SCCA roll bar rules

Son-in-law wanted to remove a column from basement beam for remodel project. I engineered an alternative, ran calculations, and he had a P.E. review and stamp for $200.

Anyone with CAD with a simulation package, and some knowledge of Strength of Materials could do analysis. Without actual calculations, P.E. may or may not stamp, without running own simulation.

At best, a few hundred dollars; @ $250-$300 / hour, and 3-5 hours of time, $750-$1500, I'd guess.

Jay L. seem about right?

RJS
 
All of the specifications and analyses can be completely negated by faulty welds and attachment to the chassis/tub.
 
Thanks RJ for the report.

Here is the first blush from someone that does Risk Management every day. The report concerns a cage for a STREET CRX vehicle using GT specifications. It would have to be assumed that since the street CRX was measured for cage installation the interior was still in the car. The cage in question was designed by the testing group and met the rule that does not have specific bar placement guidelines. That said the testing body could design the cage within the build characteristics with the intent to fail hoping for an engineering contract. The cage models in the four examples look nothing like the cages I'm familiar with and common to the various classes much less GT. Since the report is GT specific all other classes would be exempt from the determinations of the report.

I've turned the report over to my risk manager and engineering group for analysis of the testing process, not the cage as described. I'll report their findings when they are returned. Personally I see this as windmill jousting but I'll let them tell me otherwise.

Setting standards allows any group to be sued for non compliance or failure to meet perceived safety standards. In court you are always better served to not have overly defined rules and standards. Rules are used to fire employees and sue the company. Both of those reasons are tied to a resultant financial decision. They have little other purpose in a legal or practical sense.

James -r
 
Report states design met GCR then in effect.

As with any engineering calculations, many assumptions had to be made such as welds are as strong as parent tubes, floor mounts are rigid and not potential failure mode, etc. Analysis was for cage design only.

Wished all figures were present in original colored version. Would show all stressed points, degree of stress, and all areas exceeding yield strengths.

Curious SCCA still allows alternate designs for some open cockpit classes, using same stress loads used in this report. Why not allow for roadster Production cars?

RJS
 
Well, I agree that having a safe design is paramount. But if I had to guess as to why go to a single design. I would say to eliminate Prod guys that would build a more aero roll cage. In other words, to level the aerodynamic playing field. Like prod cars don't have enough differences to try and balance. As it is I've seen many prod main hoops that go full width but have nothing to support the hoop in the middle. I bend tubing for a living. I can tell you without reservation that I would not drive many of the prod cars out there. Including my old FP car that had all the strength removed from the hoop in the name of aerodynamics. Prod car guys flirt with disaster when left to there own devices. As the saying goes,"common sense is not so common.
Chris
 
Chris ,

Interesting comments, from them I would conclude you agree with SCCA that the prod drivers are less responsible and less skilled in these matters than the formula and sports racing drivers? And there for need to be supervised more closely?
 
No Rick, you misunderstand me. I think there is a certain percentage of racers that would unknowingly endanger themselves for a performance advantage in all race groups in the SCCA. I've seen it time and again. The roll cage thing is just one of the many places this happens, when allowed. I think the roll cage rules are full of holes as they sit already. I think another problem with having one off cage designs comes down to the drawings a P.E supplies. There usually unreadable. Have had several engineering plans done for home expansions. Looked like a pile of scribbles to me with a pretty and expensive stamp. How does the club police that. It really can't. I think it probably came down to simplifying thing for the tech shed. Your point about the current design is good. Though without the paperwork to show everyone, your kinda just blowing smoke. Please, prove me wrong.
Chris
 
Chris,
I think it was fair to take it as I did because your statement was very specific to prod drivers
"I can tell you without reservation that I would not drive many of the prod cars out there. Including my old FP car that had all the strength removed from the hoop in the name of aerodynamics. Prod car guys flirt with disaster when left to there own devices. As the saying goes,"common sense is not so common."
Then it must fair to conclude you would remove the alt cage option from all SCCA class's? And require a SCCA design on every one? Personally I think that would compound the problem for the club. Your statement " How does the club police that. It really can't" is the point, the club should not be setting it self up as an expert on roll cages when they have proved they aren't. As to a PE report being unreadable, just because you don't , or myself either, understand them does not make then any less valid, hopefully one would be the basis of any design SCCA would require. Which they tried to do and failed at and now we are back where I started. SCCA has no proven expertise in this field and I think I can do better. The bigger problem is beyond whether the SCCA design can pass or fail an engineering test. it traps a driver in a inverted car and forces a driver to have unnecessary bars around his head. Those 2 things alone are enough for me to reject it.

