Changes in the Door Bar Rules??

[Knestis]

I've heard rumors that there has been (or will be?) a change that requires "2 door bars" on both sides (again, ??) of IT cars. Or maybe new IT cars??

(That's a lot of question marks, huh?)

I don't remember seeing anything in recent FasTracks but my 'memberer is suspect recently - from old age and overwork, methinks. Anyway, has anyone seen anything like this, is it spillover from Spec Miata changes, or what?

The issue is that the triangulated structure we had in Pablo's doors...

http://it2.evaluand.com/gti/images/cage08.jpg

...might very fairly be considered to have a cross-sectional area of only one tube diameter, at the center of the main X. We're getting started on the new cage this weekend obviously don't want any surprises.

Have I just not been paying attention? :blink:

K

[Greg Amy]

Proposed, effective 2007. Require two side tubes both sides, allow NASCAR bars both sides including door gutting. See September 2005 Fastrack, page F-209. - GA

[Speed Raycer]

Kirk,

I've been wondering the same thing since most of the pass side bars I've done have been X's. Depending on the way its worded, X's could be "illegal" if it requires 2 bars from the main hoop to the front downbar.

Time for a clarification letter eh?

[Knestis]

Thanks, Greg. I don't know how I missed that. I swear that I looked! I don't think there's any need for "clarification" - it's clear that, if this is approved by the CRB, X door bars will be illegal.

K

[Bill Miller]

Originally posted by Knestis@Sep 21 2005, 11:24 PM
Thanks, Greg. I don't know how I missed that. I swear that I looked! I don't think there's any need for "clarification" - it's clear that, if this is approved by the CRB, X door bars will be illegal.

K

60875


Kirk,

I would agree that a traditional X bar, where you have one continuous bar, with 2 'cut' bars, would probably not meet the letter of the rule. However you could certainly make a 'siamesed' X, and use some of those neato gussets that Pablo has. Not sure what the difference in structural integrity would be.

As an alternative, you could run a traditional X, and put the second side tube down along the rocker

[joeg]

GUYS--MY next race is after October 1, 2005. Can I put my additional sidebars in now? (is the new rule officially adopted yet?); can I put the extra bar on one side now only (protruding into and gutting the door) and wait until the end of 2006 to do the other side?

They are not X-bars, so leave me out of that debate (which seems real silly as those X-bars are just fine.)

Regards.

[dickita15]

Originally posted by joeg@Sep 22 2005, 07:34 AM
GUYS--MY next race is after October 1, 2005. Can I put my additional sidebars in now? (is the new rule officially adopted yet?); can I put the extra bar on one side now only (protruding into and gutting the door) and wait until the end of 2006 to do the other side?

They are not X-bars, so leave me out of that debate (which seems real silly as those X-bars are just fine.)

Regards.

60891


You can certainly add extra bars now. you can not gut the right side door yet. the only two changes that are pending if I have it right are to require 2 bars (optional now), and allowing that gutting of the right door.

[dickita15]

Originally posted by Knestis@Sep 21 2005, 09:08 PM

...might very fairly be considered to have a cross-sectional area of only one tube diameter, at the center of the main X.

It would seem to me that the x would be legal. we have had no trouble with cage diagnals and horzontal bars intersecting in the same manner. I can however see how some ispector somewhere would make a different call.

It would seem as though the debate could be cleared up in the proposed gcr wording. was this a ITAC or RRB generated issue.

[Greg Amy]

Originally posted by Knestis@Sep 21 2005, 11:24 PM
...if this is approved by the CRB, X door bars will be illegal.

60875


I don't think so. The rule, paraphrased, is "...two sides tubes connecting the front and rear hoops across both doors is manadatory." There's nothing in there about requiring them to be horizontal (how would you enforce that anyway) nor anything describing that they cannot intersect (no specifics using the word "continuous" as in GCR 18.1.7.A. Further, any reputable mechanical engineer will attest that a properly welded parts are considered contiguous.

I think you're OK here with the welded X-bars. However, it never hurts to get a clarification. - GA

[Knestis]

This is going to confuse people - who assume that we will argue whatever suits our individual purposes, with whatever ammo we have available (see the 300ZX in ITS thread) - but I'm going to continue to argue that our triangulated X would be illegal if "two bars" are required. We would be wrong.

A cage builder on the East coast has made it common practice to leave the traditional parallel rear supports (from the main hoop) out of his designs, instead using ONLY an X. I've long argued that this approach does NOT meet either the letter or engineering aguments behind the requirement. Over some portion of that span downward to the rear end of the car, there is functionally only one tube there. The minimum cross-sectional area of the rear portion of the cage structure is just slightly over pi times one-half of the tubing diameter squared - or approximately "not very damned much."

To my mind, the same applies here.

Bill has actually hit upon exactly what we are going to do. :smilie_pokal: The new cage is going to rock.

K

[Bill Miller]

Originally posted by Knestis@Sep 22 2005, 12:13 PM
Bill has actually hit upon exactly what we are going to do. :smilie_pokal: The new cage is going to rock.

K

60941


So, which is it, siamese, or 2nd tube along the rocker?? Inquiring minds want to know!

It's all about thinking outside the box! :happy204:

[Knestis]

We're going to run one bar from the floor at the rear hoop, up to a center point in the door hole, then down to the forward upright. This one will have a twin running from shoulder height, down to the center of the door, then up to dash height in the front. They will meet at the apex of the X and be welded together along 3-4", then plated and gusseted.

The front downtube will be about 4" farther into the dash, which will allow our "WRC" diagonals to the top of the A-pillar to run straight and be farther from the driver's left hand. The main hoop will be about 3" farther back, to tie the structure together closer to where the rear beam bolts up, and we're going to be more assertive about the 100" plate rule, running two tubes from the front downtube to the firewall, right behind the strut turrets.

Finally, we're doing away with the fiddly little gussets, using full-diameter tube triangulation, a la typical touring/rally car current practice.

I still think that the crushable structure afforded by full doors is a valuable thing - moreso than NASCAR door bars.

K

[ddewhurst]

***- but I'm going to continue to argue that our triangulated X would be illegal if "two bars" are required.***

SURPRISE, we agree current "X". :023:

***We would be wrong.***

NAW...... ;)


Now just to add fule to the fire. Read the Production car rules & explain how they can fab a 3 tube door bar "X" with no horizontal & be legal.

Bill, I saw John's 2nd gen car parked at the Runoffs for sale with no price. Was he there ?

[Bill Miller]

David,

Yep, he was there. I believe he was crewing for one of the guys running a Porsche GT3 Cup car in GT2. That car is a steal, I think he's only aksing $6500 for it, and that's w/ a fresh motor and a MazdaComp trans (albeit missing 1st gear). Would need some race shocks, but other than that, it's a hell of a start to an EP car. Hell, the rolling chassis is worth what he's asking for everything.

[lateapex911]

Originally posted by Bill Miller@Sep 26 2005, 12:03 PM
David,

Yep, he was there. I believe he was crewing for one of the guys running a Porsche GT3 Cup car in GT2. That car is a steal, I think he's only aksing $6500 for it, and that's w/ a fresh motor and a MazdaComp trans (albeit missing 1st gear). Would need some race shocks, but other than that, it's a hell of a start to an EP car. Hell, the rolling chassis is worth what he's asking for everything.

