Fuel Cell Container Thickness?

[Craig Henry]

Per the 2008 GCR:

9.3.26. FUEL CELL SPECIFICATIONS

2. Container

b. Sports Racing Category and Formula Cars
The fuel bladder shall be completely surrounded by a container (which may also be a part of the structure or bodywork of the car) to ensure rigid and secure mounting of the bladder and provide additional protection. A minimum of .036 inch steel, .059 inch aluminum, or an approved equivalent is required for all vehicles.

-----------------------------------

I grabbed a micrometer out of the toolbox last night and measured the very thin stock aluminum cover on my RF92 FF. As I suspected, it was about 0.032” or so thick. It seemed to be soft (5052H32?) because I could easily bend it with my fingers. Also, the bulkhead was only about 0.045” thick. How could the car pass the homologation process is the container / bulkhead are both out of spec.? My old S2 cell's container (the tub) was in the same boat - 0.050” including the floor pan it was sitting on (much thinner in reality as it was well worn.)

Did Van Diemen somehow get around the rules or am I missing something.

Craig

[Charles Warner]

Per the 2008 GCR:

9.3.26. FUEL CELL SPECIFICATIONS

A minimum of .036 inch steel, .059 inch aluminum, or an approved equivalent is required for all vehicles.

What were the required specs the year the car was homologated? I would say these would be the specs to which the car should be judged and would fall under the "approved equivalent" comment.

[R. Pare]

What the specs were at the time of homologation is irrelevant for what the cars have to be at this point in time. Sometime in the early '90's, the rules were changed to require a .059" minimum surround on the cell, and ALL cars, including Club Fords, had to be brought up to spec.

Looks like the previous owner(s) ignored the requirement, and it was never checked by Tech.

[Brian]

when you order material to make up your new cover, be aware that 16 Ga aluminium sheet is .059", and if you want .065" for cockpit sides or whatever, you have to ask for 14 Ga. I only point this out because it's different from the sizes for steel steel.

Every time I get an older car in my shop, I have to make new fuel cell covers. It's like no one checks, ever.

Brian

[rickb99]

Well, I'm certainly glad this came up now. I'm guessing that our 89 Reynard cell enclosure is too thin. This will solve the problem we were pondering which was, if we buy a 4x8 sheet to redo the belly pan, what are we gonna do with all the extra material? Problem solved if we get the right gauge.

[Charles Warner]

What the specs were at the time of homologation is irrelevant for what the cars have to be at this point in time. Sometime in the early '90's, the rules were changed to require a .059" minimum surround on the cell, and ALL cars, including Club Fords, had to be brought up to spec.

Richard,

Is it stated anywhere that a car's homologation papers are superceded by a statement in the GCR particular to fuel cell enclosures? If so, then the homologation papers required to be available with the logbook would be worth little without attachments showing the adherence to all future required mods.

I would imagine this issue would affect the VAST majority of tub cars in existence (excluding carbon cars.) In the case of the Lola S2 it would require complete re-tubbing of the fuel cell, bottom, and rear bulkhead area. I assume almost all tub cars would be so affected. IF this is indeed the Club position then a lot of racers will be in need of major tub mods. Obviously clarification is needed from the Club. Stan?

[R. Pare]

Charles:

No, there is not specific statement about fuel cell enclosures of the type you ask about. There IS, however, the requirement that all cars comply with whatever the current specs are. Look at GCR 9.1.

As stated before, homologation papers only state that the car complied to the rules in effect at the time of issuance. Any subsequent changes in the GCR do not effect the homologation papers at all - ie - those papers do not need to be changed. However, ALL cars have to meet current GCR specs. Annual tech inspection is done to the current year GCR requirements, not to what the requirements were the year before, or 20 years ago, or whenever the car was homologated.

For cars with thinner-than-currently-required enclosures, all that need be done is to add in secondary panels to upgrade the overall thickness to at least the minimum requirements - the rules only state overall thickness, with no mention of a limit as to the number of layers used to reach that limit. Complete re-tubbing, etc, is not required.

[Charles Warner]

Richard,

I fear we are entering into an interpretive area here as nothing is clearly put down in writing regarding the continuing updating of required specs as they apply to previously homologated vehicles. It could be posited that the "approved equivalent" statement refers to the homologation specs at the time of issue.

"Annual tech inspection is done to the current year GCR requirements, not to what the requirements were the year before, or 20 years ago, or whenever the car was homologated."

So, 19 years (Lola 89/90) of continued techs/annual techs, supposedly to "current year GCR requirements," goes for naught? Precedence, it might seem, has been set.


In any event, I have never heard of any chassis being tested for this issue by event tech inspectors.

[R. Pare]

Charles:

I truely do not understand your reasoning for your worry (if it is a worry).

As per the GCR, ALL cars have to meet whatever the current GCR specifications are, regardless of when the car was made and homologated. This have been Club Law pretty much since the inception of the club, and is stated explicitly at the start of just about every set of class rules, as well as in section 9. Just because a car was homologated 20 years ago does not mean that it can escape complying to the current specifications.

