MX5 Plus new TALL BOY bar

cooper1896 · Postby **cooper1896** » Wed Feb 29, 2012 10:12 am

Dweezle wrote:I never got time to go see AGI.
Though they are on my list once i get more of this Turbo build sorted.

I want Roll protection that is actually above my head.
I would almost lose the soft-top for that ability.

AGI want to do some measurements with the car to see what can be done.
Hopefully Come up with something new.

I can't recall where I read this (I think it was on this forum) that a possible solution is to run an ordinary Brown Davis, then have an additional bar, that can be mounted ontop of of the top horizontal bar, that would give a height increase equal to the diamater of that additional bar. (I hope that makes some sense).

The question I would have is, how would you mount this additional bar to the BD. If it were a box section I can see how it could be done, but since the BD is tubular, then the design would be more complex. I have a few Ideas that I could possibly draw in powerpoint if someone is interested.

The other question is, whether this would comply with CAMS regulations for Roll over protection...

deviant · Postby **deviant** » Wed Feb 29, 2012 10:43 am

I have seen cars with an extra 'bump' on the main hoop where the drivers head is. These have always been welded on. I see no way that you could have a bolt on one that would satisfy CAMS. Personally I would prefer that more of the main hoop was abover my head than that 'bump' of a few inches width.

All the rules are in here: http://www.camsmanual.com.au/pdf/10_gen ... 2012-1.pdf

Remember, if it does not say you can then you can't...unless you want to pay for testing and certification.

The other option of course is to not have a roll bar at all and enter in standard classes.

cooper1896 · Postby **cooper1896** » Wed Feb 29, 2012 11:04 am

My thought would be to on an upside down u channel profile steel bar (this shape [_] but witht the underscore on the top rather than the bottom)

This would slip over the top bar of the BD, and then be bolted through the BD with High tensile bolts. My thoughts are that it runs the entire length of the top BD bar.

As I said, no idea if this would be CAMS legal, and when I get some time I can read through the regs. It would however mean that I could use my roof, which is a must.

Thanks for the update.
Regards
Andrew.

hks_kansei · Postby **hks_kansei** » Wed Feb 29, 2012 11:16 am

I doubt it would be CAMS legal.
I've not seen a bolt together rollcage/bar that CAMS approve. (granted, they've all been the JDM rollcages with their dodgy tab+bolt method.... it would just act like a great big hinge)

It would also requrie you to drill through the BD bar's hoop, which would likely weaken it as well.

Zcootz · Postby **Zcootz** » Wed Feb 29, 2012 12:20 pm

Bond Roll Cages sell CAMS approved cages

Postby **NitroDann** » Wed Feb 29, 2012 1:11 pm

They are only cams approved if you arent tall.

Dann

Zcootz · Postby **Zcootz** » Wed Feb 29, 2012 1:51 pm

Got distracted with my previous post, I meant to say Bond sell bolt in cages that are Cams approved.

hks_kansei · Postby **hks_kansei** » Wed Feb 29, 2012 1:58 pm

Zcootz wrote:Got distracted with my previous post, I meant to say Bond sell bolt in cages that are Cams approved.

I was referring to bolt together, rather than bolt in.

like this:

deviant · Postby **deviant** » Wed Feb 29, 2012 2:08 pm

It is all in the regs. You can not bolt stuff to the cage without using a fixing method as per those outlined in the book. A U channel bolted to the bar is not going to be something that can be approved and given a certificate.

You can have an FIA / CAMS approved bolt together cage but it needs to be done as per the regs, most that I have seen that are proffesionally built have a rear section that is all a solid piece and the front section is bolted to that.

Anyway this is all a bit academic. If you are NOT going to log book the car or you are NOT entering events that specifically call for an approved cage you can do whatever you want as long as the scrutineers dont consider it to be a danger.

That CUSCO cage is a piece of sh*t.

Zcootz · Postby **Zcootz** » Wed Feb 29, 2012 2:31 pm

As Deviant said, check in the Cams manual. They have examples of acceptable methods of bolting together a cage. They look nothing like the Cusco jobs though... Lol

cooper1896 · Postby **cooper1896** » Wed Feb 29, 2012 5:17 pm

deviant wrote:That CUSCO cage is a piece of sh*t.

But it's anodized! haha

Good discussion guys. Certainly the next step for me is to have a good look through the rule book.
Cheers

deviant · Postby **deviant** » Wed Feb 29, 2012 5:51 pm

Hmmm anodized and with that 7th point I'm thinking you could.....

OurCognitiveSurplus · Postby **OurCognitiveSurplus** » Wed Feb 29, 2012 9:53 pm

People on these forums are very disparaging about these 'bolt together' cages. I appreciate that they might not comply with the CAMS rules, but I would like to see photos of one that has gone over. I suspect it might do marginally better than collapsing like a can of coke like I think some people envisage. (Happy to be proved wrong with a photo.)

For my part, I know that on a stock seat and in a helmet, my helmet hits against the roof if up. I don't think any bar within the roof could get anything like 50mm of clearance. I use an MX5 twin hoop, but because I run in 'road registered' compliance with the CAMS ROPS rules arguably is not required. I think the problem is with the rules in some ways - why have a rule that is simply impossible to comply with in a water-proof MX5?

Postby **NitroDann** » Wed Feb 29, 2012 10:07 pm

Its not impossible to comply, lower your seat.

As for the bolt togethers, I don't think anyone expects them to just crumple, but if it bends at any of those points near your body, the crash wont kill you, the 2 inch steel (or aluminium lol) bar that is located where your torso is supposed to be will.

Dann

deviant · Postby **deviant** » Wed Feb 29, 2012 10:47 pm

OurCognitiveSurplus wrote:People on these forums are very disparaging about these 'bolt together' cages. I appreciate that they might not comply with the CAMS rules, but I would like to see photos of one that has gone over. I suspect it might do marginally better than collapsing like a can of coke like I think some people envisage. (Happy to be proved wrong with a photo.)

For my part, I know that on a stock seat and in a helmet, my helmet hits against the roof if up. I don't think any bar within the roof could get anything like 50mm of clearance. I use an MX5 twin hoop, but because I run in 'road registered' compliance with the CAMS ROPS rules arguably is not required. I think the problem is with the rules in some ways - why have a rule that is simply impossible to comply with in a water-proof MX5?

There are a lot of pictures of crashed or upturned cars with cusco style cages that appear to have survived but in most of those pictures there does not appear to be a great deal of damage to the car so possibly they were more of a soft roll over rather than a big barrel roll with a hard impact on the roof. No pictures of a car being t-boned or anything.

Personally not something that I would be willing to test.