature seat design, and adopted it immediately - as did several other Modified teams.
Now that Randy Lajoie is a seat manufacturer, he proclams his seats are tested on "real tracks, with real drivers", not on test rigs. His point should be well taken, because he was plenty brave as a driver - like this 1984 Daytona Speedweeks wreck!

Joie of Seating evolved as a business because Randy did not want to give up his favorite seat - when fiberglass seats were banned, He began to fabricate the equivalent form of seat in Aluminium, and evolved a system for measuring the driver and transferring that to the multiple aluminium stampings which are welded together to custom size ezch seat.
Yet, I'm told that these would not pass tech for Rally America, as they are not FIA approved. Not Invented Here, indeed..... :evil:
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walterclark
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Re: FIA Safety Superiority? Not so fast....

Post by walterclark »

The part of the FIA regulations pertaining to cages is excellent in my opinion. But not because, as John put it, cages are homologated, but because most of App J Article 253 is devoted to how to fabricate a cage that will not be homologated and what is accepted as fabricated.

Homologated FIA cages are specifically engineered for a particular vehicle by a company that then submits the design and testing to the FIA for approval. Once approved the cage must then be built exactly as specified in the homologation papers, by a constructor that is approved by the company to ensure the cage is as was engineered down to the quality of the welds. The reasoning for all this is that most homologated cages are 1) made from rather thin seamless tubing alloy called T45 that (as I understand it) is similar to chro-moly in terms of strength - and the cage manufacturer is responsible for traceability of the materials which (again as I understand it) are specifically manufactured for the roll cage manufacturers and not generally available otherwise and 2) not limited to many of the requirements for shaping and bracing required of a non-homologated (fabricated) cage. In theory these things allow the cage to be as strong as an FIA compliant fabricated cage but much lighter.

The FIA fabricated cage covered in App J Art 253 is intended to provide a path for compliance of one-off cages, built by non-approved fabricators. As such the tubing materials for construction is specified: Cold drawn seamless unalloyed carbon steel containing a maximum of 0.3 % of carbon, 1.7 % for manganese and 0.6 % for other elements with a minimum tensile strength of 350 N/mm2 and minimum dimensions of 45 x 2.5 (1.75"x0.095") or 50 x 2.0 (2.0"x0.083") for primary structure elements. This is thicker and easier to weld than the material found in most homologated cages to compensate for the acceptance of reduced quality control over material source and assembly as compared to homologated. The minimum cage structure requirements for main and bracing elements in fabricated cages is intended to deliver a safe structure in a wide variety of vehicles without the requirement for extensive proof of engineering for a given fabricated cage that goes into each homologated design.

The only fly in this ointment that I see is the part calling out Cold drawn seamless exclusively. In the US, where we are located, CDS has been a rare and relatively expensive commodity. To address that, sanctioning bodies such as RA (and in the SCCA pro-rally rules for a few years before RA took over) permit either CDS or the similar or stronger strength but more commonly available (in the US) DOM. In each case still limiting the alloy as above to the low carbon, low alloy steels that form and weld easily and do not need post-work treatments such as annealing.

If I had to guess, tubing made from techniques such as ERW have not been allowed because of the wide range of quality found in this lower cost end of tubing, the need for proper orientation of the seam when bending to minimize loss of strength, and the (probably deliberate) lack of any proof-of requirement regarding traceability or material testing of the tubing used in fabricated cages.
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Mopar 151w2
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Re: FIA Safety Superiority? Not so fast....

Post by Mopar 151w2 »

But we just banned CDS.Yes, we did, as far as anything that is on paper. I am not interested in what somebody said, or what part we're gonna not enforce, if it is not part of the document of record, it does not exist.!
...... Because DOM is NOT SEAMLESS, they are not the same thing. Also, the carbon content spec. is only given as a maximum (.3%), and soupy-soft SAE1003 and 1005 have almost no carbon. DOM tubing made from these alloys is commercially available (as hydraulic tubing and exhaust tubing - often called "aluminium killed" steel), but is only half as strong as ERW 1018 0r 1026 DOM.
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Re: FIA Safety Superiority? Not so fast....

Post by Mopar 151w2 »

This is one of the hardest impacts yet recorded, since crash data recording has come along. The vast majority of the safety equipment in use here has no FIA certs, and this car would not pass the "Mild Steel DOM" rule currently in dispute.

IIRC, the impact reportedly registered ~130G - once thought to be unsurvivable.
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walterclark
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Re: FIA Safety Superiority? Not so fast....

