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Location:
Hobart
Registered:
May 2005
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Roll Cage Designs - AE86 / KE70 Specs
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Tue, 23 August 2005 00:16
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Just about to start my cage and was wondering if anyone has some good cage designs, i want to make it legal for the road, so im still waiting to hear from transport about welding it in. I was going to move it back behind the pillar a smidge so that it does affect the seat belts. If any one has some good designs just post them up or PM me.
Iain
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Location:
Adelaide
Registered:
May 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Tue, 23 August 2005 00:23
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Go buy a CAMS manual, there is an entire section in there about cage designs. Its worth the read.
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Location:
Adelaide
Registered:
September 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Tue, 23 August 2005 00:39
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| takai wrote on Tue, 23 August 2005 09:53 |
Go buy a CAMS manual, there is an entire section in there about cage designs. Its worth the read.
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That and get it done by a professional. It doesn't cost that much , and unless you are a very competent welder and fitter, it is bloody hard.
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Location:
Hobart
Registered:
May 2005
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Tue, 23 August 2005 02:12
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My mate is a welder, and all i will be doing is helping. Ill have a look at the CAMS manual then.
iain
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Location:
Adelaide
Registered:
May 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Tue, 23 August 2005 04:54
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Make sure that you 1000% know what you are doing. Screwing up a cage is bad mmmkay.
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Location:
Hobart
Registered:
May 2005
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Tue, 23 August 2005 05:23
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i will make sure that he knows what he is doing as if he roots it up, he has fucked my shell as its a weld in cage. He can buy a new one for me, and then remove all the sound deadnier, that is a shite job.
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I supported Toymods
Banned User
Location:
Brisbane
Registered:
May 2002
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Wed, 24 August 2005 10:54
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I dont think you can build your own cage and have it cams approved. Here in Qld to have a CAMS approved cage it has to be built by someone that is approved by CAMS to do do.
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Location:
Brisbane
Registered:
February 2005
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Wed, 24 August 2005 11:36
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Not completely true, however that is the easiest way to do it.
If you build your own cage, and want the car logged, YOU need to sign the paperwork and accept COMPLETE responcibility for the cage, for the life of the car.
After some of the home made cages I've seen in some of the drifters up here, pay some one to do it.
If it's not right, it's not safe.
How much is YOUR life worth??
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Location:
Adelaide
Registered:
May 2002
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Wed, 24 August 2005 15:07
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A cage can be homoligated providing it follows the exact design, material and execution guidelines in the CAMS handbook pertaining to your chosen motorsport category.
Other designs/materials can be accepted but they must be oficially tested (also according to guidelines).
Road legal, forget a proper full cage. They intrude into the field of vision especially when padded, make it far harder for safety crews to remove your broken body from a wreck and are extremely hazardous to your un-helmeted bonce.
Your only real option will be to re-reg the car as a 2-seater, and have removeble front sections.
Why do you want a roll cage?
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Location:
Hobart
Registered:
May 2005
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Wed, 24 August 2005 16:56
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alright i wanted a full cage to help stiffen the car up as well as provide the protection incase of a crash. The guy doing it for me knows what he is doing and we are going to follow a certain design not a home made job, he is a professional welder for a job and has put cages into other cars before. The material been used is correct size, etc for the transport tasmania down here.
Iain
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Location:
brisbane
Registered:
December 2004
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Fri, 26 August 2005 00:36
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just for a crash... jeeees lol  .... i think its all about wank factor
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Location:
Melbourne - NthSubs
Registered:
January 2004
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Fri, 26 August 2005 03:21
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road or race use?
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I supported Toymods
Location:
Adelaide
Registered:
July 2004
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Fri, 26 August 2005 03:25
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if you just want the cage for chassis rigidity then PM bubbles on this forum, i hear he has an excellent technique for "seam riveting"
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Location:
Hobart
Registered:
May 2005
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Fri, 26 August 2005 03:35
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mainly race but will be used for the road, i will be getting it regoed then installing cage.