61205



Further info, he is there crewing for Mike Piera, who is in a Porsche Cup car. (veeeeery cool car, BTW) ...from the inside it sounds so refined on the track! (My car sounds like a$$, LOL).

Mike is a guy who went to the Solo II Nationals for the first time, and WON in a '73 Porsche 911S Targa (!) when it was not the car to have. Smart and methodical, Mike has won his share, and then some, of races this year. We'll see how it shakes out when everybody bolts in their "A game" engines, but I pick him as a dark horse, and would not be at all surpised if he popped the champaigne.

Johns car needed a bit more than dampers. I'm not saying that the $ asked wasn't a fair price, but there is a HUGE shopping list and it's not cheap stuff. He has already parted out all the good stuff, and is just trying to wrap it up.

[Tyson]

whats the point of nascar bars on the passenger side for an IT car?

[lateapex911]

Originally posted by Tyson@Sep 26 2005, 07:12 PM
whats the point of nascar bars on the passenger side for an IT car?

61243


It's a guess, but I bet HQ wants more beef in the cars. A Touring driver was killed and the conclusion, from what i hear, was that better right side protection would have helped. It's great deal...as defined, NASCAR door bars are just about anything,,and you get to gut the door. I think it would be foolish not to take the offer.

It's a real cake and eat it too deal, YOU decide what the best door bar configuration is, as long as it meets the definition, and you get to take off a chunk of weight!

[Tyson]

yeah, im not talking the weight benefit. just why would the CRB allow this change since they have a history of only changing things on the basis of safety or factual error.


i suppose the only difference is that it changes the load path on a straight T bone more directly to the vertical bars (pushing instead of pulling the welds) but that doesnt mean anything to make a safer cage for the driver on the other side of the car. thats why im asking...

[Knestis]

It's off to get the cage installed by Competition Cages in Hillsborough, NC...

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

Look for our doorbar treatment to be a natural - and legal - extension of what we learned from the one in the pic above. That vertical element right next to the driver's left hand, by the way, resolved all of the load of our roll's impact above the A pillar strictly in compression.

There is NO evidence of deformation in the cage structure...

K

[Bill Miller]

Kirk,

I think I just came up w/ a name for the new car. Ugly Duckling!!!

[Catch22]

I would imagine that the intent of this rule is to get rid of the single bar side protection stuff. Like the old welded-in former autopower bolt-in cages.

Mine has a bar that runs along the rockers on both sides, and Xs on both sides (driver side protrudes into door, passenger side does not).
I would think this qualifies as 3 connections from the main hoop to the front.

Note the "I would think."

Scott, who has always, and still feels, that if I hit anything hard enough to seriously compromise the cage in my car I'm probably already screwed anyway.

[lateapex911]

Originally posted by Tyson@Sep 26 2005, 08:43 PM
yeah, im not talking the weight benefit. just why would the CRB allow this change since they have a history of only changing things on the basis of safety or factual error.
i suppose the only difference is that it changes the load path on a straight T bone more directly to the vertical bars (pushing instead of pulling the welds) but that doesnt mean anything to make a safer cage for the driver on the other side of the car. thats why im asking...

61248


Well a lot of cars have nothing on the pass side. Perhaps the CRb did it witha big picture in mind...it allows touring cars that have the door bars as required to migrate into IT, (if there is such a migration possible, perhaps it's paving the way for future moves),

and the weight break was seen as a "carrot" to get guys to put something...anything(?) in.

As it is, it is so open as to be very effective, IMHO.

[turboICE]

I would disagree that anything can be put in NASCAR style is defined and must intrude into the door cavity, not just any ole door bar is going to permit gutting.

[Bill Miller]

Yeah Ed, but there's no requirement on just how far or how much it must 'intrude'. So, if it intrudes by 0.1", you're allowed to gut the door.

[Knestis]

Originally posted by Bill Miller@Sep 27 2005, 02:20 AM
Kirk,

I think I just came up w/ a name for the new car. Ugly Duckling!!!

61263


That's your door, by the way, Bill. :D

[Bill Miller]

why do you think I felt the need to come up w/ a name???? :D

[Knestis]

Check out this shizznit, boyz...

http://www.desertrides.com/features/vehicles/gordonTT/images/DSC01922.jpg

From Robbie Gordon's trophy truck. More at...

http://www.desertrides.com/features/vehicles/gordonTT/

K

[Speed Raycer]

Originally posted by Knestis@Sep 29 2005, 06:27 PM
From Robbie Gordon's trophy truck. More at...

http://www.desertrides.com/features/vehicles/gordonTT/

K

61494


Anyone got a cigarrette??? I'm spent!!! :D

[itmanta]

That is some of the most retarded fabrication I have ever seen. What robot did the welds? That is just rediculous.

[lateapex911]

Spectacular...TIG, right?

Ever check out the welds on road and mountain bikes? Or even a Trac Rac? (the aluminum racks you mount on your pick up to carry lumber and ladders and such)

[Bill Miller]

Yeah Jake, that's TIG work. I actually have a friend that does work like that, the guy is just insane. I can't even imagine how many hours went into the fabrication of that car, it's mind boggling. Some very nice work, that's for sure!

[Geo]

I'm a little late to the party here, but I think Kirk needs to turn in his rules nerd badge. An "X" is comprised of two bars.

[Bill Miller]

Originally posted by Geo@Oct 5 2005, 10:08 PM
I'm a little late to the party here, but I think Kirk needs to turn in his rules nerd badge. An "X" is comprised of two bars.

61891


Actually George, it's comprised of 3 bars, 1 continuous one that runs from the main hoop to the front down tube, one that runs from the main hoop to the continuous bar, and one that runs from the front down tube to the continuous bar.

I personally think an X meets the spirit of the rules, but I can see where it could be argued that it does not meet the letter of the rules.

[Knestis]

I'm forced to try to be consistent, having argued for years that a car that has ONLY an X back from the main hoop to the strut tops (or wherever) doesn't have "2 bars" holding that hoop up. At one point in the structure, there is in fact only one tube of x-sectional area between the middle and the back end of the structure.

The same applies for door bars, to my thinking but we're dealing with that in the new design.

K

[dyoungre]

An 'X' in side view can be done with two bars - if the front and rear hoop are not in the same vertical plane - I've seen it done, where the two tubes are straight and crisscross without cutting; really depends on the shape of the roll hoops. It just needs one of the tubes to kick in at top or bottom (most likely bottom)

Question, though - are they still two tubes if the tubes are notched and welded, but not completely cut in two? Would such a design be inherently 'safer' than the 3 tubes Kurt described?

[jamsilvia]

Sorry, late to the thread.....


Originally posted by Knestis@Sep 22 2005, 11:13 AM
A cage builder on the East coast has made it common practice to leave the traditional parallel rear supports (from the main hoop) out of his designs, instead using ONLY an X. I've long argued that this approach does NOT meet either the letter or engineering aguments behind the requirement. Over some portion of that span downward to the rear end of the car, there is functionally only one tube there. The minimum cross-sectional area of the rear portion of the cage structure is just slightly over pi times one-half of the tubing diameter squared - or approximately "not very damned much."

To my mind, the same applies here.


I've wondered about this for a while too. I'm interested in thoughts about the rear X....

