Interior cage tie-in

[XJJPR]

XJGuy said:
There are areas on the XJ floor that have major structural strength without necessitating "frame" tie in.

I'm staying out of the cage part with Sean, Beezil and you but this statement is very missleading. Other than directly above the frame section of the unibody, where is an XJ floor pan have any strength at all? It has to be the weakest part of the entire XJ. All it is worth is keeping your feet from dragging on the ground. You can't really be saying the floor pan of a XJ is strong and worth betting your life on.

And saying your adding vertical gussets doesn't support the notion the floor pan as being strong.

mark
orgs mfg

 

[XJZ]

Mark said:" It has to be the weakest part of the entire XJ. All it is worth is keeping your feet from dragging on the ground.

I have to disagree, it also holds the carpet in.

 

[XJguy]

Mark, an example of what I am saying is the floor pan immediatly adjacent to the rocker; this area is very structurally sound. Another area, the rear wheel well, the round shape adds to the strength like an egg. There are other areas where intersecting body panels offer great strength as a result of triangulation, just look at it as a frame but on the inside. Adding gussets or even a plate that is L-shaped gives you one more plane by which to attatch the plate. Bottom line is you have to spread the load, multiple points, that way even if one does mange to punch through you dont get crushed because the other 9 are still where they should be; same goes for stiffening of the chassis.

By they way, the roof, fenders and doors I feel are much weaker not enough angles (triangles) or contours...heh heh

XJguy

 

[Beezil]

xj guy said: "strength like an egg"



Oh shit, here we go........

 

[XJJPR]

JXguy,

But once you've moved over to the rocker area you're not talking about the floor pan. You're talking about the rocker's edge. I'm just saying that if you state the floor pan is strong it really missleads. The floor pan is the thinest material used on the XJ. As for thinking the rear wheel wells as being strong you need to do more reserch. I have found them to be quit weak and have destroyed them with very little effort.

The one point we will always agree on is on an XJ load forces MUST be spread out to be effective. Hope to see this cage of yours soon, I'm sure lots of people are waiting for it.

mark
orgs mfg

 

[XJguy]

xj guy said: "strength like an egg"



Oh shit, here we go........

LOL :roflmao:

Mark, youre right, I guess it is a bit misleading but then again I am assuming that someone who would build a cage would not just stick a tube randomlyand end up mounting to the weakest areas of the floor (you know what happens when you assume). Well we get back to what I suggested to Fergie early on..gotta do the research, books, pictures, people who know, and the web.

Rear wheel well, try bending them from above square on, then try doing it with a 3/16" 6x6 plate welded to it.....it aint happening.

XJguy

 

[XJJPR]

LOL :roflmao:



Rear wheel well, try bending them from above square on, then try doing it with a 3/16" 6x6 plate welded to it.....it aint happening.

XJguy

I can make anything strong with 3/16' plate and my welder. LOL


mark
orgs mfg

 

[MistWolf]

What I was trying to explain is the ultimate job of a cage to stiffen the chassis- heck the job if the chassis itself- is to fix the mounting points of the suspension and eliminate any flexing between those points. If you can build the cage so it does that you're golden. You may not have to tie directly to the mounting points themselves.

Many of the fast Mustangers use subframe connectors to stiffen the chassis, sometimes cutting a section out of the floor and running it partially inside the passenger compartment.

I agree with mounting the cage to the seatbelt mounts on the pillar. That's a hard point. I also think tieing into the subframe connector is a good idea. I have replaced my rocker panels with steel tubing. If I jack up my XJ using the replacement rocker panels, the front will sag and distort the door opening and make it hard to open the door.

One experienced body man explained to me that A and B and C pillars denote strucural strength, not pillar location. A pillars are primary structers, B pillars are secondary structures and C pillars are tertiary structures. He told me the rocker panels are B pillars. I do know that my rockers would be stronger if I tied them into the subframe.

I have often heard folks claim that unibodies have no frame. This is false. The unibody IS the frame. Unibodies are taken from aircraft semi-monoqoque designs which are made up of bulkheads, ribs, longerons, stringers and stressed skins. All of these parts make up the airframe just as they make up the frame of our XJs