Iain
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I supported Toymods
Location:
Ademelaide, SA
Registered:
July 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Fri, 26 August 2005 10:15
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| MR 1JZ wrote on Fri, 26 August 2005 12:55 |
if you just want the cage for chassis rigidity then PM bubbles on this forum, i hear he has an excellent technique for "seam riveting"
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lol
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Banned by his request
Location:
moved to tamworth
Registered:
July 2002
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sat, 27 August 2005 04:59
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there are a couple of diffrent cages,you can have a cage that is just for saftey, then you have a cage that picks up all the suspension towers to try an make a car as close to a spaceframe as possable,it uses the shell aswell to make a cage that transfers load in a way that keeps everything square.cages are easy if you design them for a living.use the cams drawings and go to the track and look at all the front running cars and have a look at there cages and see how they use the cage.triangles are your friend when it comes to strength.
mick
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Location:
Hobart
Registered:
May 2005
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sat, 27 August 2005 12:49
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Thanx for all the replys, im getting car registred first so i have some months to think now, and get design ideas b4 i get it done.
Iain
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Location:
Brisbane, Queensland
Registered:
April 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 04:00
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All right, to be honest I think your attitude and approach is a little off but I'll put that down to the lack of text forums to convey emotion/attitude effectively.
If its going to be street driven then the biggest limiting factor will be your ability to add side impact protection across the doors. Now side impact bars (ideally a high double-cross) not only protect from side impact but also (arguably the reason they're so popular in top-level motorsport) they add a massive amount more rigidity, particularly in beaming.
So, it depends how much you want to push your luck with the door openings, talk to an engineer but for starters I'd recommend you focus on the rear half of the cage.
So you'll have a main hoop, with a harness bar and a double-cross for triangulation. Then you've got a set of rear legs running from the top corners of the main hoop down to the rear strut towers and a bar straight between the strut towers, again with a double cross over. Next you want two bars running straight from the base of the main hoop back to the strut towers, again with a double cross.
Next you need to decide on how you attack the front end of the cage, the first bars to look at are the front legs, extending from the top corners of the cage, running forwards and following the A-pillar quite closely and penetrating through the dash, these should be joined above the windscreen with another tube and you want a double-cross above your head, possible bent upwards to improve clearance. Run another bar joining the front legs just under the top of the dash and depending on packaging, knock up some (smaller?) barwork to link that to the firewall and transmission tunnel.
Don't stop there though or you really are shortchanging yourself in terms of rigidity... more to come later, gotta go finish painting the KE30.
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Location:
Brisbane, Queensland
Registered:
April 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 04:41
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Now you want to run bars running forwards between the base of the main hoop forwards to the front legs. Also its nice to have a bar running across the car between the base of the main hoop, making it into a full circle rather than an upside-down U. This can be dificult to achieve but its quite doable if you use your head, one of the nice ways to achieve it is to run it across the floor to the transmission tunnel and then make up a removable section to bolt in from below and a welded in section to follow the tranmission tunnel from above, thereby linking up the two sides of the cages *and* giving you a tailshaft hoop (depending on how far rearwards you cage is relative to your gearbox).
Talk with your engineer and see what he will allow in terms of barwork across the doorway, if he's too strict, shop around to find a more lenient engineer. In terms of roof integrity its nice to have an additional bar which runs straight from the top of the A pillar to the floor in addition to the bent one following the A-pillar itself. Also where the A-pillar legs meet the main hoop is a weak point so triangulation between the A-pillar and mainhoop in the vertical plane will add significant strength.
Time for another coat of paint on the KE30, is anyone following this yet?
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Location:
Brisbane, Queensland
Registered:
April 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 06:42
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So, badly drawn this shows where we're up to....
From there it depends on what you want to do for side-impact protection and tying the cage into the front suspension. Probably the best compromise you're likely to get an engineer to approve will be a relatively low bar running from about the height of your hips (whilst seated) on the main hoop diagonally forwards down to the base of the front legs. You can just leave this unsupported or tie it into the main hoop at the same point as your A-pillar to main hoop brace and then run another tube straight back from there to the rear struts (and then the option of a double cross on that too).... (another bad .gif image to come later).
