Roll Cage Mounting Plates

[P.Po]

Racers,

I have a few questions regarding the preparation of a roll cage.

The rules state:

"Mounting plates shall be no thinner than 1/8in and no thicker than 3/16in with no single edge longer than 6in and with back-up plates of equal size and thickness on the opposite side of the panel with the plates through-bolted together using a minimum of three bolts per mounting plate. The minimum acceptable bolts shall be SAE Grade 5 of 3/8in diameter. Mounting plates may be welded to the car. Wherever possible the mounting plate should be shaped to and welded to a vertical portion of the car. Mounting plates shall not penetrate the firewall at any point. When the roll cage is attached to the floor, no contact plate on the Car shall measure less than 20 sq. in on any given plane."

Does this mean that you require bolts for your mounting plates even if you do weld the mounting plates?

If the cage is not welded to the floor, but rather a "frame like" structure of the Unibody, do you still require the 20 sq. in of mounting plate?

Thanks for any help...

regards,
Patrick

[ADAM]

its either welded (preferable) or bolted.. not both

[ADAM]

i use 6x6 square mild steel plates as backing plates

[DEK]

Patrick, mounted plates may be either bolted or welded. Both is OK. We have cars where the cage was originally installed as removeable and has since been welded. No problem. Regarding the 20 Sq. In. for mounting plates, if the mounting plates are on the floor, each of the minumum six plates on the floor must be at least 20 Sq. in. I like to see all the mounting plates in a unibody car at least 20 sq. in. even if they are not on what someone might call the floor. For example, if the metal one of the required roll cage tubes is attached to is the same piece of metal as the floor, but not specifically the floor, NOT using a mounting plates seriously compromizes the support given to that tube.
Dave King
CASC-OR Region Chief Scrutineer

[P.Po]

Thanks for the responses Dave, and Adam.

Dave I agree with you that the mounting plate should be present and at least 20 sq in for all points of the cage. The issue is that I purchased a Porsche Club race car (with log book) that I want to run in CASC, but the mounting plates are tiny for the main hoop. I was not pleased when I saw this. The other points are acceptable. (The cage overall has some very good features and some bad features.)

How difficult would it be to replace a tiny or non-existing mounting plate? I suspect it would not be that difficult. Any thoughts or opinions??

[ScotcH]

Originally Posted by P.Po

Thanks for the responses Dave, and Adam.

Dave I agree with you that the mounting plate should be present and at least 20 sq in for all points of the cage. The issue is that I purchased a Porsche Club race car (with log book) that I want to run in CASC, but the mounting plates are tiny for the main hoop. I was not pleased when I saw this. The other points are acceptable. (The cage overall has some very good features and some bad features.)

How difficult would it be to replace a tiny or non-existing mounting plate? I suspect it would not be that difficult. Any thoughts or opinions??

You should be able to cut the tubes at the mounting plates, and lift the whole cage a bit, slide new, bigger plates under, and reweld. Of course, we'd have to see how it's there right now, but it should be doable. The best answer will probably come from a cage builder once he see the cage

[LateApex]

Check your PM's.

I may be able to help you out.

Jordan

[ADAM]

its not an easy task to replace the plates thats for sure

[P.Po]

Originally Posted by ADAM

its not an easy task to replace the plates thats for sure

Could you expand on that a bit? Would you suggest just welding additional plates around the existing plates instead?

Thanks in advance for any help or advice...

cheers,
Patrick

[ADAM]

well if its good cage you have.. the fit will be tight to the roof...pretty much butting up to it..same with the "a-pillar" down arms

so you have to get a cutting device at the bottom of the tube where it meets your current plates...probably cut off disks wont work cause they are too far offset which would shorten your cage to much.

so... i would go plasma cutter.... so you plasma cut all your cage support points so they are off the current plates....

or mabe some neat band saw?..

then...do you remove the current plates or just weld overtop? if you just weld a new larger plate over the old one there will be a big stepdown to get to the sheet metal...so you have to pound the shit out of it to comply with the floors surface to get a nice flat area to weld the new plate to the sheet metal floors... all this while the cage is hovering above the current plates..(maybe your lucky and the fit is loose ..then its easy).. plus the new plates should be welded on more than one plane...meaning up the sides of the car..making it way harder since you have to bend the plates ..then fit them

you have to do that 6 times... not fun and then reweld all the tubes to the new baseplates...and of course all the tubes ends are now all butchered up from the plasma cutter....so it will be a messy welding area... i would then put lots of gussets to reinforce the baseplate/tube area..just to make sure its good and strong...


its gonna be time consuming.... not to mention you have to pull all your seats and crap out as well...

if you are a good fabricator ..and need to use that type of equipment..you can rent my shop for a few days and do the work yourself if you want...I have all the equipment needed to build cages there....

Adam

[Slowpoke]

Dumb question here... but if this cage was used in PCA racing and has a log book, is there not some equivalency granted? Grandfathering in old cage rules?

Just how many square inches are the mounting plates that you have? 4.5" x 4.5" is all you need. I'm not encouraging trying to get by with inadequate safety equipment... just trying to figure out how far out of spec it is.

[P.Po]

Thanks for the reply Adam!!

The good news is that I would only need to change the mounting points on the main roll bar hoop. So just two mounts need to be updated. Hmmm... based on your description this looks like a tough job. I am going to get somebody else to do it for me, as well as change out some bars and add some door bars (another post on the door bars coming soon!)


Slowpoke, I am not sure about the grandfathering rule applying based on different rulebooks. Regardless, for safety reasons I want to "upgrade" the mounts. The current mounts are just barely bigger then the bar at this point! So maybe 2" x 2"... The area it is mounted on is very strong and not the floor, but I would rather do it right!

cheers,
Patrick

[P.Po]

Originally Posted by ADAM

its gonna be time consuming.... not to mention you have to pull all your seats and crap out as well...

I already have all of that stuff out anyhow since I am making a few changes to the cage. Some part where built very well and other not. Two different shops in Toronto built different parts of the cage...

Originally Posted by ADAM

if you are a good fabricator ..and need to use that type of equipment..you can rent my shop for a few days and do the work yourself if you want...I have all the equipment needed to build cages there....

Would you rent the usage of a tube notcher?? That is about the only other thing we will require to get the cage updated at this point...

Thanks again for your help and advice...

regards,
Patrick

[thgear]

Hey Patrick, may i inquire as to what car this is for?

[P.Po]

Originally Posted by thgear

Hey Patrick, may i inquire as to what car this is for?

Sure, it is for a 944cup/PCA SP2 or CASC GTC(Hopefully) class Porsche 924S!

cheers,
Patrick