Drill holes in floor and drop threw so you can have a flat plate on the floor OR build up on a box which do you guys think is stronger?

 

the plates on the floor are stronger then most of the box's you see.

If you were looking at reneM's car, those box's IM(unproffessional)O are wayyyyyyyyyy to big.


I have seen "box's" done other ways, and i like it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slammed_93_hatch &raquo;</TD></TR><TR><TD CLASS="quote">the plates on the floor are stronger then most of the box's you see.

If you were looking at reneM's car, those box's IM(unproffessional)O are wayyyyyyyyyy to big.


I have seen "box's" done other ways, and i like it.</TD></TR></TABLE>

I have also built rally cars that have taken on rather large trees in to the drivers door and finished the race, how about you?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rene M &raquo;</TD></TR><TR><TD CLASS="quote">

I have also built rally cars that have taken on rather large trees in to the drivers door and finished the race, how about you? </TD></TR></TABLE>

Maybe so, but it might not have anything to do with your plates or boxing system. Building a roll cage is a compromise between building it strong enough for driver (and in the case of rallying, the co-driver) to survive uninjured and building it too stiff where little energy is absorded in the collision. It has to be strong enough where the general integrity of the cage is intact with only a small amount of deformation to avoid contacting the drivers appendages or other soft tissue. Too stiff, and the driver might experience large enough accelerative forces to cause brain injury or other types of soft tissue damage.

Unfortunately, many (not all) fabricators build cages too stiff or they run sections of tubing eccentric to the preferred load path. In either case, the cage in sub optimal for the task of protecting the driver. In addition, it is very difficult if not impossible to build a cage to withstand any type of collision. If you happen to spin out and also unluckily expose your drivers side in a blind and fast spot of the track with a 3000 lb + AIX car bearing down on you at 120+, then you might be out of luck. With good engineering and good fabrication, a great and safe cage can be built for the large majority of impacts or rollovers.

 

yeah it just seems to me the the box could collaspe where if its plated to the floor there is no way for it to collaspe.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ekim952522000 &raquo;</TD></TR><TR><TD CLASS="quote">yeah it just seems to me the the box could collaspe where if its plated to the floor there is no way for it to collaspe.</TD></TR></TABLE>

It could, however, tear out the floor...

Is there enough meat in the sills or equivalent areas on our cars to tie the cage into there? I know that in my "other car" world, having a cage mount to the sheet-metal floor pan is a real no-no, because the sills are nice box-section pieces that can take (and transfer) a lot of loading, and they are not that hard to mount the cage feet to.

--DD

 

My dad and I just welded in a four point kirkey bar. What we did was made larger plates, and welded it into the three sides in the corner. So, one on the bottom, one on the back where the rear seat goes, and one to the side/rocker. Then put the rollbar plate and welded it there. We thought about then boxing it in. I would think that way would be plenty strong. But by no means am i a proffessional

 

I can only speak from my personal experience but 3 sided plates seem to work just fine. We drilled holes in the floor to allow the cage to be lowered. It saved my bacon a couple of weeks ago

Inside view:
http://jellybeanracing.com/Joh...h.wmv

External view:
http://jellybeanracing.com/Joh...f.wmv

(please right click and save target as)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by coneheadsracing &raquo;</TD></TR><TR><TD CLASS="quote">My dad and I just welded in a four point kirkey bar. What we did was made larger plates, and welded it into the three sides in the corner. So, one on the bottom, one on the back where the rear seat goes, and one to the side/rocker. Then put the rollbar plate and welded it there. We thought about then boxing it in. I would think that way would be plenty strong. But by no means am i a proffessional </TD></TR></TABLE>

That method is fine for what you were doing, but they are talking about a custom cage where you need 360* welds, yet still want it as close to the roof/a pillars as possible. So the 2 options presented are to either cut holes in the floor to drop the cage down enough so that you can weld on top of the tubing, then raise it back up and cover the holes with plates, or to make the legs shorter and once you've done the 360* welds, put it up on boxes to get the extra height back.

IM(also unprofessional)O, they're both proven methods that have been crash-tested over many years. I don't really worry about 6" x 10" plates welded to both sides of the floor pan ripping through it, yet welding to the frame rails (box method) defintely seems like a good idea. The plate method doesn't take up as much room and you can still stand a plate up to the frame rail to tie it in if you want to.

- Scott

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rene M &raquo;</TD></TR><TR><TD CLASS="quote">

I have also built rally cars that have taken on rather large trees in to the drivers door and finished the race, how about you? </TD></TR></TABLE>

never built a car that has crashed. But i have heard, and tend to agree with, what i wrote above, from some knowledgeable people.