But I feel it's a bit different for the rearward X's vs the door X's. Why? Because the door X's possibly take a direct impact. Having only one door bar (or the equivalent cross section area) means that one bar of strength is taking the force of the impact.

For the rearward X, it keeps the main hoop standing and keeps the rear of the car mostly behind you in an impact.

In the case of the main hoop, any attempt for the main hoop to topple backwards puts compression loads through the bars of the X. Assumine the force is parallel to the bars, they should be plenty strong (and the triangles should be strong if the hoop trys to topple backward AND right/left).

In the case of rear impact, the forces are also compression loads through the X brace, just compressing towards the main hoop instead of away from it. Again, the rear X seems like it would be plenty strong in this sense too.

About the only issue I can see with the rear X is if a car jumps over your bumper and runs smack into the center of the X. It hits a weak point, and I'd guess that the thing is not very strong perpendicular to the X. I think it would buckle there. Especially considering how long those X's are for the rear (I have a cage built by the particular builder you speak of.)

And that impact seems like exactly what would happen in a side impact to the door X. The only thing keeping the X from collapsing with a perpendicular impact is the tension of the bars pulling at the main and front hoops. The weakest point in tension is the center of the X, which could pull apart from X to > < if the center shears. (I think true in a X-brace case too, including Pablo&#39;s one with the gussets - unless the top and bottom of the center X were also gusseted.) I think 2 complete side bars would double the amount of force required to shear, as well as spread the force over a larger area.

I guess this is off the topic of whether an X fits the rules or not, and more asking the question of what really is a good idea for side impact?

joe

[charrbq]

Two cents. I&#39;m not a welder, nor do I play one on TV, but I&#39;ve seen the need to use one in the past.

My guy tells me that it&#39;s much harder to make an "X" and gusset it properly than to weld two bars parallel to the front and main hoops. Plus, the bars are continuous, not cut and rewelded. As an aside, he offered to modify my cage in such a manor and add small bars between the main door bars to add support. His and my theory is that in a side impact event, with the "X" bar configuration, it would be a lot easier for the intrusion of cars and car parts into the cockpit than with the parallel bars.

I guess you could look at shark cages as an example. They put parallel bars in those to keep the bad things out.

[ddewhurst]

***An "X" is comprised of two bars.***

George, from my point of understanding the word TWO (& the rules) Kirk may keep his card.

Forgetting about the cute bend around/half cut bars that have been exposed within this thread to form the "X" side protection & "X" main hoop braces I understand the rules for both the side protection & the main hoop rear braces to say TWO tubes or two braces. Anyone who uses THREE seperate tubes/braces to fab the side protection or main hoop braces "X" is NOT legal to the written rule.

The next thing we&#39;ll have people fabing their main hoop out of several pieces of tube when the rule says one (1) continious length of tubing shall be used.

Opp&#39;s, how can I be so dumb. You folks are using new math & when the rule says TWO, the rule via new math really means THREE. :blink:

[RSTPerformance]

Originally posted by charrbq@Oct 6 2005, 11:43 AM
I guess you could look at shark cages as an example. They put parallel bars in those to keep the bad things out.

61944


I went into one of those shark cages this summer about 3 1/2 miles off the shores of Hawaii... Suprisingly I felt rather safe!!!

Ok so that has nothing to do with this, but whatever, it reminded me of our adventure...

Raymond "shark bite" Blethen

[Geo]

Originally posted by ddewhurst@Oct 6 2005, 05:15 PM
***An "X" is comprised of two bars.***

George, from my point of understanding the word TWO (& the rules) Kirk may keep his card.

Forgetting about the cute bend around/half cut bars that have been exposed within this thread to form the "X" side protection & "X" main hoop braces I understand the rules for both the side protection & the main hoop rear braces to say TWO tubes or two braces. Anyone who uses THREE seperate tubes/braces to fab the side protection or main hoop braces "X" is NOT legal to the written rule.

The next thing we&#39;ll have people fabing their main hoop out of several pieces of tube when the rule says one (1) continious length of tubing shall be used.

Opp&#39;s, how can I be so dumb. You folks are using new math & when the rule says TWO, the rule via new math really means THREE. :blink:

61957


God, this sort of stupid stuff is the resaon I&#39;ve not been around for a while. While I am not a tech inspector, I&#39;m confident they won&#39;t be so goofy about this. An X is two tubes.

There are many times I think this site does more harm than good.

[Geo]

Originally posted by charrbq@Oct 6 2005, 03:43 PM
Two cents. I&#39;m not a welder, nor do I play one on TV, but I&#39;ve seen the need to use one in the past.

My guy tells me that it&#39;s much harder to make an "X" and gusset it properly than to weld two bars parallel to the front and main hoops. Plus, the bars are continuous, not cut and rewelded. As an aside, he offered to modify my cage in such a manor and add small bars between the main door bars to add support. His and my theory is that in a side impact event, with the "X" bar configuration, it would be a lot easier for the intrusion of cars and car parts into the cockpit than with the parallel bars.

I guess you could look at shark cages as an example. They put parallel bars in those to keep the bad things out.

61944


They use parallel bars because the spacing between the bars must be small.

A properly designed and executed cage with an X will tie to the dash crossbar and main hoop horizontal crossbar. This will be significantly stronger than two parallel bars welded to verticle tubes without other support.

[Knestis]

FWIW, the first conversation about the X-only rear main hoop brace design - where the rules also call for "two bars" - was with an SCCA tech inspector, who I actually don&#39;t think of as outside of the mainstream.

I didn&#39;t say that it necessarily made simple sense, I just call &#39;em as a I see &#39;em. Sometimes I&#39;m way off base but regardless of what we think common sense might prevail, we&#39;re playing it safe.

It took a week or so for the 1.5x.065" DOM tube for our secondary cage elements to come in but Competition Cages will get to bendin&#39; this weekend.

K

[Bill Miller]

Originally posted by Geo@Oct 6 2005, 09:15 PM
God, this sort of stupid stuff is the resaon I&#39;ve not been around for a while. While I am not a tech inspector, I&#39;m confident they won&#39;t be so goofy about this. An X is two tubes.

There are many times I think this site does more harm than good.

61992


You can say it is all you want George, but that doesn&#39;t make it the case. And you know what happens when someone writes a protest? They go by what it says in the book, not what somebody feels (at least, that&#39;s the way it&#39;s supposed to work).

[JLawton]

The big question (for those of us that have door bars in an "X") is the X design legal (although one bar is cut and re-welded). Is my design going to be ok or am I going to have to put door bars into my budget for next year........

[ddewhurst]

***God, this sort of stupid stuff is the resaon I&#39;ve not been around for a while. While I am not a tech inspector, I&#39;m confident they won&#39;t be so goofy about this. An X is two tubes.***

As you said George, you are not a tech inspector. The rules don&#39;t say anything about the reader confidence factor & some tech inspectors will read the rule the same as some of us read the rule. Many of us who are being GOOFY understand the meaning of the words one, two & three.

[dickita15]

geo
I feel your pain. many of my IT friends get frustrated reading threads like this. I am a tech inspector and as I said ealier i would accept the x as two bars so anyone who want to tow up here I will issue a log book, but I can see some inspectors questioning this. Those type of decisions are what made me become a tech inspector. I find value in this type of thread as it helps me refine my argument and makes me more effective in defending truth justice and the american way. :D

besides we are still a lot less silly the the production board.

