Roll Cages And Cams Approved?

[evil_weevil]

Hey guys,

I know theres quite a few aussie workshop etc (eg bond roll bars etc) which make and fit CAMS approved roll cages.

Just want to know, say with Cusco, nismo and other brand roll cages etc, can they be cams approved?

If they arent and you did a supersprint/hill climb etc, how would they tell the difference? If they could? no go - cannot enter that event?

I guess if you had a log booked car you could tell (as it would need to be approved anyway!), but for your streeters with cages, like snowy's, Roy's, and many other members here, whats the go?

Cheers,

Chris

(Sorry for teh n00b questions!!)

[Roy]

Have a look in the Vic section. There are some decent posts in there on this subject.

Here are some replies to similar questions...sorry some may not make complete sense without the relevant posted question but you will get the idea...

A guy wanted to mod his Cusco cage to get it compiant...

Have you actually spoken to a cage manufacturer about what you have planned? I suggest you do so. It may be better to sell your cage now.

Things to check is the diameter of the main hoop. Its probably smaller then what CAMS/FIA require. Most Jap cages uses thicker gauge steel to make up for the smaller diameter, so whilst beign an equivelant, its not recognised as beign equivelant unless you have the whole cage engineered. Here is the funny thing, no cage builder (never say never, but its a good rule) will re-work someone elses cage as they become the custodian of the burden/risk/insurance of the cage.

Also what you suggest with the front A pillar supports will not work as well as just not using the front legs and getting them made locally by a cage builder. The front legs have too many bends/points of failure. It basically has to go through the dash, going around the dash, in front, causes too many rigidity problems. It is very difficult for a leg with so many bends to pass the loading tests the FIA dictate (its in the CAMS manual) . I would have to check this years regulations but if it has too many bends then it has too many bends, no amount of gussets or bars will help it pass the loading test which is a factor of the cars weights applied from different directions to the top of the A pillar / roof line. The fact that when you comply striclty to the FIA/CAMS guidelines you dont have to prove the strength of the cage as it is implied to be strong enough if compying with the guidelines....thats a big bonus to many cage fabricators.

The cost of FEA analysis on your custom front legs??????? As an ex scrutineer im just passing on some of my experience...of course this is all for nothing unless you actually want to get the car log booked with CAMS or CAMS start applyign the wording of their handbook to Level 2 Speed and Non-Speed Events.

But best of luck, will be interesting to see how you go with it all

Also a question about HKS chrome moly cages...

In a perfect world i would go chrome moly. But its important to firstly consider what the rules and regulations say. Should you want to adhere to them...then.

The main roll hoop and cage tube must be a certain diameter and wall thickness. This assumes mild steel and is what stipulated by CAMS/FIA. Now as you point out the point of chrome moly is that its stronger so you can go to a thinner wall thickness and hence lighter cage. BUT, there is the problem. You are no longer using the wall thickness as dictated by the regulations.

So this means you now need to prove that its an equivelant. So this means you need to engineer the cage. Now engineering a cage is very different to say engineering a car. Engineering a car is basically wives tales and empirical experience. Engineering a cage is a pure engineering exercise, and includes 3D modelling and Finite Element Analysis. (FEA). So the exact same cage in chrome moly will automatically cost thousands more as a result of the egineering exercise associated with it as now the cage mnaufacturer has to verify that its equal or exceeds the FIA guidelines. As they are assuming all the liability for the cages safety, the engineering exercise is often quite exhaustive and needs to pass the load tests i mentioned above.

So you have two basic choices...strictly use the FIA/CAMS guidelines to build your cage. Or the minute you change a single aspect of it, like material wall thickness with chrome moly then you have gone free design and the cage needs to be engineered.

So unless you have a serious competition car and going gung-ho with your cage then the engineering of the chrome moly cage can easily double the cost. So thats one aspect of it, but there is also the fact that chrome moly needs to be heat treated after its welded. So you would want to be sure its beign fabricated with approved weld procedures which have undergone tensile tests etc and radiography to ensure that the post weld heat treatment achieves the desired grain structure.

