Funny car cage or containment seat?

[jl222]

 
  Has anyone seen the problem with the bar coming from the funny car cage to bottom frame rail on pg 25

  fig 1?

                 JL222

[doug]

We are currently having a funny car cage installed with a full containment seat in a '91 Camaro. It's tight but lots of protection. I can post pics as the work progresses.

Here is a Kirkey full containment with a funny car cage.  It is a Gen II Camaro.

[jimmy six]

I don't see any reason why that would not meet an inspetors expectations..JD

[dw230]

John,

That bar was put there by SFI. It is their drawing.

DW

[Bob Drury]

  The bottom of the front hoop at the intersection with the "down tube" at the door looks like a poor design to me.  Even though it is triangulated, the downward force of a roof first impact seems like it leaves that joint with a pretty high stress load.
  At the very least I would add a vertical brace at that point............. it sure can't hurt.......
  I also don't understand the curved joint brace at the front of the door entry.
  I would be the first to admit that I am not qualified to argue with SFI, but they are, afterall, the same organization that now certifies two different rated seat belt's...............  I guess they figure that one is to be half-safe, and the other for really wanting to save your a-s...............
                                                                        Bob

[Dynoroom]

Gussets? pg25

[hotrod]

I also don't understand the curved joint brace at the front of the door entry.

I suspect it is to accomplish one of two objectives, it is to provide some give in the joint in case the main tube weld to the halo bar fails, the two curved gusset bars would have some give in them to use up energy in deformation.

More likely I think it is to avoid a long acute angle where the gusset tube joins the halo bar, giving more access for a more reliable weld on the inside of the gusset tube.

By approaching the upper halo tube more at right angles at the joint the heat affected zone of the weld is smaller as well. If that were a very acute angle joint there would be difficulty both making a sound weld on the inside of the acute angle and visually inspecting that weld. If it were a cold weld the whole tube could just unzip the weld in an impact.

That is just my SWAG on why that feature exists. It would be interesting to get an engineer familiar with the analysis of the design to comment.

[Bob Drury]

  Hotrod, I am not arguing with you, but it seems that the "acute" inside angle would have the thickest metal at the joint, and the heel would be the thinest and therefore weakest part of the joint.............. just my opinion, obviously................  Bob

[Tman]

Bob, the curved "gussett" at the top of the A pillar looks like somebody gettting cute and artistic. I may be new to LSR but have been around many cages. Enjoyed the brief meeting at the Salt Talks!

[Cajun Kid]

It could also serve double duty as a tubular gusset and a grab handle so the driver can have a place to grab on for exit.

Just my thoughts.

Charles

[jl222]

 
  Has anyone seen the problem with the bar coming from the funny car cage to bottom frame rail on pg 25

  fig 1?

                 JL222

 I should have said problems [ bob's problems are why I'm waiting to now to point this out] the problem I was trying to point out was the bottom right side tube on funny car cage crossing over to left bottom frame rail [were can one's
legs go? Also cross bar behind seat should be higher to attach seat belts and tube across front of chassis should connect at same point as on left our bellhousing will not clear.

  I pity anyone trying to build a cage to these S.C.T.A. [in rule book] drawings and they should be inproved for next year and I'm sure they will be after SCTA becoming aware of short comings


                   JL222

[Bob Drury]

  I just noticed in the second picture a vertical from the "x" intersection at mid-door which drops to I believe the main frame rail.  I think that would take the place of my suggested vertical brace.
  I am not if favor of the "pro stock/pro mod inner hoop kickback as it drops over the trans tunnel.
  Every time I look at those, I think a good seat and a 12 or 14 point cage should be stronger.

[Tman]

It could also serve double duty as a tubular gusset and a grab handle so the driver can have a place to grab on for exit.

Just my thoughts.

Charles

I thought that as well Charles. Watched Nexussian rig up something similar to get out of the berkley

[dw230]

"  I pity anyone trying to build a cage to these S.C.T.A. (SFI) [in rule book] drawings ..."

John,

Maybe you should contact SFI and have them change their cage specs. Carl Olsen would be a good start.

DW

[jl222]

"  I pity anyone trying to build a cage to these S.C.T.A. (SFI) [in rule book] drawings ..."

John,

Maybe you should contact SFI and have them change their cage specs. Carl Olsen would be a good start.

DW

  Well someone should, and ask for structural engineering and the name of the guy [ maybe secretary] that drew them.

   JL222