Main Hoop Braces/Bulkhead interpretations

Greg, I have no personal issue in this so you can do as you like. I think if written up correctly I could win a protest..that was the point. I also will say that letters from the tech dept mean nothing. Anyway i am not interested in an argument so we can agree to disagree.

As far as the strut brace being part of the cage it is clearly put there to stiffen a suspension point (shock mount) and could have been put between the 2 tubes so it was an integral part of the cage.

Joe


[This message has been edited by Joe Harlan (edited January 07, 2005).]
 
Well, as I'm fond of saying, if it says you can, you bloody well can. Greg has reprinted the exact words that say you can.


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George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com
 
This as well as other bars to the front firewall mounting points were protested on the Speedsource cars at the ARRC in the past and found legal. Great cage!! Those that complain should copy if you think it is an advantage. You just got a free seminar on grey areas.
 
Well know there you go. I made it very clear it made little difference to me and I certainly was not complaining. I learned nothing I didn't already know and you make the key point. Those that feel its an advantage. Well fact is it isn't and I can get to the same place without getting into the grey area....Its been fun.
 
Boy, after looking at this thread I can't imagine anybody would be turned off by the SCCA (tongue firmly in cheek).

If you still need more closure on this....
Here's a picture of one of our SS cars when we first got it (it used to be a driver training car):
http://img1.exs.cx/img1/8788/rearplate3xy.jpg

We were concern about it being interpeted as suspension reinforcement (as well as a couple other areas of the pre-existing cage), so we sent a photos to the Club Racing Technical Manager and received a written response that it's OK. First season we carried that around with us in case someone complained.

How about arguing about something that makes a difference?

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Jeremy Lucas
Team Honda Research
Kumho - Cobalt - Comptech
 
Originally posted by seckerich:
This as well as other bars to the front firewall mounting points were protested on the Speedsource cars at the ARRC in the past and found legal. Great cage!! Those that complain should copy if you think it is an advantage. You just got a free seminar on grey areas.
Click to expand...

One thing in the specific case we have been discussing that cannot be gotten around is the dimensions of the mounting plate. Granted we don't have a ruler in the photo, but I'd bet money that it exceeds 12" in length and that is strictly illegal if it is.

Then there is the gutting of the passenger door, the removal of the radio wiring, etc. Of course, those are not strictly cage related.


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George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com
 
George you are correct about the plate and door bars. The plates on this car are evidently covered by previous logbook and would not be legal in a new car. The plates can be 100 square inches total with the stated 12 max and min 2 restrictions. It can however look like an L shape with 2 12 by 2 legs in different directions and is encouraged to extend to vertical surfaces for strength. This is stretching the rule to the max, but it is the max for a reason. The grey area I was speaking about is the ever present "perform no ilegal operation" and gets the usual vague response. A cage is meant to strengthen the structure of the car and the fact that mounting points are required in the rear at or near the strut or shock towers is equal for all and should be taken advantage of by all. I have seen the rear section of a cage ripped loose from a plate that was attached to the floor above the frame rail only. I will however skip the long and painful wrestle over the radio harness and agree to disagree!!
 
"The "rearmost horizontal cage stiffening brace", which just so happens to do a very good job of bracing the rear strut towers, has been defined as probably technically illegal but too gray to push. I asked the question several years ago. I believe the trigger for the inquiry was a certain ITS RX-7 out of Memphis."

Norm, I assume you mean my old car - I don't recall being aware that there was a big issue of the strut tower stiffening; I thought the issue was w/ the fact that the cage builder had cut away the speaker enclosure to put his mounting plate right on top of the tower itself. It got by because somewhere it says you can cut pretty much whatever you need to install your cage.

I think Greg hit the nail on the head - we all know very well that people spend big bucks on chassis-stiffening cages, and there is nothing wrong w/ that even though the cage clearly performs another function. The free allowance of other tubes w/i the cage is a suggestion that we are not going to nitpick cages and ask "is this for safety or some other purpose" about every additional tube.