So, if someone is payign for my cage...go chrome moly. If i have cash to burn, go chrome moly. If you want a jap cage that will not comply with CAMS guidelines then go with a HKS Kansai cages etc. Otherwise, its easier to go mild steel

Some other posts about random questions...

I think its a little too general to say bolt in, weld in. Often cages are a combination of both. You can weld in a 4 point cage and in my eyes it will be next to no different to a bolt in 4 point cage. Both are secured at the base of the B-pillar, rear inner guards, with a few diagonals etc. Maybe a harness bar, which is a big thing as it gives you a sensible and safe place to intall your harness. A botl in cage can still be fastened using the seatbelt restraint to the B-pillar. Ok its not as great as abig gusste all the way up the B-pillar...but there isnt that much difference.

Now from there i think there are way too many differences to make too many generalisations. But all the people running out and buyign Japanese cages, do so at your own risk. There is a clause in the CAMS book which means you are at risk of not being able to run your car.

9. NON-COMPLYING SAFETY CAGES

Safety cage structures which do not comply with these regulations or are not otherwise specifically approved by CAMS or the FIA are prohibited in all levels of competition. However, in cases where the type and/or status of the event does not require a vehicle to be fitted with any form of safety cage, approval of structures which do not comply with these regulations may be granted for the event by the Stewards of the Meeting

If the event is run under CAMS insurance, the day will come when the Stewards and their scrutineers realise they are assuming responsibility for any injuries sustained from a non-compliant cage...then its wont be long after until you are told to remove them. I dont srutineer anymore because there are too many things like this which ppl complain about...and as an scrutineer i did not want to be advising the Snr Stewards that the car cant run.

And finally...

hat do you mean by engineer? I think its important when talking about roll cages to use the proper terms otherwise we all end up confused

Now, as mentioned previously, technically speaking if you have a cage and doing any form of motorsport then it should comply with Schedule J of the CAMS handbook. Which is based on FIA guidelines. For the time being though in events where you dont have to run a cage, like L2S Sprint days and Drift days, they are letting you run any cage provided the scrutineer is happy. Who knows how long this ruling/judgement will stand.

But getting back to your question. Bolt in doesnt really mean anything specific. You can have abolt in cage that is in strict accordance with Schedule J and it is perfectly legal and doesnt need to be engineered to use on the track. (Will talk about street in a minute, for the minute we are only looking at track) or you can have a Jap bolt in cage and technically speakign you shoudl not be allowed to run it a track day as it does not comply strictly with the Schedule J guidelines. So being bolt in doesnt really matter, it doesnt make it or stop it from beign able to be used on the track.

Now the term engineering needs to be also clarifiied for the sake of the discussion. Engineering to ensure the cage is legal for street use is completely different to when you say the cage is engineered for track use. Two vastly different things. To get a cage (bolt in or welded, doesnt matter) engineered to make it legal on the street isnt too difficult. Stay in line with Schedule J, dont impinge on occupancy space, register the vehicle as a two seater and work with your states registration body and you should be ok. Its all very subjective, but the engineers responsible for engineering cars for registration again will help you get it legal. General rule of thumb, stick with a 4 point cage and in lin ewith Schedule J and its a lot easier. The more complicated you make the cage and as soon as you go past the B-pillar it gets so much harder ot engineer for the street to keep legal.

So this bring sme to what is meant by engineering for the track. Its a far more complex task and is genuine engineering. not like for registration where its general rules of thumb. To engineer a cage for track work requires calcualtions and modelling on computers to satsify the requirement for rollover protection etc.

So when do you need to get your cage engineered for the track? You have two choices. Make the cage in strict accordance with Schedule J and you will be fine. No need to get it engineered. Schedule J exists to guarantee an accepted means of going about roll over protection. Its a known and recognised shopping list you can use to compile your cage that will ultimately ensure the design is safe. If you stray even in the slightest from Schedule J then you need to have the cage engineered.