I have not seen a E-mail from you requesting copies of some of the information I have? I did not copy the whole Altair report because as you said most of it is of no use but the 3 page letter from Jim Leithauser to the BOD/CRB tells the story.

[email protected]
 
All race cars are just a giant rolling compromise.

From looking at Rick's car, I'd be worried about another car or a tire barrier ending up on my head.

From the typical open prod cage, I'd be worried about entrapment if you were upside down.

Of course you could go with a high front hoop cage. But you'd be compromising aero and CG further.

Compromises ..... shades of grey .....

There is no simple answer.

-Kyle
 
Kyle
I would disagree, there is simple answer, The reinstatement of an alterative roll bar rule. Have a rule set that allows you to evaluate the options and compromises and build what is best for you. This being the same for each driver and much reduced liability for SCCA too. Nothing in a alt. bar rule would force anyone to race with my design or any one else's, but most important no one would be required to run the SCCA bar with it acknowledged faults. My preferred design has nothing to do with this , you may not feel safe in it. It has been tested under the same criteria that the SCCA bar failed ,but no one would be required to use it under a alt. bar rule. Your post sounds like you see this as either/or situation when it is really about having a wider range of options in the matter. It really does not need to be as complicated as many are making it..
 
How about....
Build cage to standard "c" + 60 lbs or 4% or whatever.
Build cage to standard "b" + 30 lbs
Build cage to safest standard "a" no weight added :mrgreen:

Bet our cars would get safer :mrgreen:
Just having fun.
 
Got a copy of the full report. There was no in car failure. The cage mentioned in the previously mentioned report was tested outside of the car and bolted to a table. This is not an issue that even needs discussion.

James -r
 
James,

I read your post several times looking for a hidden insightful meaning and then realized you meant exactly what you said.
I really have no Idea how to reply to such a ridiculous comment.
 
I intend on submitting a formal request for the alternative roll bar rule to be reinstated in the GCR. All the comments that were posted on this subject were very helpful in my deciding to do this. While there were certainly some people who disagreed with my position, none of these were able to offer any credible reasons why production cars should not have the same privilege and access to an alternative bar that SCCA provides to sports racers and formula cars. If you agree with my position, and would like the possible future alternative of building a safer roll cage in any new car you might build, please contact the ad hoc and the CRB.

rick haynes
 
The final report that Rick keeps bringing up states that the cage was tested NOT IN A CAR. The test was worthless.

James -r
 
I am sure most people know this, but for James information

Finite Element Analysis is:

"Finite element analysis (FEA) is a computerized method for predicting how a product reacts to real-world forces, vibration, heat, fluid flow, and other physical effects. Finite element analysis shows whether a product will break, wear out, or work the way it was designed. It is called analysis, but in the product development process, it is used to predict what is going to happen when the product is used."

Using FEA you don't have to build it to find out it doesn't meet the required specifications [ SCCAs in this case] and you can find out if a new design [mind in this case] does meet the required specifications. Which it does.

What is the better alternative, James? Build it and then drive it in to a wall?
 
I understand and share Rick's sentiments in a big way. However, the pessimist in me says be careful what you wish for. Having to present a finite element analysis for, and/or have a certified engineering study done on every single roll cage you want to run in production could also be the result of a request like this. Personally I would rather build a cage to the SCCA spec, even if it was not exactly what I wanted, than be burdened with a bunch of difficult, time consuming, and expensive stuff like that. Look at what the Europeans have to do, yuck. They can buy expensive certified cages for the common stuff, or really, really expensive certified custom cages for the less common stuff. Maybe being able to build our own stuff is something we should appreciate??
 
Curtis,
Please keep in mind the addition of an alternation bar option in the GCR would not keep any one from building a cage to the SCCA preferred design. It would just allow those people who don't like the SCCA cage to design there own. And I have no problem with a provision that requires that new design past a set of performance criteria. The problem has always been that the SCCA design does not.
 
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