I have an early SpeedSource car and am looking at a photo of the "Evo" cage in Wade Williams' later SS car and neither has any attachment to the shock tower. There is a tube connecting the floor-mounted braces.

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Bill Denton
87/89 ITS RX-7
02 Audi TT225QC
95 Tahoe
Memphis
 
<font face=\"Verdana, Arial\" size=\"2\">Originally posted by seckerich: It can however look like an L shape with 2 12 by 2 legs in different directions</font>
Click to expand...

I have to disagree w/ this. If your plate measures 12" in one direction, you're limited to 8.25" in the other direction (12x8.25=100).

Joe,

I understand your point about multi-piece plates, and will even concede that it's probably ok. However, there's no need to 'shout me down' about it. Present a logical reason as to why it falls w/in the rules.

I suppose I need to think outside the box sometimes. I was looking at it as the plate had to be assembled before it was attached to the car, not that it could be installed in pieces.

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608
 
Originally posted by bldn10:
Norm, I assume you mean my old car - I don't recall being aware that there was a big issue of the strut tower stiffening; . . ..
Click to expand...

I don't remember either. It was either your old car or Joe Holley's.
 
Originally posted by Bill Miller:
I have to disagree w/ this. If your plate measures 12" in one direction, you're limited to 8.25" in the other direction (12x8.25=100).
Click to expand...

Your math is wrong Bill. An 'L' shaped plate that is 12" on each side but only 2" wide would be legal since you wind up with 44 quare inches of plate surface.
[(12"x12") - (10"x10")] = 44in2. You forgot to subtract the 10" x 10" hole.

This would be less than the 100 inch max limit.
 
Joe,

I understand your point about multi-piece plates, and will even concede that it's probably ok. However, there's no need to 'shout me down' about it. Present a logical reason as to why it falls w/in the rules.
Click to expand...

I don't think I did and it was never my intent.
 
Bill, I have to disagree with you; I think your position is incorrect.

First, you are assuming the plate must be a parallelogram (i.e., a rectangle). There is nothing in the rules that requires this, nor anything that limits that 100sq-in plate to any number of sides, let alone four. There's not even an implication that only four sides is allowed, nor anything to demand any particular shape.

Second, let's clarify your point of "multiple plates." Nothing in the rules allows "multiple plates." I think what you mean is 'multiple plates that have been welded together to create a single multi-angle plate'. Any first-year welding student can attest to the fact that two properly welded parts are, de facto, one part. In fact, the weld is usually stronger than any other area of the part.

Third, multi-angle plates are specifically allowed by GCR 18.2.8.D: "The mounting plate may be multi-angled but must not exceed these dimensions in a flat plane."

<font face=\"Verdana, Arial\" size=\"2\">[I was looking at it as the plate had to be assembled before it was attached to the car, not that it could be installed in pieces.</font>
Click to expand...

I can understand how you got there, but I don't see how it's required. Honestly, BIll, in reference to the mounting plates, I think all these examples are legal. - GA
 
Originally posted by seckerich:
George you are correct about the plate and door bars. The plates on this car are evidently covered by previous logbook and would not be legal in a new car.
Click to expand...

I don't see how this can work. The rule is very specific. There is no mention of grandfathering. Can you elaborate?

Originally posted by seckerich:
The plates can be 100 square inches total with the stated 12 max and min 2 restrictions. It can however look like an L shape with 2 12 by 2 legs in different directions and is encouraged to extend to vertical surfaces for strength.
Click to expand...

If I lay a tape measure along the long legs (of which there are 2) the length will be more than 12". Just because they are opposite sides of a "T" doesn't mean you count them separately.

Originally posted by seckerich:
The grey area I was speaking about is the ever present "perform no ilegal operation" and gets the usual vague response. A cage is meant to strengthen the structure of the car...
Click to expand...

I have no problem with that.

In the interest of not going down some sidetrack with a big argument, I won't get into the radio harness (which isn't attached to the radio
wink.gif
).