[Greg Amy]

Originally posted by dickita15@Oct 7 2005, 07:44 AM
Those type of decisions are what made me become a tech inspector.
62010


Ditto. I&#39;ll sign off a logbook that has this arrangement, and if you get protested/bumped by Tech for it, I&#39;ll help you write the appeal. - GA

[lateapex911]

WOW! How cool is that! Open, forthright, and loaded with moxie! Two tech inspectors with integrity.

The one or two question is interesting. If you were a tiny being that could pass through the molecules of steel, and you were in the main bar of the X, traveling from one end to the other, you would have an uninterupted trip, right? Nothing but steel molecules.
Now if you were in the interupted bar, along the outside edge, traveling along it&#39;s length, you would enjoy the same uninterupted trip, right?

but if you were traveling along the top or the bottom, again, in the metal, you would be greeted with an air space at the junction, correct?

So, my answer is that they are actually 1.5 (or so bars), as the second bar isn&#39;t truly continuous.

But does it really matter?

[dickita15]

Originally posted by lateapex911@Oct 7 2005, 05:05 PM
So, my answer is that they are actually 1.5 (or so bars), as the second bar isn&#39;t truly continuous.

62063


i may be mistaken jake but i do not remember anything in the new rules about the two tubes being continuous

see geo what we have to put up with :lol:

[ddewhurst]

"Item 5. Effective 1/1/07 and permissible 10/1/06: Allow NASCAR-Style side bars on the passenger side of Showroom Stock, Spec Miata, and Improved Touring competition cars. Change section 18.2.7 to read as follows:

7. Side Protection
Effective 1/1/07 and permissible 10/1/05 >>>>TWO (2) side tubes<<< connecting the front and rear hoops across both door openings are mandatory. Door side tubes may extend into the door... etc. etc..."

TWO side tubes:

One (1) side tube = l

TWO (2) side tubes = l l

Three (3) side tubes = l l l

In common sense understanding of a non strained & or non tortured interperation (rule 1.2.4.) of the rule TWO (2 = l l) is very straight forward & simple to understand.

Will anyone who defines TWO (2 = l l) as being THREE (3 = l l l ) please provide their definition.

Maybe the fact that Production rules have been so far out of control for many years is because some tech inspectors have also been out of control. Did any of you tech inspectors from the North East (or any other Division) inspect Harold&#39;s F Production side hoops that DO NOT follow the front pillars, that travel through slots in the hood & terminate at the front spring towers ? That friends is how the Production rules have been CREEPED for many years & now we have some on this site within this thread that are IMHJ willing to creep the Improved Touring RULES. Another Production car from the North East has the main hoop traveling over the drivers head with no main hoop diagonal & the head restraint is 6 inches behind the trailing edge of the main hoop. Yup, it ain&#39;t hard to figure out how rules CREEP occures. But then with the new math & all three equals TWO. ;)

Golly, because the rule don&#39;t say continious lets make our side hoops, halos & main hoop diagonal out several pieces of tube. :bash_1_:

[turboICE]

Originally posted by ddewhurst@Oct 8 2005, 11:01 AM
TWO (2) side tubes connecting the front and rear hoops
62097

I don&#39;t know but it is pretty clear to me. Each of the two tubes need to connect one end to the front hoop and the other to the rear hoop. No where in there does it say connect one tube to the front and rear hoop and another tube from the rear hoop to the first door tube and another tube from the front hoop to the first tube.

The second "tube" is no longer one tube, over an inch of it is missing if you were to draw a line from where it meets each hoop. And neither of the two pieces of that tube connect the front hoop to the rear hoop.

I see no reasonable way without an overly burdened interpretation of the rules to conclude a typical X bar alone meets the requirement. IMO to conclude the tubes that intersect the actual complete tube connect the front to the rear is a real stretch and NOT in the spirit of the rule at all.

[Greg Amy]

Originally posted by ddewhurst@Oct 8 2005, 11:01 AM
Will anyone who defines TWO (2 = l l) as being THREE (3 = l l l ) please provide their definition.
62097


Any first-semester welding school student can tell you that any two pieces properly welded together will be considered contiguous and as strong as the original pieces (and, in most cases, stronger). Therefore, any two (or more) tubes welded together can be considered contiguous (unless SCCA has a specific definition otherwise that I&#39;m unaware of. Is there?)

In fact, even though in many cases SCCA *specifically* calls out a continuous tube (such as the main hoop) they tacitly recognize that multiple tubes can be made so by the use of internal tubing and rosette welding.

If you want a definition, dig out the ASTM specs.


The second "tube" is no longer one tube, over an inch of it is missing if you were to draw a line from where it meets each hoop.

Not true. At worst, taking your logic to the extreme, these tubes will have two small holes in the side. Imagine creating an "X" by bisecting one and welding to a contiguous tube. Then, cut away the originally-contiguous tube. You&#39;re left with one tube with two holes. However, you&#39;re thinking that the bisected tube is now less strong since it&#39;s got "holes". Not true. In a properly-built X bar, all tension and compression forces on the bisected tube are transferred through the "arch" in the the contiguous tube, then back to the other bar, and that arch is supported by the existing tube in the other plane. It&#39;s just as strong as a contiguous tube.

Bottom line: "two" tubes welded in an X, with one contiguous and the other bisected and welded to the first, is as strong - I would argue stronger - as two bars welded parallel and/or horizontal between the front and rear. It&#39;s certainly better than two bars laid in a different plane and welded in the middle as a psuedo-"X". You may disagree, but I personally have no plans to modify my existing "X" on the passenger and driver&#39;s side, except to as an excuse to remove passenger-side glass and mechanisms... - Greg

[chuck baader]

One other thing to consider...straight tubes carry loads, bent tubes are springs: Therefore, the "X" on the passenger side is ultimately stiffer than the NASCAR door bars on the driver&#39;s side. The crush space, however is worth it to me. Chuck

[Bill Miller]

Therefore, any two (or more) tubes welded together can be considered contiguous (unless SCCA has a specific definition otherwise that I&#39;m unaware of. Is there?)




[devil&#39;s advocate]Well Greg, what you&#39;ve just argued, is that an X configuration is in fact one tube. B) ;) :023: :happy204: :D [/devil&#39;s advocate]

[Greg Amy]

(Argh, I&#39;m gonna slap you nex time I see you...) Taking it to the Miller extreme, the entire rollcage is thus one single bar... (your move... :) )

[Bill Miller]

Originally posted by GregAmy@Oct 8 2005, 05:31 PM
(Argh, I&#39;m gonna slap you nex time I see you...) Taking it to the Miller extreme, the entire rollcage is thus one single bar... (your move... :) )

62111


Agreed Greg, that&#39;s why I think your original logic is flawed.

Here&#39;s another way to look at it. How many tubes are attached to the continuous tube that is between the main hoop and the front hoop/downtube, not including the main hoop and the front hoop/downtube?

As I said, I think it meets the spirit of the rules, but unless a clarification is made to allow it, it&#39;s just too easy to argue that there are not two tubes connecting the main hoop to the front hoop/downtube. And the two tubes that make up the non-continuous leg of the X, aren&#39;t welded together, they are welded to the continuous tube. So, per Greg&#39;s comment, they are not two tubes welded together (and thus not contiguous).