As stated at the start of the Formula Car Specifications:

GCR - 175
9.1.1. Formula Car Category Specifications
FCS
9.1.1. FORMULA CATEGORY
These specifications are part of the SCCA General Competition Rules (GCR) and all automobiles shall conform with GCR Section 9.

The Formula Category is intended to provide the membership and interested
manufacturers with the opportunity to compete in purpose built, highly modified open wheel single seat cars. The Club may alter or adjust specifications and require, permit, or restrict certain specific components to equate competitive potential.

At the start of Section 9 :

GCR - 73
9. Cars and Equipment
General
9. CARS AND EQUIPMENT

9.1. CATEGORIES AND CLASSES
Descriptions of the automobiles eligible to compete in the various SCCA Club Racing competition events are carried in the GCR and category specification books. Their amendments and clarifications are published in FasTrack and on the Official SCCA web site.

To compete in an SCCA sanctioned event, all cars shall comply with the requirements of the GCR and of the specifications for their category and class. If these General Provisions and Specific Provisions for a category/class shall conflict, the specific category/class provisions shall take precedence. In cases where the specification line for a particular car conflicts with the class/category rules the spec line shall have precedence.



Again : getting a car homologated solely means that the manufacturer has submitted the car for approval that it complies to the safety requirements in effect at the time of that submittal, and that he recieved that approval. Compliance to rules changes as the years go by is the responsibility of the owner. Checking that the car has been upgraded to any new specifications is the responsibility of Tech.

Not sure what else I can say!

[Charles Warner]

I'm sure you are right, Richard.

[R. Pare]

The homologation process has caused a lot of confusion over the years. Up until it was changed 10 years or so ago, "homologation", as stated in the GCR, was not limited to safety items - quite a few construction items were covered also.

This brought up some confusion as to whether or not a particular design feature that had passed the homologation process could be later ruled illegal without a rules change specifically outlawing that feature ( I even posed this question to the CRB a couple of times). The homologation process was then changed ("clarified") to cover safety items only. I don't see that specific language in the current GCR, so that may have changed again and I didn't catch it, or I'm just looking in the wrong place.

Your concerns seem to point towards the oft-used saying by those whose car is protested at some point "Well, it has passed Tech for the last XXX years!".

Unfortunately, the inspectors don't always remember to check for certain items after a rules change - they may remember to check during that particular season, but forget about it the next because they maybe assume that it was checked off the previous year ( forgetting that the car sat idle for that season, or whatever).

A couple of examples of already-homologated cars having to upgrade because of rules changes:

1 - Dash hoops. Dash hoop requirements were upgraded maybe 15 years ago. Just about every Club Ford had to either get one installed (if they didn't have one at all), or had to change to the new, larger diameter specification. We installed new 1 3/8" hoops on a lot of our old Club cars, and every one of them had to be teched on it before a sticker was issued.

2 - This same fuel cell surround as we are now talking about. We had to do the same as with the hoop issue - upgrade our customers older cars, including Club Fords. Again, Tech specifically looked for that upgrade when the cars were teched before the next race.

There are (probably) hundreds more.

I would suggest that everyone double-check their cars for any compliance issues like this that may have been overlooked for years - better to get it fixed in the off season than not be allowed to run at your first race next year!

[J Leonard]

If your log book is running out of pages and you need another one issued. Thats when they really start looking at all the above items.

[Larry]

Homologation reflects the rules in effect when the certificate was issued. The homologation certificate (and an SCCA logbook) are absolutely NO GUARANTEE that the car is legal! Nor is the logbook any guarantee that car damage has been recorded, since many non-SCCA events take place, and there is no requirement to provide an SCCA logbook at them.

There are some thorough tech inspectors, and some lax ones...some rigorous regions and some lax ones. Your best bet is to tech your own car, step-by-step, following the GCR and recording your measurements. This includes roll hoop measurement (especially wall thickness), belly pan, side structure, fuel cell, etc. An SCCA tech inspection is absolutely no guarantee of anything other than the fact that it met the minimum standard for whoever inspected the car on that particular day.

Larry Oliver
International Racing Products

[Craig Henry]

Thanks everyone. New stock for the replacement cover and bulkhead was shipped out today.

Craig

[Craig Henry]

Is the fuel cell surround considered a “stress bearing panel” thus exempt from the 6” fastener rule? It’s not specifically called out in the “exempt” section. Just verifying before I space the rivet pattern.

Thanks in advance for the help.

Craig

[Brian]

I don't consider it a panel, from that perspective, and I install them as I see fit.
Brian

[R. Pare]

Is the fuel cell surround considered a “stress bearing panel” thus exempt from the 6” fastener rule? Craig

It depends on just how it is attached to the frame. If a given panel is attached to only one rail,and has fasteners closer than 6" on centers, it technically meets the written description of what constitutes a "stressed panel", but the fact that it isn't transfering loads to other rails would probably allow you to argue that it is not performing the function that normally a stressed panel does.