------------------
George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com
 
Multi-angled X-Y-Z axis mounting plates - I have mounting plates in a Spec Miata that look like a 3-D relief map of a Congressional District in the Rockies. Nobody (SCCA Pro, a couple of Club Nat'l Tech Chiefs, etc.) has any problem with that. Why ? Because the rules say you can do it.

Additional tubing that might or might not serve as chassis stiffening/strut bar stuff - 17.1.4.D.10.a.5 (really...) says "...any number of additional reinforcing bars ARE PERMITTED WITHIN THE STRUCTURE OF THE CAGE...blah blah blah quack quack quack." So...no matter the INTENT, no matter the additional benefits it might provide, the GCR specifically allows ANY (!!!!!) additional reinforcement, as long as it's "within the structure of the cage".

It says you can do it.
 
Your math is wrong Bill. An 'L' shaped plate that is 12" on each side but only 2" wide would be legal since you wind up with 44 quare inches of plate surface.
[(12"x12") - (10"x10")] = 44in2. You forgot to subtract the 10" x 10" hole.

This would be less than the 100 inch max limit.
Click to expand...


Greg and Greg,

If you look back a few posts, I stated that I didn't believe it was allowable to 'subtract' the metal that is not there, from the total area defined by the max. X and Y dimensions. As George said, you can't measure the two legs seperately. Greg (Gauper), by your logic, I could take a 12x12 plate, cut a 8x8 plate out of the middle, and then use that as a legal plate (total in. sq. of remaining plate material is 80, ((12x2)+(12x2)+(8x2)+(8x2)) = 80).

I don't believe this to be the intent of the rule nor do I believe it to be legal.

As far as where the tubes attach to a legal plate, I guess that's pretty much wide open. As Greg's pictures show, the tubes don't have to touch. In Kirk's example, it does appear that part of the rear stay contacts the plate, so more than likely, it's legal. If they (rear stays) only contacted the cross bar, I would say that would not be legal, as well as not being a very sound design.

Interesting side note about multiple tubes going to one plate. On my old IT car, I had to pull out a GCR and show the tech inspector that it was in fact legal to have multiple tubes attached to a single plate, and have it considered one point. He was adament that it was not legal, was not going to issue a tech sticker, and was going to make a notation in the log book.

/edit/ corrected 10x10 to 8x8. Had 10x10 on the brain from the earlier part of the post.
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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

[This message has been edited by Bill Miller (edited January 09, 2005).]
 
Originally posted by Bill Miller:
If you look back a few posts, I stated that I didn't believe it was allowable to 'subtract' the metal that is not there, from the total area defined by the max. X and Y dimensions. As George said, you can't measure the two legs seperately. Greg (Gauper), by your logic, I could take a 12x12 plate, cut a 10x10 plate out of the middle, and then use that as a legal plate (total in. sq. of remaining plate material is 80, ((12x2)+(12x2)+(8x2)+(8x2)) = 80).

I don't believe this to be the intent of the rule nor do I believe it to be legal.
Click to expand...

Intent is unimportant. Regardless, what Greg and Greg have said is correct. You can indeed start with a 12x12 plate as long as you remove 44 sq in from the original plate before attaching to the car. The maximum dimension in any direction is 12" thus both the X and Y axis may be 12" as long as the total area is 100 sq in or less.

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George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com

[This message has been edited by Geo (edited January 09, 2005).]
 
Any chassis stiffening arguements are huge red herrings. OF COURSE it stiffens the chassis.

It's OK to stiffen the car in bending moment but not between the two shock towers?

It's fine to tie the front and rear downtubes together in an X pattern in the door, but not cool to add torsional rigidity?

Where and how will you draw the line in such a judgement?? EVERY tube in the cage can be viewed as adding "additional benefits"!

The rules makers knew darn well about the aditional strenthening, and set limits in the design of the rules. If you can get more from the plate rules, good on ya!

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]
 
Well said jake!! You took the words right off of my keyboard...I don't see how it's possible to install a proper "safe" cage without stiffening a unibody and not compromise handling
smile.gif
 
/edit/ Never mind George, you've obviously got all the answers.
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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608

[This message has been edited by Bill Miller (edited January 09, 2005).]
 
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