[Speed Raycer]

Ok... lets play "How many tubes are there?" No fair picking through the build-up pics.

http://www.izzyscustomcages.com/images/Cag...gePainted05.jpg (http://www.izzyscustomcages.com/images/Cages/NewRXCage/CagePainted05.jpg)
{edited to speed the page load up}

[ddewhurst]

Greg, if two pieces welded together is stronger than one piece why SHALL the main hoop be one continious tube ? By your logic we would all have STRONGER/SAFER main hoops if several pieces were welded together to fab our main hoop.

No comment from either of the North East tech inspectors about the two previously mentioned ILLEGAL North East roll cages.

Now for a bit of humor. Greg, how long is a piece of string ?

[Greg Amy]

Originally posted by ddewhurst@Oct 9 2005, 07:47 AM
...if two pieces welded together is stronger than one piece...I really have no desire to get into a dewhurst BB pissing match, but I do believe I wrote "...as strong as...", not "stronger than". If I wrote otherwise then you can consider this a correction to that effect.

BTW, if you read GCR 18 carefully, there are instances where even the continuous bars need not be so if properly done (support tubing, rossette welds).


Now for a bit of humor. Greg, how long is a piece of string ?Depends on how far apart your jackstands are...


To all: As I said, I will sign off a logbook with a properly-done X-bar, but I accept the possibility that SCCA Topeka may disagree. If that happens, a clarification will be issued. However, this is quickly turning into an "angels on the head of a pin" argument, so to completely avoid this argument it&#39;s a simple matter of welding a horizontal tube across the bottom of the door to supplement the X. Further, it&#39;s going to be very diificult to make effective &#39;into the door&#39; bars without using multiple tubes (you can see, in fact, that&#39;s exactly what we did: http://www.kakashiracing.com/images/rollcage/DCP_4707.JPG) (http://www.kakashiracing.com/images/rollcage/DCP_4707.JPG). - GA


(On edit: Dewhurst, I see my original reference to "stronger". In context, I mean that, for example, when two plates or tubes are welded together, the actual weld itself is stronger than any particular area of the contiguous plate or tube. I do not mean to imply that the resulting structure is stronger than a contiguous plate because, obviously, it cannot be: any structure is only as strong as its weakest point.)

[Bill Miller]

Greg,

That link doesn&#39;t work, 404 error

[Eric Parham]

The link worked fine for me just now. I like Greg&#39;s door bars. :023:


Originally posted by Bill Miller@Oct 9 2005, 01:16 PM
Greg,

That link doesn&#39;t work, 404 error

62137

[Bill Miller]

Yep, seems to be fixed now. And yes, that&#39;s a nice setup

[dickita15]

David.
harold has lived in florida for a number of years and though he keeps his region of record up here he only tows up for a couple of races in mid season. His annuals are done in the south east. I have not given his setup much thought but if it is illegal I am suprissed no one has made a deal of it at the runoffs. knowing harold I doubt it because he is under the radar.

As to the second car I have no idea what car you are referring to but IF it is as you say it does not sound right.

I certainly understand your argument against the X but like greg I belive differently. And like greg I will accept a higher authority telling me I am wrong. what I do not understand is why you are so disrespectful to those that disagree with you on such a point.

[ddewhurst]

****In context, I mean that, for example, when two plates or tubes are welded together, the actual weld itself is stronger than any particular area of the contiguous plate or tube. I do not mean to imply that the resulting structure is stronger than a contiguous plate because, obviously, it cannot be: any structure is only as strong as its weakest point.***

Greg, I agree & I didn&#39;t have a desire to start stating facts out of books. I do have a question for you about the cage picture you posted. When I look at the drivers side B pillar vertical tube with a bend that looks to be directed to the left, the main hoop diagonal looks like it passes behind this B pillar tube. Using the words of Dick I&#39;m not being disrespectful to your project I&#39;m only asking a question of what you have & what my eyes see. ;)

***what I do not understand is why you are so disrespectful to those that disagree with you on such a point.***

Dick, my intent is not to be disrespectful to anyone. We all have different presentation skills. IIRC Harold&#39;s car has been the same since I first viewed the car at the 1997 Runoffs & it was bitched about & or protested IIRC at the 2004 Runoffs. The second car I mentioned is the H car of Ron Bartell. I do not bring these cars up to be disrespectful to the drivers. Sometimes when it comes to rules it appears to be stature of drivers that answers the legality of rules. I bring the cars up to attempt to make a point of how the Production rules have CREEPED & if WE in the Improved Touring community start doing the same type of things by twisting the rules with our roll cages, side protection, & other items WE will be in the same boat.

A thought I have had about the new IT side protection rule as I understand the rule is that maybe the CRB is trying to align the IT side protection rule with the Production side protection rule. The "X" for side protection will not meet the Production side protection rule unless there is a horizontal tube from the main hoop to the front /side hoop above the "X".

The one item WE all should remember is that the main purpose/intent of the roll cage is to protect the driver. In my humble belief N_ _ _ _R has driver horizontal side tube protection for a very good reason.

[Greg Amy]

Originally posted by ddewhurst@Oct 10 2005, 09:15 AM
...a question for you about the cage picture you posted.
62191


From the other side. We did it this way for a few reasons:

- Allows the main hoop to be placed as far back as possible for driver clearance
- Allows the door bars to protrude farther into the door cavity (with the main hoop so far back the door bars would either have to be bent - making them less strong - or nearly flat instead of protruding)
- Creates more roll structure over the driver for crush protection

http://www.kakashiracing.com/images/rollcage/DCP_4711.JPG
http://www.kakashiracing.com/images/rollcage/DCP_4697.JPG
http://www.kakashiracing.com/images/rollcage/DCP_4724.JPG
http://www.kakashiracing.com/images/rollcage/DCP_4721.JPG

[dickita15]

Originally posted by ddewhurst@Oct 10 2005, 09:15 AM
A thought I have had about the new IT side protection rule as I understand the rule is that maybe the CRB is trying to align the IT side protection rule with the Production side protection rule. The "X" for side protection will not meet the Production side protection rule unless there is a horizontal tube from the main hoop to the front /side hoop above the "X".

62191


David that is an excellent point, logical progression and lack of conflict between the different catagories has been a stated goal of the CRB. maybe the CRB should just adopt the prod side protection wording, the would only have to add the door gutting wording.

by the way while reviewing the prod cage wording I found this 18.6.b.2 open top automobles without a windshield and with a high front hoop design....since the windshield frame is to be removed there is no requirement to follow the line of the A- pillar. Not expressing an opinion, just happened upon this.

[ddewhurst]

Greg, I presumed something slightly different was being fabed. Thanks for the pictures.

[ddewhurst]

Dick, when we look at the GCR/PCS with respect to roll cages we will find there are some considerable re-writes since the 2004 GCR/2004 Runoffs. You will also note that ALL cars must have the correct shaped main hoop by 1/1/207. The CRB is & has been in full swing for a couple years trying to get roll cages brought to some common sameness instead of the free for all that has been going on for a bunch of years. When I read the 2004 PCS or the 2005 GCR (the Production roll cage rules have been rolled into the GCR for 2005) for Production roll cage side hoops the wording is considerable for 2005. BUT, when I read rule GCR 18.6.b.2.a. the side hoops are to be identical for open tops with windshields & for open tops without windshields except for GCR 18.6.b.2.a.1. & 2. meaning the side hoops front down tube will terminate within the cockpit. & in Production the TWO required side protection tubes SHALL be connected to the front & rear hoops across both the door openings. Harold&#39;s side protection tubes DO NOT connect to the front hoop/side hoop. His side protection tubes connect to a secondary support brace that connects to the side hoop up high & traveles to the floor down low.

