are there any scca/nasa rules regarding these arms?

 

Nasa Rules:
15�6�11 Rear Braces
The main hoop must have two (2) braces extending to the rear. The braces shall be
attached as near as possible to the top of the main hoop, and no more than six (6)
inches below the top. The braces must not contain any bends*. There must be at
least 30 degrees between the plane of the main hoop and the plane of the rear braces.
The main hoop rear braces shall be installed to form no more than a one hundred five
(105) degree angle or no less than a seventy-five (75) degree angle with the main hoop
when viewed from the top. The main hoop braces may be mounted at the rear shock
mounts or suspension pickup points (providing that the braces remain in compliance with
all other sections of the CCR). They may go through any rear bulkhead(s) provided the
bulkhead(s) is sealed around the cage braces. *There may be certain exceptions
allowed for cars that cannot possible meet this “no bend” requirement. One exception is
listed [Ref15.6.11.A)]. Other exceptions may be made (not guaranteed) if all of the
required bars meet the specifications for a vehicle in the next heavier weight
classification and the alternative design is submitted to the NASA National Office for
special allowance.

SCCA rules:
Cars must have 2 braces extending to the rear from the main hoop and attaching to the frame or chassis. Braces must be attached as possible to the top of the main hoop (not more than 6inches below the top), and at an included angle of at least 30 degrees.

I think both styles meet both orgz

 

like i said, there is more than 1 way to build a proper cage per the rules.. theres really no serious builder who will build something that doesnt comply with the rules. its mostly common sense anyways.

 

haha yes it is!

 

Actually I don't remember why Tony felt that way..... He was totally willing to do it anyway that I wanted, and I asked about all kinds of different options / placement. After hearing his thoughts, I just let him do his thing. I have total faith and trust in the build and it meets / exceeds all requirements to be SCCA legal. I'll be going back to TC Design to finish the cage soon so I can go W2W Tony has also done a number of s2ks so he has worked out all the bugs and thoroughly thought it through.

I thought having the rear stays further back in the trunk area would be better (and easier to mount a fuel cell), but he didn't think so... I believe it had something to do with the frame rails and the way the sub-frame is mounted. I'll crawl under the car and take a better look and see if I can get some photos of that area. It's probably something that we take for granted, yet my fabricator sees it with a different understanding. Maybe it has something to do with there being holes drilled through the frame rails to mount the sub-frame??



-Rob

 

I think you underestimate the going rate for hiring engineers.

But I'll point you in the right direction -- look around at some bridges or powerline towers or even up in your attic at your roof trusses. Check out what percentage of them have the truss members attached such that they form triangles.

 

Mistakes in fabrication don't invalidate design. They only invalidate the fabrication.

On the other hand, designs that cannot be fabricated without making mistakes do invalidate the design, but that's not what you are talking about here.

 

I think I choose the wrong profession

 

I've already posted a lot of my ideas about roll bars. Feel free to search for them.

 

I'll get better clarification tomorrow. Dropped the car off tonight. I need to run back in the morning because I forgot a few things, but it will give me an opportunity to talk to Tony.

Mike: I'll def do a search. Thanks.
EDIT: I'm sure you're aware that our search is garbage but is this what you are referring to?
https://www.s2ki.com/forums/index.php?showtopic=640988