But really you should calm down, it was just MO. I see bigger issues with your cage then the box's.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rene M &raquo;</TD></TR><TR><TD CLASS="quote">

I have also built rally cars that have taken on rather large trees in to the drivers door and finished the race, how about you? </TD></TR></TABLE>

The shop that built my cage built pretty much all of Alara Racing's SPECMiata cages, and he uses the plate method exclusively. He's been building cages for a long time, so I trust his judgement. My cage uses the plates. Lucas Automotive is the name of the place, case you want to give them a buzz.

 

i dunno. to me (unprofessional), those sharp boxes look like big ankle/leg choppers. i guess you have more to worry about in a big wreck, but i think i'd like a padded tube than a pointy box.

 

Bottom line is this, what are you attaching your plate or box to? That really is the key. You want your 'base' to be tied in to a strong point on the unibody.

 

so if i build cages for twenty years with absolutley no engineering knowledge what so ever; but great fabrication you will trust me? kind of naive......

I'm not an engineer but on my way to be one. If i can;t answer a question or design something safe i consult the people that are smart enough too.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ekasey &raquo;</TD></TR><TR><TD CLASS="quote">so if i build cages for twenty years with absolutley no engineering knowledge what so ever; but great fabrication you will trust me? kind of naive......

I'm not an engineer but on my way to be one. If i can;t answer a question or design something safe i consult the people that are smart enough too.</TD></TR></TABLE>

Given that he was building cages for Motorola Cup cars (years ago), I'd tend to trust him. does he have any degrees that says he's an engineer? I don't know, but, when the TX region NASA director wanted a cage for his STI, that's who he went to as well. Maybe you should call him directly to find out his credientials, 713-462-0068, Greg is his name.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DavidR &raquo;</TD></TR><TR><TD CLASS="quote">

Given that he was building cages for Motorola Cup cars (years ago), I'd tend to trust him. does he have any degrees that says he's an engineer? I don't know, but, when the TX region NASA director wanted a cage for his STI, that's who he went to as well. Maybe you should call him directly to find out his credientials, 713-462-0068, Greg is his name. </TD></TR></TABLE>

I think your missing my point.....

Engineer designs the cage, fabricator builds it.

Plus I have a fabricator

If I did live in Texas I know I would go to T1 Race Development

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ekasey &raquo;</TD></TR><TR><TD CLASS="quote">

I think your missing my point.....

Engineer designs the cage, fabricator builds it.

Plus I have a fabricator

</TD></TR></TABLE>

So you are saying an engineer can't fab, or a fabricator can't Engineer?

Did you call Greg to get his background? I trusted his work after several recomendations from fellow racers, as well as the 5-6 SPEC-Miata cages he does a month... he's got to be doing something right to be keeping that kind of business.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DavidR &raquo;</TD></TR><TR><TD CLASS="quote">

So you are saying an engineer can't fab, or a fabricator can't Engineer?

Did you call Greg to get his background? I trusted his work after several recomendations from fellow racers, as well as the 5-6 SPEC-Miata cages he does a month... he's got to be doing something right to be keeping that kind of business. </TD></TR></TABLE>

Generally, engineers and fabricators are distinct people. A good fabricator would hopefully have sought the advice of the proper engineer for his structural work. Not just any engineer knows the correct way to do structures.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DavidR &raquo;</TD></TR><TR><TD CLASS="quote">

... he's got to be doing something right to be keeping that kind of business. </TD></TR></TABLE>

Not necessarily, you can repeat and do the same things wrong for twenty or more years if you are lucky without really knowing why. Sometimes, you aren't so lucky and you have a problem. Not to point fingers, but the Factory Five's cages are pretty bad in my opinion and I'm not surprised that someone was killed in one right in front of my eyes earlier this year. So it means nothing that someone has built twenty or fifty or even a hundred cages when none of these cars have been in a many incident. This is not saying he doesn't build the best cages in the world, it's only to say that you argument about the number cages built doesn't mean the cages are good.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Johnny Mac &raquo;</TD></TR><TR><TD CLASS="quote">

Generally, engineers and fabricators are distinct people. A good fabricator would hopefully have sought the advice of the proper engineer for his structural work. Not just any engineer knows the correct way to do structures.

Not necessarily, you can repeat and do the same things wrong for twenty or more years if you are lucky without really knowing why. Sometimes, you aren't so lucky and you have a problem. Not to point fingers, but the Factory Five's cages are pretty bad in my opinion and I'm not surprised that someone was killed in one right in front of my eyes earlier this year. So it means nothing that someone has built twenty or fifty or even a hundred cages when none of these cars have been in a many incident. This is not saying he doesn't build the best cages in the world, it's only to say that you argument about the number cages built doesn't mean the cages are good.

</TD></TR></TABLE>

well, does someone bringing him a new chassis to weld a cage into after they've totalled the previous one say he'd be any good? Maybe they just liked the way his colonge smelled.

