After much deliberation, I've finally pulled the plastics and bulkhead out of my car for a roll bar. My fabricator is Tony@TCDesign. Although I have complete confidence in Tony's design, I'm just curious about the variations I've seen (I'm assuming these all pass tech). Would anyone be able to comment on them? I'd really like to understand what is necessary, what is overbuilt, and what is poor design).

Mainly
-Why the variance in where the supports for the main hoop is located?
-Is the design of Si's fabricator valid or overbuilt (in reference to the support mounts in the back)?
-Purpose of jack point in the Racelabz design?
-Any advantage as far as Chromoly vs DOM Steel?

Tony@TC Design
(rob.ok)



(krazik)



Scot's Car (Unknown Fabricator)



Si's Car (Unknown Fabricator)





Izzy's Custom Cages



Racelabz

 

I want to do a rear subframe pickup. Some will argue against it.

 

Steve, I'll be at BW on 4/11 if you want to check it out in person.

I can't give you any details (I totally forget now), but I did talk to Tony about all the different options you are asking about. He was pretty certain that this design was the best so I just let him do his thing. If you ask him about it can can explain why he feels that way.

I also chose the Heavier DOM cause I was worried about the final race weight.

-Rob

Edit: Better Pics....

 

Rob, what dash are you running?

 

Race Technology Dash2 & DL1.


-Rob

 

i was taught that running the main hoops diagonal should be placed not at the corner but a little towards the middle to support the top of the main hoop.. Louie of LCON (prob the most respected cage builder on the west coast) puts them in the corner. his reason was to intersect any possible points at the same point and create triangles. i think both theories make sense. both will support well. there is no real easy way to tell what works better. also, the diagonal creates "hoop like" barrier over the driver. see what i mean here?


chromoly vs DOM.

i use DOM because its easier to work with and meets the rules guidelines. chromoly is superior because it is lighter and arguably stronger then DOM, But it is also more expensive and you will find fewer builders using it because its a much more difficult process and you would need to tig weld the cage.. chromoly cages usually come out looking perfect tho. big difference in price from a DOM cage but maybe worth it.



the only thing i wouldve dont different with your bar is running the rear legs as far back as possible instead of in front of the rear towers. running them further back would also NOT cause them to pinch inwards. im not to found of that design. running the rear legs further back would help save the frame from a rear impact coming further into the car, keeping the car a little more salvageable. this is another theory that has been argued recently. i really doubt that there is much benefit running the legs to the towers.. im just weighing the options. just get a better rear stut bar if you need it.

there is more then just 1 right way to build a cage. the fact is that cage builders are going to build whatever they believe works or whatever they were taught. go with a builder that you trust with your life.. because well.. thats essentially what you are doing

 

Actually, there is. It's called "truss analysis".

 

Since it's so easy do you mind sharing with us the results. I'm sure the S2000 track community would be grateful, knowing their car is that much safer.

 

truss analysis doesnt work in things like roll cages because there are other factors to take into consideration like bad welds or human error as far as placement.

but if you want to run the program go for it

 

I'd pay 100 bux for an analysis. I'm sure you guys would too.
Rob, I like the roll bar, hope to see it 4/11.
Did you try asking your fab guy why he chose to do it that way?
After seeing this, i'm going to ask my guy next time i see him.