So if you want to use a different diameter and wall thickness material you need to have the cage engineered. Thats why chrome moly cages are so expensive. You can use chrome moly as it has a higher tensile strength meaning you can use thinner, hence lighter tube. But because you are no longer using the prescribed diameter your cage is now free design and needs to be engineered. So it needs to be shown that the cage offers equivelant or superior performance then what is described in Schedule J. If you want to use a slightly different backstays etc etc. same thing. Any deviation form Schedule J and it requires engineering. So this can apply to a 4 point bolt in cage, 6 point bolt in cage or and welded in cage.

So now of you have your engineered for the track cage out of chrome moly, and its still your road car, then now you have to go to the registration body and the associated engineers who are consulted for road worthy matters. If its purely a track car then thats not an issue, but if its a road car then .... you need both types of engineering.

So that all said and hopefully understood, lets look at Jap cages. The daimeter of the main hoop is generally different to what is outlines in Schedule J. So to be legal for track use it needs to be engineered by a cage manufacturer. A 4 point bolt in Jap cage may pass if the engineer can demonstrate that the grade of steel and wall thickness used allows for a samller diameter main hoop to be used. As soon as the Jap cage is a 6 point cage, its pretty safe to say it cannot be engineered as it cannot pass the load tets they model on the A-pillar. It has too many bends in the front leg, they have too many bends to simplify installation by not having to remove the dash, Instead the front leg bends around to follow the dash's lines. The extra bends mean it will fail every time. So waste of time trying to get it engineered.

Hope that helps explain a few things

Anyway, thats technically what the book says. For the time being you are ok

[Duncan]

hey nice summary Roy.

Who was the scruitineer posting? Sounds like they know their stuff (not always the case....)

[evil_weevil]

Roy!

Very great read up mate, really appreciate it!

The reason I ask is, I can get my hands on a cusco cage - I just want to be safe - i.e. safe on the track inthe worst cast scenario, and of course being able to enter events. Otherwise spend a bit more and get bond rolls bars to do up one and knowing that its CAMS and FIA approved, by the sounds of it, to schedule J

Will certainly look into it more,

Thanks again Roy,

cheers,

Chris

[Stupid Toyota]

Not all Japanese rollcages go around the dash. There are plenty available which penetrate the dash as required. Cusco make them, and they are available in steel (Safety21 branded) or chromoly (Cusco branded).

Of course that doesnt guarantee compliance.

They use 40mm tubes with 2.0mm wall thickness in Safety21 cages, and 40mm tube with I think 1.6mm wall thickness for the chromoly.

Here's a link to a pdf from the Cusco Japan website. I can't read Japanese but it seems to have load ratings and references to FIA etc. Maybe helpful, maybe not...

http://www.cusco.co.jp/products/pdf/roll_b.pdf

[t01-100]

the best thing about a custom cage is you can space it right out to the edges of the cabin to maximise passenger space... if you didn't have the side intrusion bars, a cage like mine wouldn't be very painful to live with on a daily basis.

[Roy]

hey nice summary Roy.

Who was the scruitineer posting? Sounds like they know their stuff (not always the case....)

LOL...the scrutineer was me. I dont do it anymore as i didnt find it near as much fun as i thought i would

All the blurb extracts are from my posts....so if any of it is wrong let me know so that i can stop posting wrong info...i havent really paid all that much attention to any changes that may have sprung the last 18-24 months

[Duncan]

rofl, very deceiving then racing is always more fun than helping run the day, I've got no idea why those guys do it, and I am very thankful they do!

Stuart, love the cage in the rx7, unusual design with the rear strut towers instead of wheel arches (and it would work just as well in a 32 I think). Did you get the cage engineers or is it based on one of the cams designs?

[Roy]

the best thing about a custom cage is you can space it right out to the edges of the cabin to maximise passenger space... if you didn't have the side intrusion bars, a cage like mine wouldn't be very painful to live with on a daily basis.

RX7! Looks the goods, only i thought there was a trend away from that arrangement for side intrusion after that design was found to have contributed to Simon Evans injury in a crash a few years ago.

But instead the trend is to bend an almost u shape in two bars and tie them together with some gussets. like...

Either way, looks great and keen to see the finished car. What colour will it be?

[Duncan]

love to know how they are going to put that in a car now without cutting the roof off, and it looks damn hard to get in and out with that a pillar brace.

