2007 GCR Roll Cage rules

[JoshS]

So my car is getting its cage as we speak, but I took a look at the 2007 GCR just to confirm that nothing changed unexpectedly. It appears something has, but then evidence says it hasn't. Let's see what the peanut gallery thinks.

The diagram in the 2007 GCR showing the SS/IT roll cage is at very low resolution and the text is not readable (figure 8 on page GCR-91).
http://members.roadfly.com/jsirota/Z3Coupe/cage-07.jpg

The equivalent diagram in the 2006 GCR (figure 1 on page GCR-105) has the text "Improved Touring diagonal: Tube A-D or B-C is required."
http://members.roadfly.com/jsirota/Z3Coupe/cage-06.jpg

In the 2007 diagram, although I cannot make out the text entirely, it looks like this has changed. It appears to say "IMPROVED TOURING DIAGONAL A-D, B-C, A-??? or B-???". I can only imagine that it's supposed to say A-F or B-E, but this doesn't make much sense.

I sent a note to Jeremy Thoennes at the SCCA, who assured me that nothing has changed for '07. So what do you all think this diagram is trying to say?

[Z3_GoCar]

Hey Josh,

The reference you're giving refers to the main-hoop diagonal brace, Since we drive from the left side you want it to slant from the top-left to bottom-right. The variation comes in for those strange cars built with the driver on the other side of the car. The only issue I can see with the drawing is it doesn't refer to the mandatory two door bars per side. This is where the confusion has set in, does a X-shapped door bar qualify as two door bars when there are three actual bars and a point when there's only one bar? The answer is it's considered to be equvalient. Still two bars that run similar to NASCAR style will give better protection but aren't quite as stiff for the weight.

James

[Greg Amy]

Boy, that sure is crappy resolution...

Josh, if Jeremy says that nothing changed, then he'll need to have that diagram changed under Errors and Omissions. However, if he's incorrect (and remember: his opinion does not carry the "rule of law") then it may have been intended to make it read, "Improved Touring diagonal: Tube A-D, B-C, B-E, or A-F is required."

I've generally got a problem with the new GCR in that it's been changed substatially, in terms of format; that will create a lot of confusion. In addition, there's a lot of items in there that are not covered by published Fastracks; who's to say there's a lot of other mistakes that we won't catch? Used to be where you could knowe the GCR once, then get updated via Fastracks as time went on. Seems now it's time to snuggle into a warm bed and read the whole damn thing again...



...does a X-shapped door bar qualify as two door bars when there are three actual bars and a point when there's only one bar?[/b]

Topeka has ruled that this *is* a legal application of the new door bar rules; I received the notice via our regional and divisional tech stewards. I understand a Fastrack clarification is forthcoming.

Greg

[gsbaker]

...However, if he's incorrect (and remember: his opinion does not carry the "rule of law") then it may have been intended to make it read, "Improved Touring diagonal: Tube A-D, B-C, B-E, or A-F is required."[/b]
That makes sense, structurally. You're being given an option. The graphics are horrid, though.

[JoshS]

What's disappointing about this, as Greg pointed out, is that this potentially new cage allowance is a rule change that is really untrackable unless someone compares the two GCRs. And comparing the two GCRs is very difficult since everything is renumbered and relocated.

The 2006 GCR had wording defining this main hoop diagonal in the ITCS (page ITCS-14, paragraph 5: "A lateral, diagonal main hoop brace illustrated in Figure 1, GCR Section 18., is required."). For 2007, that line has been removed from that paragraph (now paragraph 3, BTW). No change bars. So if one were looking at that part of the rules, one would assume that no diagonal brace is required at all any longer.

But then we look at the roll cage rules (used to be chapter 18, now it's chapter 9.4). There are no change bars anywhere, although everything has been renumbered. I can't find any wording changes, so we're left with the wording from 2006: "[The main roll hoop] shall incorporate a diagonal lateral brace to prevent lateral distortion of the hoop (See Figure 1)." Sure sounds like A-D or B-C is still required. In fact, it talks about it being mandatory for the harness bar to continue across the diagonal to the opposite side of the main hoop, which wouldn't make sense for an B-E or A-F option.