 

your sticking up for some one, who again IMO, missed some very basics of cage building. Getting past the whole box thing, he didn't even think about the 190 degree, or the maximum attachment points.


Bottom line is it is his car, and as long as anyone who drives it feels safe, then that is fine. The cage in my car has a a defferent design, some people like it, some don't. I feel very safe in it, and thats all that matters. And if some one askes why i did what i did, i actually have a reason. Not "well i looked at 1000000 cages and that makes me an expert on cage design.

Plus his attitude, pretty much sucked. I gave my OPINION earlier, and he took it like an attack.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slammed_93_hatch &raquo;</TD></TR><TR><TD CLASS="quote">your sticking up for some one, who again IMO, missed some very basics of cage building. Getting past the whole box thing, he didn't even think about the 190 degree, or the maximum attachment points.


Bottom line is it is his car, and as long as anyone who drives it feels safe, then that is fine. The cage in my car has a a defferent design, some people like it, some don't. I feel very safe in it, and thats all that matters. And if some one askes why i did what i did, i actually have a reason. Not "well i looked at 1000000 cages and that makes me an expert on cage design.

Plus his attitude, pretty much sucked. I gave my OPINION earlier, and he took it like an attack.</TD></TR></TABLE>

I wasn't sticking up for Rene's car, I was sticking up for Lucas Automotive, who built my cage. I didn't like the boxes, niether did Greg at Lucas. When I explained to him about "fully welded" he chuckeled and said the boxes were more of a liability than not getting that last 1/8 around the pipe, which, can be gusseted for strength anyway. He laughed even harder when I mentioned cutting the roof off to fully weld it....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DavidR &raquo;</TD></TR><TR><TD CLASS="quote">

well, does someone bringing him a new chassis to weld a cage into after they've totalled the previous one say he'd be any good? Maybe they just liked the way his colonge smelled. </TD></TR></TABLE>

David, I recommend a college course in logic for you since each point you've made so far is fallacious from a logical point of view (the above comment by you qualifies as a fallacy based on "appeal to an unauthorized authority" referring to the guy who brought his car back to the original builder). I could go on, but I really don't need to belabor the point about how to build a good cage requires both fabrication and engineering knowledge. I could also care less that anything I've said to you so far has gotten you to think about how cages (actually frame structures) work or don't work. You keep giving irrelevant arguments about why someone who totals his car brings it back to the guy who built the first one. Maybe he didn't hit something hard enough or in the right place, eventhough the car was totaled, to find the weakness in the cage.

I don't claim to know everything, but I have quite a bit of experience with frame structures. I worked on fatigue and strength critical tail frame and landing gear structures for Robinson Helicopter for four years. Before that, I designed and engineered steel trusses for homes and commercial for Angeles Metal Systems for a number of years.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Johnny Mac &raquo;</TD></TR><TR><TD CLASS="quote">

David, I recommend a college course in logic for you since each point you've made so far is fallacious from a logical point of view (the above comment by you qualifies as a fallacy based on "appeal to an unauthorized authority" referring to the guy who brought his car back to the original builder). I could go on, but I really don't need to belabor the point about how to build a good cage requires both fabrication and engineering knowledge. I could also care less that anything I've said to you so far has gotten you to think about how cages (actually frame structures) work or don't work. You keep giving irrelevant arguments about why someone who totals his car brings it back to the guy who built the first one. Maybe he didn't hit something hard enough or in the right place, eventhough the car was totaled, to find the weakness in the cage.

I don't claim to know everything, but I have quite a bit of experience with frame structures. I worked on fatigue and strength critical tail frame and landing gear structures for Robinson Helicopter for four years. Before that, I designed and engineered steel trusses for homes and commercial for Angeles Metal Systems for a number of years. </TD></TR></TABLE>

BUT OMG you haven't even built a cage how could you know anything? This guy has been doing it for 25 years he pwns j00 OMGZ0RZ

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ekasey &raquo;</TD></TR><TR><TD CLASS="quote">

BUT OMG you haven't even built a cage how could you know anything? This guy has been doing it for 25 years he pwns j00 OMGZ0RZ</TD></TR></TABLE>

I haven't built a cage is for sure, but I can dream about how it should go together, does that count?

At Robinson, the welders (TIG) and I got along great when I would come around and discuss the location and the placement of tubes and welds and sizes of beads and all of that. They knew their stuff and I knew my mine and it was a great marriage of sorts. Too bad we don't see more collaboration between the experts in their individual fields in the racing cage business.


Modified by Johnny Mac at 1:28 AM 8/18/2006

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Johnny Mac &raquo;</TD></TR><TR><TD CLASS="quote">

I haven't built a cage is for sure, but I can dream about how it should go together, does that count? </TD></TR></TABLE>

Only if you stayed at a Holliday Inn Express last night..