[benm]

They build the car around the rollcage.....

[Merli]

So how much weight difference are we talking about between a steel and chromoly cage?

[Duncan]

cromolly is about 30% stronger, so in theory it is about 30% lighter by going smaller or thinner for the same strength. Basic cage is about 50kg. But of course you can't get exact match in cromolly sizes, so unless it is engineered you probably end up with a cage that weighs the same as a steel cage but stronger.

[Sydneykid]

Some additional bits;

The chrome molly cage in a V8Supercar is 20kgs lighter and 20% stronger than an equivalent steel tube (say CDS 350).

Welding chrome molly is pretty well documented now, and testing after welding is not generally required any more.

Keeping in mind that CM has to be TIG welded, CDS is OK with MIG welding.

The material required for a CDS 350 6 point cage with side intrusion costs around $1,000, CM is betwen 2 and 3 times that.

Using a professional engineer for an FIA standard roll cage analysis costs around $1,700 for the more complex designs.

Using a standard CAMS/FIA design avoids the requirement for analysis.

A decent CAMS FIA standard CDS 6 point roll cage with side intrusion bars and the necessary padding would cost around $4,500 to have made in a recognised workshop. Add $1,500 to $2,000 for a CM equivalent.

Check that Jap cage out well before you buy it and compare its specs to the CAMS/FIA ones. Many have pieces that comply even though the whole cage might not.

What did I do?

I simply couldn't justify spending that sort of money for the types of events I do. So I bought a used Jap made 6 point (no side intrusion) cage for $600 that came unwanted in an imported car. I immedialtely set about improving the footings to CAMS/FIA standard as they were considerably undersized. I also added some B pillar tags to the seat belt mounts. That cost about $50 for materials and around 3 hours of MIG welding. I also made, at the same, time some underfloor strengtheners the same shape, as the cage didn't come with them. I upspeced the fasteners to M10 high tensile allen bolts, as what came with the cage were uncoded, that cost $80. That's about it for now, so far I haven't had any issues with scrutineering at club level events. So for a bit over $700 and half a days work I have a car that I feel much safer in. As a bonus it now responds better to set up changes, so there is obviously some chassis rigidity increase.

The plans

Other than the main hoop and the (bent) front legs, all of the the other bars in the cage are CAMS/FIA spec. So if I ever want to go an open race meeting I will have to replace the main hoop at the very least. That's not such a big exercise as there are several guys that will bend one up to duplicate the current shape, cost would be around $200 in CDS 350. MIG weld on the necessary mounts for the existing rear sections and it's a CAMS/FIA legal 4 point.

The front is were the hard work is involved, I would have to measure and draw up what I want as the existing (bent) design can't be used. At the same time I would do side intrusion and (legal for Improved Production) extensions through the firewall to the strut towers. Taking the dash and windscreen out to fit and weld in the front sections is the time consuming bit. I haven't added up the bits precisely but I suspect around $1,000 all up would easily cover it. In the end I would have a legal CAMS/FIA 10 point cage with side intrusion that cost around half what getting one made would cost, plus 2 to 3 days of my time. The big advantage is that I have spread the cost out and I didn't have to find $4.5K all at once.

Cheers

Gary

[Roy]

What did I do?

I simply couldn't justify spending that sort of money for the types of events I do. So I bought a used Jap made 6 point (no side intrusion) cage for $600 that came unwanted in an imported car. I immedialtely set about improving the footings to CAMS/FIA standard as they were considerably undersized. I also added some B pillar tags to the seat belt mounts. That cost about $50 for materials and around 3 hours of MIG welding. I also made, at the same, time some underfloor strengtheners the same shape, as the cage didn't come with them. I upspeced the fasteners to M10 high tensile allen bolts, as what came with the cage were uncoded, that cost $80. That's about it for now, so far I haven't had any issues with scrutineering at club level events. So for a bit over $700 and half a days work I have a car that I feel much safer in. As a bonus it now responds better to set up changes, so there is obviously some chassis rigidity increase.