With tongue in cheek ;) I say that according to some peoples thoughts that diagonal brace is the side hoop.

[Speed Raycer]

I realize that this wont mean much during a protest, but here&#39;s a little clarification I received from Topeka (and the email I sent for ya&#39;ll to rip through my leading wording ;) :

-----Original Message-----
From: Izzy&#39;s Custom Cages {edit}
Sent: Saturday, October 08, 2005 12:46 PM
To: Jeremy Thoennes
Subject: New SS, SM, IT door bar rule

Jeremy,

I&#39;m seeking a clarification of the new IT, SM, SS doorbar rules.


"Item 5. Effective 1/1/07 and permissible 10/1/06: Allow NASCAR-Style
side
bars on the passenger side of Showroom Stock, Spec Miata, and Improved
Touring competition cars. Change section 18.2.7 to read as follows:

7. Side Protection
Effective 1/1/07 and permissible 10/1/05 >>>>TWO (2) side tubes<<<
connecting the front and rear hoops across both door openings are
mandatory.

Does this new rule make an X bar illegal if using one continuous bar and
two shorter bars?

Thanks for any clarification you can provide.
----------------
Subject: RE: New SS, SM, IT door bar rule View Full Header
View Printable Version
From: "Jeremy Thoennes" <edit for spammers>
Date: Mon, October 10, 2005 3:44 pm
To: "Izzy&#39;s Custom Cages" <edit>
Priority: Normal



No, x braces would still be allowed.

-Jeremy
------------------

[ddewhurst]

With no disrespect to Jeremy I beleive his response makes no sense with respect to the written IT side protection ruel for 1/1/07. I have written Jeremy explaining to him my understanding of the new 1/1/07 IT side protection rule suggesting that the "X" is not TWO tubes with each connecting the front hoop to the rear hoop. I suggested to him that the "X" is in fact THREE tubes of which one tube is connected to the front hoop & the rear hoop & that each of the other two tubes has one end connected to one hoop & the other end of the same tube is connected to the single tube that is connected to the front hoop & the rear hoop. I suggested that there is a contradiction between the "X" (three tube) & the new rule (two tube) asking for an explanation before we in IT have a farce like the Production main hoops which are required changed by 1/1/07.

IMHJ this whole IT side protection rule is a very large joke. The GT cars & the Production cars have the exact same rule & the "X" is not legal UNLESS there is a horizontal tube above the "X". If the CRB thinks the "X" alone dose not provide enough driver safety for the GT & Production drivers then why do some IT people think the "X" provides proper safety for IT drivers. Are the IT cars play toys compared to the GT & Production cars or are they somewhat equal. IMHJ the IT cars should have the same side protection rule. But no the CRB can&#39;t admit that the IT red headed stepchild cars are real race cars & require the same side protection rule/driver safety as the GT & Production cars.

Next letter is to the CRB.................. Requesting that the IT side protection rule be written with the same words as the GT & Production side protection is.

Please take your best shots. I&#39;ll appreciate your thoughts to either strengthen my presentation letter to the CRB or decide that a letter is not required.

[Geo]

This is silly. What makes you presume the Production and GT cage rules are better? I don&#39;t think they are. In fact, I think they are rather poorly conceived and written are probably the results of minor dinking with the wording over the years resulting in silliness.

IMHO (what does IMHJ mean?) Production and GT cage rules should be more similar to IT cage rules (including the X being legal).

[lateapex911]

In MY Humble Judgement

[dickita15]

Originally posted by ddewhurst@Oct 10 2005, 09:55 PM
With no disrespect to Jeremy I beleive his response makes no sense with respect to the written IT side protection ruel for 1/1/07. I have written Jeremy explaining to him my understanding of the new 1/1/07 IT side protection rule suggesting that the "X" is not TWO tubes with each connecting the front hoop to the rear hoop. I suggested to him that the "X" is in fact THREE tubes of which one tube is connected to the front hoop & the rear hoop & that each of the other two tubes has one end connected to one hoop & the other end of the same tube is connected to the single tube that is connected to the front hoop & the rear hoop. I suggested that there is a contradiction between the "X" (three tube) & the new rule (two tube) asking for an explanation before we in IT have a farce like the Production main hoops which are required changed by 1/1/07.


62252


excelent david. we have an opinion. you are articulating the other side of the argument. I am willing to comply with what ever his responce is.

the cage rules for all the catagories need to be brought more in line, The rrb has said they want better progression between catagories. Touring, Improved Touring, Grand Touring. pick a car and keep pouring in money, :)

[ddewhurst]

***What makes you presume the Production and GT cage rules are better?***

George, I didn&#39;t say the Production and GT "cage " rules are better. I said :) that IMHJ the side protection rule in IT should be the same as the side protection rule in Production & GT.


***In fact, I think they (Production & GT cage rules) are rather poorly conceived and written are probably the results of minor dinking with the wording over the years resulting in silliness.***

George, I agree with you. ;)

IMHJ the new IT side protection rule is poorly conceived & writen which will allow silly personal random fabricating of side protection.

[Geo]

David, my point was why should IT conform to Prod and GT? I think the whole group of cage rules should be rewritten. If that happens, then something more along the lines of the rules for IT would make more sense. From a liability standpoint I think the club should not get too specific about some things because people can disagree about what is safer. My my hide I&#39;m going with an X. I believe it to be safer than NASCAR bars, especially as loosely defined in the GCR.

[Bill Miller]

George,

An X is fine, and if you feel that&#39;s the safer route, go that way. Just add an additional tube, above or below the X. As it stands now, an X does not meet the letter of the new rule. I&#39;m sorry if you don&#39;t like that, but that&#39;s the way it is.

I appreciate the comments from the tech folks (Greg and Dick, et al)about allowing the X. I would caution you, that since an X does not meet the letter of the new rule, allowance of a non-compliant configuration opens you up to some liability. God forbid that something happens, and someone gets hurt/killed, and it&#39;s found that they have a non-compliant cage. They&#39;re going to go to the car&#39;s logbook, and see who approved the non-compliant structure. I won&#39;t even go into re-writing the rules in the tech shed.

This issue needs input from a higher authority (CRB or BoD), w/ a definative position on the compliance (or lack thereof) of an X configuration, in an IT car.

[Greg Amy]

Bill, express approval of the Club Racing Technical Manager isn&#39;t enough for you? What do you want, a letter from the CRB? If so, what did your letter/email to them say when you sent it this week requesting such?

And the veiled "threat" of liability is not only silly, it&#39;s insulting. If I lived my life worrying about what a lawyer and his client might do, I&#39;d never leave the covers in the morning (in fact, I&#39;d probably worry about cancer from the detergent or something). Comments/threats such as that are just so stupid on so many levels it just makes me ill.

Bill and David, just let it go. Personally, your opinion on this matter is irrelevant; the rest of us are going to follow what we believe is right, not how many angels there are on that there pinhead. It&#39;s just so silly (at the very least) to sit there and argue that you approve what I may be doing as the spirit of the rules but believe that it&#39;s against the letter of the rules and I shouldn&#39;t be doing it. Fine, I invite your protest.