Post by walterclark »

Just for fun. Do you have an online reference to available 1003 or 1006 DOM in the diameter and thickness we require? All I find when doing a search for available DOM in our sizes is 1018 or 1020. Its useful to know what is possible versus what is likely.


While the rewording to DOM may not be the best and final way to state our expectations (which I assume all this is about), I think it is a HUGE improvement over magnetic. For one thing, most cage builders understand DOM means something like 1018 and not "exhaust" tubing since the term DOM has been in pretty widespread use in the cage "conversation" for a good while, where as "magnetic" says all sorts of stuff including most iron water pipe is fine so long as it meets our minimum dimensions. Since we dont have the facilities to determine much beyond dimensions of the material used in an assembled cage, I think the best we can do is tell people what they ought to use based on what is widely available and put the onus on them to choose reasonably with that in mind.
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Mopar 151w2
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Re: FIA Safety Superiority? Not so fast....

Post by Mopar 151w2 »

Here 'y' are https://www.marmonkeystone.com/ecomm/do ... Tubing.pdf

To be more precise: My disagreement with current issues has nothing to do with a desire to keep bad tubing out of cages. NOTHING. The entirety of my animus has to do with doing exactly the wrong thing(s), for many of the wrong reasons, and :? this much of a right one - and many of those reasons have to do with the fanboi excptionalisim accorded FIA atandards in some quarters.

P/S
homogolated (big word! It means to register a specific automobile for international racing. And it’s not even definition day yet!)
I've also heard "approved, with paperwork" - Approved by whom, to what standard, is an entirely relevant question.
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walterclark
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Re: FIA Safety Superiority? Not so fast....

Post by walterclark »

From what I can tell the hydraulic tubing in your link isnt referred to as DOM nor does it reference ASTM A 513 Type 5 (DOM). The "cylinder tubing" in the beginning does.

I made a couple calls to suppliers and told them why I was calling, then asked if they would steer me toward or away from J525 or similar or even 100x tubing when I asked simply for 1.75" .095 DOM. They both said that stuff isnt what I want if I want "DOM" for motorsports, that I wanted 1018 or 1020. So, I would say one has to be deliberate to get the wrong thing if looking for DOM cage material.

Also, while its true that by stating only the max carbon and alloys content in Art 253 it might allow a 100x tube, since these do not meet the 350 N/mm2 requirement stated for minimum tensile strength (the cold rolled 1006 I found is around 330) they would not be suitable (cold rolled 1010 is around 365 and cold rolled 1020 is around 420).
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Mopar 151w2
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Re: FIA Safety Superiority? Not so fast....

Post by Mopar 151w2 »

Look at the ASTM spec. numbers. "Hydraulic cylinder tubing" (ASTM A-513)is the original application for 1026 DOM - older catalogs refer to cylinder tubing, and only incedentally to "drawn over mandrel". ASTM A-513 is a spec for "mechanical tubing", which is primarily structural in nature.

ASTM A-53, A-179, and A-214 are specs. for "hydraulic line", which is the 1005 bendable stuff.

Now, based on current knowledge, we could call out "mechanical tubing meeting commercial standards ASTM A-106, A-513, A-519, and equivalents" , and mention that other structural components - gussets, sheet metal, stock frames and body structure, etc - needs to meet its applicable standards, i.e. must be real metal, not a sandwich of rotten floor, old heating duct, undercoating and tarpaper.
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walterclark
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Re: FIA Safety Superiority? Not so fast....

Post by walterclark »

Mopar 151w2 wrote:i.e. must be real metal, not a sandwich of rotten floor, old heating duct, undercoating and tarpaper.
:lol:

You mean a typical New England car then. I have "inherited" 2 New England second gen GTI's where the floorboards consisted of iron oxide between an outside layer of undercoat and inside layer of soundproofing. The seat rails were held in place with a combination of gravity and petrified soda spills.
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Mopar 151w2
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Re: FIA Safety Superiority? Not so fast....

Post by Mopar 151w2 »

The phrase I remember from stock car days is "No bedrail, angle iron, cast pipe, or junk". Yes, I've thrown a car out of the track because it had a cast plumbing union in the middle of the (bent, 2" pipe)main hoop.

This must be carefully worded, however, so as not to exclude decent Triumph framerails. (If such a thing ever existed) After helping Brian Dennis with some engineering to fix suspension issues on his Spit, I'd be looking for framerail fatuige cracks at the firewall, and any corrosion that has penetrated the surface of the frame.
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