The plans

Other than the main hoop and the (bent) front legs, all of the the other bars in the cage are CAMS/FIA spec. So if I ever want to go an open race meeting I will have to replace the main hoop at the very least. That's not such a big exercise as there are several guys that will bend one up to duplicate the current shape, cost would be around $200 in CDS 350. MIG weld on the necessary mounts for the existing rear sections and it's a CAMS/FIA legal 4 point.

The front is were the hard work is involved, I would have to measure and draw up what I want as the existing (bent) design can't be used. At the same time I would do side intrusion and (legal for Improved Production) extensions through the firewall to the strut towers. Taking the dash and windscreen out to fit and weld in the front sections is the time consuming bit. I haven't added up the bits precisely but I suspect around $1,000 all up would easily cover it. In the end I would have a legal CAMS/FIA 10 point cage with side intrusion that cost around half what getting one made would cost, plus 2 to 3 days of my time. The big advantage is that I have spread the cost out and I didn't have to find $4.5K all at once.

Cheers

Gary

Fair point... But what you have done using the Jap cage? Why not just go to Brown-Davis or the like and get a CAMS/Roadworthy 4 point cage out of CDS for less then $800 fitted and painted with all the CAMS paperwork? I dont see the point of stuffing around with Jap cages, especially considering the money ppl are asking for them used. (whats the history of the cage, out of awritten off car? Is it damaged?)

If i ever want to put front legs etc, or side intrusions etc then it can easily be accomodated and paperwork amended.

Sometimes there is an easy way, a hard way...and of course the interesting/different way which is what you have done With cages i think we should just do things the easy way...cannot rate Brown-Davisd highly enough

Also based on the cage builders i spoke to before buying my cage from Brown Davis, going chrome moly will cost more then an additional $1500-2000 (assuming full 6 point cage like you described). The cost of materials, additional labour, (heat treatment), TIG rather then MIG etc plus engineering means a much higher cost. Well thats what was explained to me by several constructors that i spoke to...and makes sense. LOL, but im not surprised that you (SK) can get things cheaper then the rest of us

Will post up some pics of the cage tonight...its nothing exoticl, just your basic 4 point cage with harness bar. I will be getting some side intrusion bars done when i get my new MOMO seats ANy good cage builder will be able to build you a simple but well made cage like i wanted...or a work of art that costs the earth.

[Roy]

I tried to grab a good digi cam from work, but they are all out on jobs so had to use my old thingie. So here are some pics of the cage i had made. Nice simple street/track half cage.

Depending on what colour seats replace my current one i plan on painting the cage (either something to contract the silver body or match it to the body if the seats end up being blue or red) and then carpet the back so i can leave the seats out and the interior still look tidy

[Stupid Toyota]

I dont think I have any pictures of my cage here, but was done by Nambour Radiators north of Brisbane.

CAMS compliant with papers and cost $1800

Wasn't painted or anything, just welded in but for the price, who'd argue?

Turn-around was a little slower then quoted but over-all Im happy. (Mind you, I haven't "used" it yet lol)

It's a full cage, tagged to A pillar. Simple single rail side intrusion, roof bar and harness bar etc.

[Duncan]

Mine is very similar ST, and I also paid 1800 for it. Painting it was a bitch.

Mark's from bond roll bars was pretty much the same and about 1500 (in the old days, ie before WSID opened).

It was tested extensively at targa tas this year. 6 times in fact

[benm]

I've been told by a couple of people that have/seen the Bonds Rollbars don't hug nicely, any comments on that? My workshop quoted $2000-2500 in steel for 6 point which compared to posted prices is quite expensive it seems.

[Stupid Toyota]

Mine is very similar ST, and I also paid 1800 for it. Painting it was a bitch.

Mark's from bond roll bars was pretty much the same and about 1500 (in the old days, ie before WSID opened).

It was tested extensively at targa tas this year. 6 times in fact

Ouch, well hopefully I won't need to test mine in the field like that, but it's always good to know it's there. I don't know if I'd really like to go chromoly due to the possibility of failure if it's not right. I know it can be a good way to save weight, and if you don't crash it'll never be an issue but hey, I only have one life to throw away...