BTW, BMWCCA uses NASA cage rules apparently, and they require B-C. No options. Because I want this car to be legal there (mostly for resale value), I'm choosing that option.

Seems like someone changed this diagram without thinking about any of the text. I wonder if it's really intentional to allow a difference between IT and SS cages. Why not make the IT/SS rules the same?

Alright, I'm done venting.

[Greg Amy]

Alright, I'm done venting.
[/b]

Trust me, we've all been there. I would LOVE to be the chairman of a committee devoted solely to overhauling the rollcage rules for the SCCA. I mean starting from scratch and making everything make sense.

But, it ain't gonna happen...

[HONDA69]

Did anyone else see the Miata that was crashed into on the passenger side during the Enduro - Door bars were hanging loosely close to the shifter!! Bars were intact, as they failed at the welds, or just past the welds. Note this was based on a visual inspection only!! :( Moral to this story - Check the welding done on your cage!!

[ddewhurst]

I' starten over below with a new post. :024:

[Z3_GoCar]

In my humble educational experience in engineering & in my humble observational judgement when fabricating a roll cage with the required main hoop diagonal (at the get go required to gain maximum driver protection) any diagonal except the B-C diagonal IS NOT providing MAXIMUM driver protection.

This whole bunch of BS main hoop diagonal
[/b]

Unless you sit on the Other side :) of the car then the A-D style makes more sense.

James

[Greg Amy]

David, you drinkin' again? Or do you want to try writing that again...?

;)

[ddewhurst]

Greg, first off congrtas on your ARRC victory. :smilie_pokal: Great job driver. ;) I got so frustrated reading this crap about the re-write of the GCR/roll cages that I went to watch My name is Earl on the tube. Earl's list makes more sence that the re-written GCR/roll cages. No I ain't had a thing to drink in some time. Matbe that's the issue.

James, any car with the driver on the right hand side should/SHALL have the main hoop diagonal A-D. ;)

Now back to finish my original RANT of fact with my original post. Oh screw it, I'll do a new post. I'm tellen ya guys I'm realy going to RANT & ROLL. This re-write of the GCR/roll cage main hoop diagonal is nothing more than a copy of the Production car main hoop diagonal which was bastardized to please some of the Production car owners who made their own rules by strain & torture of the original written Production car roll cage rules.

Have Fun ;)
David

[ddewhurst]

Greg A. quote:

***...However, if he's incorrect (and remember: his opinion does not carry the "rule of law") then it may have been intended to make it read, "Improved Touring diagonal: Tube A-D, B-C, B-E, or A-F is required."***

Greg B. quote:

***That makes sense, structurally. You're being given an option. The graphics are horrid, though.***

I went & looked at the 2007 GCR/SS/IT roll cage rules & the friken picture with the main hoop diagonal attachment point options is nothing more than a copy of the 2006 GCR Production car roll cage main hoop diagonal attachment options. If the above is what the revised rule spec is in my humble educational experience in engineering & in my humble observational judgement when fabricating a roll cage with the required main hoop diagonal, any diagonal for a left hand driver position except the B-C diagonal IS NOT providing MAXIMUM driver protection. I was/am pissed because in the 2005 GCR/SS/IT the rule was laxed by adding the main hoop diagonal attaching points A-D. If we have IT cars classed with the driver position on the right hand side then give THEM the main hoop diagonal attachment points per A-D. These optional attachment point decisions for the main hoop diagonal are being made by people who don't have a clue. With these 2007 SS/IT main hoop diagonal optional attachment points the rule re-writer is going over the top wher he has no clue towards safety.

