7 replies to this topic

[WilsonSteele]

All,
I am in the midst of planning a cage swap from a wrecked tub into a new car, and i wanted to solict advice on this from people who have done it before, especially in a 94.
Any advice appreciated, and especially pictures while you did it.
This is for a lemons car project, so i am open to creativity as well, but i am hoping to wind up with somthing that is mostly a PTE car when done...

[Jim Drago]

I have done this before and works well and pretty easy.

 

First, I assume the old tub is junk, so cut off the windshield frame with a sawzall and throw it away. 

 

Then cut the legs off flush to all the mounting plates

 

Cut the forward braces somewhere ( these will need to be replaced)

 

Cut the down tubes from the main hoop to rear trunk deck ( these will need to be replaced)

 

 

From here the entire cage will lift out

 

While out, use a very thin cut off wheel and cut the welds on the following:

You want to end up with three pieces.. The main hoop, the left and right sides. So you want to cut the welds where the door bars and a pillar bars meet the main hoop. You will allso need to cut the welds on the windshield bar on atleast one side, probably easier to do both. You will be surprised how well this works. When done, you will have three pieces to weld together and add new down tubes. any  and forward braces, 

[Jason J Ball]

When I did mine, I replaced the rear down tubes as well. But I did not remove my door bars from the main hoop. I cut the front down tubes at the top of the main hoop, and then cut the door bars a the down tube. That left me with the dash bar and windshield bar holding the down tubes together and the main hoop with the door bars on each side. I used a plasma to cut all the welds. Be careful when you cut the tubes at the chassis plates, I lost a little height because I didn't cut them as close as I should have.

[KW78]

Honestly,

 

Don't do it.  It just isn't worth it IMO if your time is worth anything at all. 

 

I have done this twice, once in a 94.

 

You do lose height in the main hoop because you can cut it close enough.  If you have a multiplane mounting plate it's really a hack job.  On the second one, I decided to cut around the cage plates and then cut the car up from the outside to the back of the cage plates.  This took forever.  You learn how many layers a tub really has at the rocker panel structure areas.

 

If you don't have multiplane cage plates then it's not a great cage worth saving probably.

 

Remember that there are rules about all the other tubes you cut.  When you put them back together, if you can't re-fishmouth the tubes (which costs you length and changes the fit of every other tube associated with that bar)  you are required to sleeve the joint and rosett weld the sleeve, then weld around the joint.  Maybe a tech inspector doesn't catch it if you don't do it, but that is technically the rule.

 

In the end the time to save the cage versus build/buy a new one wasn't worth it by alot!

 

My .02,

Kyle

 

Edit:

 

Here is why I cut the cage out.  I have purposely forgot the name of the jackass here.  We enjoyed 2 or 3 close laps of swapping positions for like 16th at the runnoffs.  The next group was not possible to reach.  This was last couple of laps of the race or so.

 

I passed him into corner one really late because he pointed me by, and I had help up the front straight.  But, I still blew the exit of 1 so I gave him the apex at 3,and was tracing a slow arc on the dirty outside and got punted anyway.  Corner 3 workers felt it was on purpose, so they started a RFA. 

 

[KW78]

9.4.7

The following procedures are approved for modification to roll bars/cages that do not meet the two (2) inch required minimum: The old main hoop may be cut off near the chassis mounting and a new main hoop of equal tube size or a section of equal tubing size may be added, and inner tube(s) must be used to mate all sections together. All braces must be minimum distance from top of hoop per Section 9.4. All welding for this modification
must be arc welded (min.). The inner tube(s) must be rosette welded three (3) places near top and bottom, see figure 21.

 

Here is a clip from the 07 cage rules, available to use for current cages.  The current rules don't address this it seems, so maybe you can have any joint you want now.....  ??

 

Kyle

 

[LarryKing]

outside and got punted anyway

 

I like the "Hand HANS"

[joeg5982]

You certainly can always add back the tubing you lose at the plates in cutting.

[Jim Drago]

You certainly can always add back the tubing you lose at the plates in cutting.

 

Agreed, also, if you cut at base plate, you should lose less than 1/16- 1/8 in.