If you believe the X design is not as strong as two parallel bars, then I can accept you&#39;re wrong and we can agree to disagree. If you believe that the X is fine from a strength perspective but it bothers you that this may be technically against the letter of the rules then get the rule changed to something you do like. In either event, as far as I&#39;m concerned, this discussion is done. - GA

[ddewhurst]

Hey guys, check out my main hoop. Ol Gomer at the feed mill thought I should copy the main hoop on his lawn tractor. Pretty neat eh........

http://seeitornot.faketrix.com/crashing-photos-60.htm

[Bill Miller]

Greg,

I&#39;m sorry you took my comments as a veiled threat, because they were certainly not meant to be anything of the sort. I was simply pointing out what I thought was a potential issue.

And no direspect to Jeremy, but his opinion, is just that, his opinion. It, along w/ $1.50, will get you a cup of coffee at the protest hearing. It&#39;s what&#39;s written in the rule book that matters. Or, that notwithstanding, what the CoA rules on.

And it really has nothing to do with my opinion on which is the better design (from a structural or safety point of view). As I&#39;ve stated several times, I think that an X meets the spirit of the rules. But, until it explicitly states that, the new rule, that is required 1/1/07, does not allow it. I&#39;m sorry if you think I&#39;m just being silly, but you get used to that, being a rules nerd and all. As I said, how many tubes are attached to the continuous tube that connects the main hoop to the front hoop? You can&#39;t say the non-continuous tubes are welded together, to form a continuous tube, because they&#39;re not, they&#39;re welded to the continuous tube. So they only way the non-continuous tubes connect, and join the main hoop to the front hoop, is by being welded to the continuous tube. No matter how you slice it, that is not two tubes, that connect the two hoops.

[Drew Aldred]

Originally posted by ddewhurst@Oct 10 2005, 12:37 PM
You will also note that ALL cars must have the correct shaped main hoop by 1/1/207.


Well KINDA anyway. My understanding is that this applies to any NEW production cage builds. There is still going to be some gray area for those cages already built, assuming the owner can show how safe the design is for his car.

I&#39;ll admit to not going to the Prod tent meeting this year, I&#39;d seen that show before. So if there was any new info there, I didn&#39;t hear it.

Carry on with this good discussion, I&#39;ll go back to lurking.

[ddewhurst]

Drew, go read the Production main hoop rule for 1/1/07 & forget the Production gossip. ;)

Now back to the regularly scheduled pi$$ing contest about the new IT side protection rule for 1/1/07. With no disrespect or respect to anyone here are some facts that kind of agree with what Bill Miller stated.

What Jeremy says is about rules is OPINION just like what WE say about rules.

Rule 13.9 for $250.00 is just another OPINION.

Nothing means nothing about a rule untill something is protested & a decision is complete then the OPINION is gone. It&#39;s fact..............

When Jeremy & I finished our e-mails back & forth I presume Jeremy had a sizeable question that I planted in his mind based on the following question I asked him which he will forward to the CRB as a rule request.

"If the CRB is going to specify a new side protection rule for IT why didn&#39;t they use the same rule that the GT & Production classes have ?"

I will accecpt that the current GT & Production side protection rule provides adequate side protection beyond the proposed new IT side protection rule where every Tom, dick & Harry can fab side protection to their own ability. No disrespec to anyone. :rolleyes:

I understand that Topeka has no desire to take liability & I also understand Topeka has no desire to restrict peoples choice of freedom in design. BUT, many of us DO NOT HAVE THE ABILITY to design & or fab roll cages or side protection.

[seckerich]

I ran this up the pole a few times in the past and was told the word "continuous" makes the difference. The rules state we must have a bar at shoulder height connecting the main hoop behind the driver--but most go through the diagonal as two pieces? Never says it must be continuous, just there. Same goes for the x bars. Only thing that makes x illegal in production is the statement about horizontal. Sometimes you must read what is left out as well as what is written.
Steve Eckerich

[Geo]

Originally posted by Bill Miller@Oct 12 2005, 10:58 AM
George,

An X is fine, and if you feel that&#39;s the safer route, go that way. Just add an additional tube, above or below the X. As it stands now, an X does not meet the letter of the new rule. I&#39;m sorry if you don&#39;t like that, but that&#39;s the way it is.


I appreciate the advice Bill. I already have a tube from the base of the main hoop to the base of the front supports. That said, I wouldn&#39;t have worried anyway.

[Drew Aldred]

Originally posted by ddewhurst+Oct 12 2005, 05:46 PM-->
What Jeremy says is about rules is OPINION just like what WE say about rules. [/b]
I&#39;d tend to give Jeremy&#39;s opinion a little more weight than what is bantered about on a discussion board.

Originally posted by ddewhurst@Oct 12 2005, 05:46 PM
Rule 13.9 for $250.00 is just another OPINION.
And a rule that I believe has only been used twice since it was put on the books. Even if something gets protested and a ruling made, you can still appeal it or try to get the rule modified. No real permanant facts forever, much like the legal system.

<!--QuoteBegin-ddewhurst@Oct 12 2005, 05:46 PM
I understand that Topeka has no desire to take liability & I also understand Topeka has no desire to restrict peoples choice of freedom in design.

OK, NOW we are getting somewhere. This is a real truth and a reason why I&#39;d caution anyone on tearing out their cage to meet the rules for 2007. SCCA doesn&#39;t want to get into telling you how to design a cage and then be on the hook if it fails. The liability is too great, this is why there will be some grey area to this roll cage rule. Call it gossip all you want David, but SCCA isn&#39;t going to pay out a huge sum to cover a failure of their "mandated roll cage".

Back on topic, change to wording to duplicate the prod side door rules. Makes it easier to go from Prod to IT. I&#39;m sure it was just an oversight, not trying to make anyone&#39;s life harder or to make drivers jump hoops to be compliant.

[Bill Miller]

Drew,

The SCCA already mandates our cage design, just look at the GCR.

[ddewhurst]

I understand hat IF is the biggest little word in a dictionary. But IF the IT rule was changed to the exact same rule as the GT/Production side protection rule an "X" with a horizontal tube below the "X" would not meet the rule.

***I appreciate the advice Bill. I already have a tube from the base of the main hoop to the base of the front supports. That said, I wouldn&#39;t have worried anyway.***

I am either building or buying a different car & I really could care less what the side protection rule is for IT other than consistency between OEM type race cars would make common sense. I will have side protection that will allow me to transfer to race in Production with the same car. Notice I didn&#39;t say win in Production, I said race. ;)

Drew, I don&#39;t race the protest/appeal circuit. The only time I came close to a protest towards someone was during my first year with the Spec-7 I mentioned to two racers that if they had the same illegal exhaust (they both knew they were illegal) the following year I would protest them. Never happened because they both went to different classes. :023:

[Drew Aldred]

Originally posted by Bill Miller@Oct 13 2005, 06:06 AM
Drew,

The SCCA already mandates our cage design, just look at the GCR.

62511




:lol: Bill, good one. As you know every cage design matches the drawings in the GCR. B) Too many different cars to have a spec cage design.