Do either of you two Greg's beleive that your personal safety is at it's best with the main hoop diagonal being attached any place other than at point B & point C with your left hand drive cars ? Please don't add a bunch of other tubes in your roll cage. For this conversation let's use the minimal roll cage with a main hoop diagonal from point B to point C including a main hoop horizontal, two rearward braces & the normal minimal side protection & no Petty bar. Lets answer the question when we have the minimal basic roll cage. ;)

This whole bunch of BS with the main hoop diagonal going where ever the hell one wants it to go & the elimination of the main hoop horizontal started with the loose goose Production cars the way those people strain & torture the rules. There are Production cars that race in the North East that the driver suits UNDER the main hoop. There is also a car from area 4 of the CenDiv that races in the North East that the driver sits UNDER the main hoop. Read rule 18.1.2 with respect to a driver sitting under the main hoop & tell me if sitting under the main hoop is legal in a Production car or an IT car. Next a Production car (2nd gen rx-7) from the Rocky Mountain Division attached his main hoop diagonal to the upper left of the main hoop & to the right rear spring perch area.

Now we have a loose goose cannon (called a paid SCCA employee) rewriting the GCR/roll cage rules that IMHJ should be drumed out of the SCCA offices. I could go on about this loose goose cannon & his rule specification understanding at the 2006 Runoffs which was/is ALL wrong. When someone in a position of paid responsibility with the SCCA makes decisions that I can see through my friends, that is BAD.

VENTING, ya dam right I'm venting & it will not stop with this post. I don't piss & moan about a lot of issues but this crap with the main hoop diagonal is beyond words.

With this multiple choices main hoop diagonal location attachment points written into the 2007 GCR/SS/IT roll cage rule it's time for everyone with a brain to write a letter to the President of the SCCA, the BoD & the Director of club racing for someones removal from the SCCA payroll.

If you disagree with any of the points I presented please post your disagreement for review. :) :) ;)

Have Fun ;)
David

[BMW RACER]

Slightly off the thread. In a left hand drive car (are there any right hand drive IT cars?) B-C makes sense, the question I have is: How close does B have to be to the corner of the cage? What I'm thinking is, if it's about 1 foot towards A you can move your seat back a little farther.

[Z3_GoCar]

Slightly off the thread. In a left hand drive car (are there any right hand drive IT cars?) B-C makes sense, the question I have is: How close does B have to be to the corner of the cage? What I'm thinking is, if it's about 1 foot towards A you can move your seat back a little farther.
[/b]

Actually, no there are not any right hand drive cars in IT. There are in Production thought and maybe in Prepared if the JDM Silvias and other rhd cars come in from World Challenge/Grand Am. If David's conjecture is correct we may be seeing the start of a collapsed roll cage specification in that there'll no longer be a prod-cage or an SS/IT cage, it'll all be the same.

David, I agree the wrong place for a driver to sit is directly under the cage element, why aren't those cages declared unsafe and illegal by the Tech Stewards??

John, you should have a good look at my cage. MacMahn put a couple of little bends in the cross bar, then the diagonal is maybe 6"-8" from the end of the bend of the main hoop. This allows my seat maximum set-back room while not going underneath the main hoop.

James

[ddewhurst]

***How close does B have to be to the corner of the cage?***

John, without an engineering study there is no respectful/real safety response to answer your question. Safety responses/answers should not be made by someone with minimal or no engineering education. ;)

***What I'm thinking is, if it's about 1 foot towards A you can move your seat back a little farther.***

John, IMHJ when we start moving the main hoop diagonal from the left to the right we are starting to slide down the slippery slope that got us into this thread. As we move the diagonal towards the right so we have more room to move the seat back (exactly what the Production car owners did), next we also start bending the required main hoop horizontal rearwards (eliminating the main hoop horizontal as the Production car owners did) & next we are starting to move the seat backwards (exactly what the Production car ownwers did) & before ya know it we have the driver sitting under the main hoop which will not legally meet rule 18.1.2. (exactly what the Production car owners did) :) :) ;)

Have Fun ;)
David

ps: Before soemone runs to the Production car site with my responses within this thread my comments I beleive are spot on with how Production car roll cage items slipped down the slippery slope. I have attempted to engage the Production car site folks with some similar roll cage issues but people read & don't bite for fear of upsetting one from within their community.


