Roll Cages And Cams Approved?

[Sydneykid]

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.

The need for heat treatement of CM seems to have gone now that most people have the TIG requirements (temperatures) under control.

There are plenty of already engineered CM cages now, so the engineering costs are not as relevant any more. They simply sign off on a pre-existing design, no analysis required.

I have always found prices on cages to be unpredictable, a 4 point from BD for $800 is very cheap. I probably would have gone that way if they had offered me that price when I asked . From memory my quote was $1,200 including M to S freight of course. So $600 was a pretty attractive comparison. Plus it came fully padded, every single piece. Based on what limited padding costs for the race team cars that saved me another $200 or so.

The other reason I went for the 6 point was because of the rigidity question. The front half of the R32GTST is where I could feel the most twist, which is logical since it has over 60% of the weight. Judging by the R32GTR results from fitting the 12 point Bond CM cage, the front half rigidity is the real bonus.

I will be interested in your comments if/when you decide to do the front half of the cage.

Cheers

Gary

[N1GTR]

Ouch, look at the cars in the BG, looks like there were a few dissapointed people at targa

[Duncan]

lol thats actually bana's car in the background I hadn't noticed it there before. Yes that was the car graveyard near the ferry.

Ben, thats actually a good price, as I said mine was pre WSID, everyone in the market is busier these days and prices have gone up.

[evil_weevil]

Thanks everyone for all the great replies!!

Really appreciate it and Im sure alot of other members here have benefited from it.

What Im now thinking is just going that extra mile and going for the CAMS approved rear half cage.

It is more expensive fitting that than a 2nd hand Jap cage, however after doing half my mods and then later on changing them which has made my bank account VERY low, I think I'll just save any future hassles if any arose, and get the CAMS approved one fitted.

I guess I dont wanna take the risk!

Cheers guys,

Chris

[BHDave]

Just a quick question for SK regarding the additional brackets on the hoop to attach to the seat belt mounts.

I have only ever seen it once (added to a cage on yahoo auctions) and i thought it was a pretty bloody good idea to brace the top half of the shell like that, though how much benefit is there really? It's not exactly a common thing (is it?)

Edited January 27, 2008 by BHDave

[Duncan]

most CAMS approved cages have that bar. Pertfect for seatbelt mounting but more importantly helps with chasis rigidity, especially if there is a diagonal bar (ie from B pillar one side to C pillar other side) there as well

[BHDave]

I'm taking about actually attaching the cage to the stock seat belt mounts up on the b pillars. I thought that was what sk was getting at....

[t01-100]

duncan - its based on standard cams design and constructed out of steel by jason white. little unusual yeah, but not many options when it comes to rx7 with the rear space being so small and tight. my old gtr went to the arches, but gtst was similar to this on the towers, but this alone made it ineligible for ipra events being out of the cabin space.

roy - yeah have read a report similar to that effect, honestly didn't even consider specifying which way, but doubt i'll be pushing as hard as him so not too stressed! i wanted to run an a-pillar sainz bar too, but found that bar and a seat with head support wings wouldn't both work so the seat won. the cage and interior will be silver to match the exterior. currently got the dash off being trimmed in alcantera. doors trims will be flat carbon panel and only minimal plastics being reinstalled too keep a clean look.

[Roy]

I'm taking about actually attaching the cage to the stock seat belt mounts up on the b pillars. I thought that was what sk was getting at....

You have to be sure that the cage is positioned in a way that the bracket does not interfere with the operation of the seat belt. On a race car its easy, no seat belts, only harnesses. On a road car where you need to keep functioning seat belts then it becomes a little bit more involved....

[djr81]

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.

Just a small point.

Whilst chrome moly may be stronger than a cold drawn steel it is not stiffer, least of all if you are using a thinner walled tube.

Remember that stiffness is a different property than strength. Easiest way of thinking of it is that stiffness is a property of the materials shape whereas strength is a property of the material itself.

Also aluminium has a Youngs modulus (the measure of stiffness) of only 1/3 that of steel. So your aluminium strut brace may be light, but it is also probably useless.....

[Sydneykid]

Also aluminium has a Youngs modulus (the measure of stiffness) of only 1/3 that of steel. So your aluminium strut brace may be light, but it is also probably useless.....

If you are bending your strut brace, then its design is wrong anyway. It should only need to be strong in compression and alloy is plenty good enough for that.

Cheers

Gary

[djr81]

If you are bending your strut brace, then its design is wrong anyway. It should only need to be strong in compression and alloy is plenty good enough for that.

Cheers

Gary

My point was simply this. For the same sized/wall thickness etc tube an aluminium alloy will compress/lengthen 3 times as much as an equivalent steel section for the same amount of load. It may well be the same strength, just nowhere near the same stiffness.

An old maxim: Use steel for stiffness. This is particularly true at high temps. Of course proper carbon fibre is good too.

Edited January 29, 2008 by djr81

[just_racing]

This isn't any help for you guys in Sydney but this company does a very cage and start with a 6 point CAMS approved for $1850 I think.

I'll get my car back with the cage fitted next week and will put some pictures up.

http://motorsportsolutionsaustralia.com/

[BBGTR]

Just picked up my car from Meridian Motorsport today:

They did a great job to CAMS specs, recommend them.

Regards

Andrew

[Roy]

Similar to Snowies only MIG welded, not TIG.

Meridian make nice cages, in the second picture it looks like the back stay has a weld in it where the fiagonal joins? Is that the case?

BBGTR, all your car needs now is a set of these and it will be just about my dream R32

[BBGTR]

Similar to Snowies only MIG welded, not TIG.

Meridian make nice cages, in the second picture it looks like the back stay has a weld in it where the fiagonal joins? Is that the case?

BBGTR, all your car needs now is a set of these and it will be just about my dream R32

If you are talking about the top of the daigonal where it meets the stay and the main hoop:

Not ENKEI's, but I'm expecting delivery of some titanium silver versions of these within two weeks, hopefully in time for the 16/17 PIARC meeting:

Cheers

Andrew

[Roy]

Ooooh. Still very nice. If i ever get a GTR the Enkeis will be going straight on

[DRIFTER]

bbgtr, can we have some more photo's of how the side intrusion bars are mounted?

[BBGTR]

bbgtr, can we have some more photo's of how the side intrusion bars are mounted?

I'll take some tonight when I get home.

Regards

Andrew

[BBGTR]

Intrusion bar to B Pillar Hoop

Intrusion bar to sill