[Geo]

Originally posted by ddewhurst@Oct 13 2005, 01:03 PM
I understand hat IF is the biggest little word in a dictionary. But IF the IT rule was changed to the exact same rule as the GT/Production side protection rule an "X" with a horizontal tube below the "X" would not meet the rule.


1) I couldn&#39;t care less. You are the only person who seems to have an agenda to make the IT cage rules the same as the Production cage rules.

2) I was simply responding to Bill&#39;s suggestion.

[Knestis]

http://it2.evaluand.com/gti/images/mk3.2/doorbars1.jpg

It&#39;s a little sharper in real life but here&#39;s the new door structure, before the taco gussets and/or plating go on. They are pyramidic, poking outward about 5" into the door panel but not penetrating the sheetmetal structure. With the smaller diameter tubing, it really seems roomy in there now.

http://it2.evaluand.com/gti/images/mk3.2/cage01.jpg

The rear of the cage is essentially like the last one, with the additional diagonal down from the struts to the bottom of the main hoop.

K

[lateapex911]

Originally posted by Knestis@Oct 22 2005, 07:05 PM
http://it2.evaluand.com/gti/images/mk3.2/doorbars1.jpg

It&#39;s a little sharper in real life but here&#39;s the new door structure, before the taco gussets and/or plating go on. They are pyramidic, poking outward about 5" into the door panel but not penetrating the sheetmetal structure. With the smaller diameter tubing, it really seems roomy in there now.

http://it2.evaluand.com/gti/images/mk3.2/cage01.jpg

The rear of the cage is essentially like the last one, with the additional diagonal down from the struts to the bottom of the main hoop.

K

63242



Nice! That&#39;s pretty much the exact thing I was conjuring up in my head for a "Nascar X".

[Geo]

The only think about an X like that is that you lose all of the advantage of the X. Might as well go all the way with classic NASCAR style door bars.

[Knestis]

Originally posted by Geo@Oct 23 2005, 02:02 AM
The only think about an X like that is that you lose all of the advantage of the X.

How so? Note of course that they are just tacked here and that we&#39;ll be gusseting them much like the last ones.

K

[Geo]

Originally posted by Knestis@Oct 22 2005, 09:12 PM
How so? Note of course that they are just tacked here and that we&#39;ll be gusseting them much like the last ones.

K

63255


The traditional X is torsionally stronger and (IMHO) safer because they traverse the shortest distance between two ponits. To bend them, you must stretch them. Bent tubes like that take far less energy to bend. You are gonig to lose the torsional rigidity with the bent tubes. BTW, by bent I mean bent outward, not bent to meet in the middle on the same plane.

[Knestis]

Ah - gotcha. I will grant that, since they are not straight, they are not as rigid as the same materials and gusseting in a flat plane.

K

[Knestis]

Better shots of what&#39;s going on in the door holes...

http://it2.evaluand.com/gti/images/mk3.2/cage05.jpg

http://it2.evaluand.com/gti/images/mk3.2/cage07.jpg

K

[Knestis]

Here it is, all welded up with taco gussets and stuff. I&#39;m VERY pleased with Chris Schimmel&#39;s most recent creation. You can&#39;t tell from the pics but it is amazing how much roomier it is in there with 1.5" tubing pushed closer to the chassis, and the seat 1" lower than it was.

http://it2.evaluand.com/gti/images/mk3.2/cage08.jpg

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

K

[lateapex911]

Nice bit of kit...

Very well thought out. How many feet of tubing do you have in there?

[Bill Miller]

Nice looking cage for sure! :023:

Kirk,

It&#39;s hard to tell from the updated pictures, but is there a dash bar in that design?

[Knestis]

We elected to not add a dash bar, because of the presence of that massive black-painted structure that bolts across that space. It is essentially trapped between the uprights - though not attached to them, obviously- and is way stouter than a tube would be. I also wasn&#39;t planning on using a dash bar as an excuse to take dash/heaterbox/controls out, like I see some folks do... :)

When things settle down next week, I&#39;m going to do the math and figure out what this one weighs, and compare it to Pablo&#39;s first cage. Should be interesting.

K

[philstireservice]

Originally posted by Knestis@Oct 24 2005, 09:34 PM
Better shots of what&#39;s going on in the door holes...

http://it2.evaluand.com/gti/images/mk3.2/cage05.jpg

http://it2.evaluand.com/gti/images/mk3.2/cage07.jpg

K

63428



Sheeesh !!! finally a decent cage. Not like that "rinky dink" one in Pablo...lol


J/K Kirk.......mmmmmm very sweet....nice nice very nice !!!!

[lateapex911]

Originally posted by Knestis@Nov 2 2005, 10:34 AM
I also wasn&#39;t planning on using a dash bar as an excuse to take dash/heaterbox/controls out, like I see some folks do... :)

K
64286


Grrr...I thought the rule allowed for movement of the controls, not the exclusion of them>?

I hope I am wrong....and if I&#39;m not, I hope everyone who cheats like that has to run in the rain for the rest of thier lives.

[Dave Zaslow]

See post below. Friggin attached images.......

[Dave Zaslow]

Kirk,

On my A3 I did the dash bar following the boxed section under the window as seen below. The stock brace is indeeed a very nice piece that ties the structure together and I was able to just notch a little bit of the ends to fit it. You can see the two holes for the bolts on each end of the tube. This stamped metal composite just did not give me comfort in keeping the the A pillar downtubes and the firewall away from me. This routing also allows the heater box/fan to stay in place. You can get the non-AC parts to attach to the AC heater box (they are the same). The dash and controls, including the stock guage cluster fit right back in.

Dave Z



Originally posted by Knestis@Nov 2 2005, 10:34 AM
We elected to not add a dash bar, because of the presence of that massive black-painted structure that bolts across that space. It is essentially trapped between the uprights - though not attached to them, obviously- and is way stouter than a tube would be. I also wasn&#39;t planning on using a dash bar as an excuse to take dash/heaterbox/controls out, like I see some folks do... :)

When things settle down next week, I&#39;m going to do the math and figure out what this one weighs, and compare it to Pablo&#39;s first cage. Should be interesting.

K

64286

[Knestis]

Sorry - Dave is absolutely correct that it is indeed doable, without taking liberties with the HVAC unit etc. We just didn&#39;t think that it afforded the kind of cost/benefit that a dash bar would in, say, an A1 Rabbit that doesn&#39;t have that huge brace. I&#39;m of the opinion that this one piece accounts for a chunk of the weight difference between a "bare" A2 and an equally naked A3 tub.

K

[WIZARD Racing]

Another late arrival.

To add to the "X" debate:
If I remember right, a lot of the Club Rally cars I&#39;ve seen in the past had "X" bars on both sides. Or they were similar to Kirk&#39;s cage (which looks great).
Shine Racing also used the "X" for thier cars. I saw the &#39;after&#39; of one of the cars at the 1999 ARRC. It was a big hit destroying all ahead of the firewall, but the main cockpit was fine.

[Knestis]

Interesting update...

Calculations indicate that the new rollcage includes 13 feet more tubing that the one it replaces but weighs only 6 pounds more - 109 pounds. This is not counting gussets and mounting plates in both designs, the previous of which had more of both. This, thanks to use of 1.5 rather than 1.75" OD tube.

Approximately 9 pounds were saved using the thinner-wall tubing in optional diagonals, compared to how much it would have weight with .095 wall throughout.

K