***David, I agree the wrong place for a driver to sit is directly under the cage element, why aren't those cages declared unsafe and illegal by the Tech Stewards??***

James, I have a post within a roll cage thread on the Production car site at this time in which I ask questions about Production car drivers sitting under the main hoop with reference to the GCR roll cage rule 18.1.2. & the thread is falling fast to the second page.

Have Fun ;)
David

[JoshS]

Slightly off the thread. In a left hand drive car (are there any right hand drive IT cars?) B-C makes sense, the question I have is: How close does B have to be to the corner of the cage? What I'm thinking is, if it's about 1 foot towards A you can move your seat back a little farther.
[/b]

FWIW (not much in SCCA), the BMWCCA/NASA rules do specify the location of this diagonal:

"At least one (1) diagonal brace shall be used in the same plane as the main
hoop. One end of the diagonal brace shall attach to the corner, or horizontal
part, of the main hoop above the driver’s head, within twelve (12) inches of
the driver’s-side corner. The other end of the diagonal brace shall attach to
the mounting plate (or to the main hoop as close to the mounting plate as
practically possible) diagonally opposed to the driver’s head (passenger
floor)."

The SCCA rules don't appear to specify it.

[Greg Amy]

Do either of you two Greg's beleive that your personal safety is at it's best with the main hoop diagonal being attached any place other than at point B & point C with your left hand drive cars ?[/b]

I've actually been thinking about this since yesterday. Personally, I'm more comfortable with the diagonal in the main hoop plane, but that's because, well, I'm comfortable with it.

But consider that the purpose of the main hoop is to keep the roof from coming down on the driver's head; if you removed all rollcage elements except B-D, B-F, and B-E you'd still have a tripod there. Is that any better or worse than a B-D, B-F, B-C tripod? Dunno, not really sure if there's a functional difference in terms of "the tripod."

However, where I do see it making a difference is maintaining the integrity of the main hoop. The B-C element assists to maintain the C-A-B-D hoop. With only B-D, B-F, and B-E you run a higher risk of a B-A-C hoop failure upon a hard hit there, and then the entire hoop can collapse forward and to the right.

Personally I wouldn't build a cage without B-C. Optionally, I'd like to add B-E.

Side note: another thing I never noticed before: the front leg pads are listed as "bolt in pad". Odd. I predict that given all of us are going to be poring through the rules again we're going to find some very strange things that have been there for a long time. SCCA has opened a Pandora's box...

[Knestis]

... Personally I wouldn't build a cage without B-C. Optionally, I'd like to add B-E.[/b]

http://it2.evaluand.com/gti/images/mk3.2/cage09.jpg

Yup.

It's long been practice in FIA designs to do a B-E bar but no B-C bar (speaking generally, without reference to RHD vs. LHD issues). In a rally car, it's actually nice (spent some time in one with that design) because you have access to the rear seat space for helmet boxes, jackets, etc. but I tend to agree that I'd like to have a bar in as close to pure compression as possible, should large-magnitude acceleration vector ever be parallel to my backbone.

K

[ddewhurst]

If the rule writter & the rule approver had a clue they would not give the options that eliminated the need for a diagonal to be attached at both ends within the main hoop. Idealy attached at the upper left hand corner apex of the main hoop & idealy attached at the lowest end of the right hand upright of the main hoop. :) Keep in mind that the main hoop horizontal is REQUIRED.

Add any of the other optional main hoop diagonals you wish in conjuction with the previously stated main hoop diagonal because each of them will add to driver protection. ;)

Posted by Greg "the driver" A.

***Side note: another thing I never noticed before: the front leg pads are listed as "bolt in pad". Odd. I predict that given all of us are going to be poring through the rules again we're going to find some very strange things that have been there for a long time. SCCA has opened a Pandora's box...***

Presuming your making reference to the words within picture "Bolt in pad" It's only the lower right hand pad that requires to be bolted in. All other pads may be bolted or welded. :) :) ;) I beleive you prediction of opening Pandora's box is correct.

Have Fun ;)
David