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Location:
Adelaide
Registered:
May 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 06:47
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Far out, how heavy do you want this bloody thing to be. Thats the sort of cage which is built for a 300-400hp race car, not for a track day special. Hell, my race car doesnt have that much caging (then again im limited for the cage).
Good ideas, but i woudlnt use a lot of it
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Location:
Brisbane, Queensland
Registered:
April 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 07:50
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Assuming its built in CDS as opposed to chromoly then the addition of a lot of straight triangulation isn't *that* expensive particularly since his friend is doing the actual fabrication.
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Location:
Adelaide
Registered:
May 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 07:54
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No, its not expensive. But that wasnt my point. Its heavy as hell, especially if its done in CDS rather than Chromoly. Its a sprinter, probably with a reasonably stock 4AG... The biggest thing in this equation is power to weight.
also consider that he wants to road register it, which severely limits his cage choices...
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Location:
Brisbane, Queensland
Registered:
April 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 08:06
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Removed a lot of the 'other' bars for clarity but this shows what I'm describing for door bars, with the right engineer you should be able to get this passed and it is 'comparatively' livable for road use. It doesn't look quite right in my drawing because I've got the rear strut mounts too high, and the door bar meets the main hoop a little high but you get the idea.
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Location:
Adelaide
Registered:
May 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 08:25
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You wont be able to get it passed with the head bar in place. They tend not to like those at the RTA.
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Location:
Brisbane, Queensland
Registered:
April 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 08:30
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In which case, make it as straight a line as possible from the rear strut mount to the base of the A-pillar, assuming it is low enough at door height to please your engineer, which it probably will be.
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Location:
brisbane
Registered:
December 2004
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 08:31
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how much does a decently made cage f**king weigh jesus christ lol looks about 500kg
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Location:
Brisbane, Queensland
Registered:
April 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 08:34
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as in..
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Location:
Sydney
Registered:
August 2005
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 10:19
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That cage is a boat anchor....
If you were racing a V8 super car then possibly you may require as much if not more piping. But considering as has been said above we are dealing with a relatively low powered car you are just dragging the chain. Besides this, the driver (no offence intended) probably won't be able to tell between an extreme cage and a basic six point.
To clarify a couple of things too, make sure you do not penetrate any of the cabin. In other words you can not make the roll cage (In club racing) go through the fire wall to the struts nor through the rear wall to the struts. However as this car does not have a rear wall as such, it is possible to tie the rear struts into the cage. They cannot however be used as the structual base of the rear legs. CAMS describe a roll cage as a "safety cage" not a structually integral part of the car. Unless of course you are planning on making a specific tube chassis which then falls under a different section of rules.
A few things to look out for is the foot print of the mounting point. It needs to 12000mm2 as a minimum and a min thickness of 3mm. The mounting footprint can be bent around say a inner sill panel but the top faces minimum width/length must not be thinner than the thickness of the cage.
All bends must have centerline bend radius that is atleast three times it's diameter. Anything tighter and it weakens the structure of the bend. The bends must not be heated to bend. There are special bending machines available that provide the specific bend and radius required. All bends must have a minimal crush and the difference between the nominal dia and the thinnest part of the bend must be 0.9 or greater.
Also wall thickness and diameter have to be considered. All pipes except the main hoop require 38mm dia with a 2.5mm wall or a 40mm dia with a 2mm wall. The main hoop requires a 44.45mm dia pipe with a 2.5mm wall thickness or a 50mm dia with 2mm wall.
Intrusion bars must be level with the top of the drivers hips. and must provide adequate room for entry and exit.
There are soo many other aspects of the cage that have specific guidelines but I won't go through any more as they are pretty straight forward common sence stuff. But things liek visability etc must be abided by.
As for triangulating everything well you are totally correct. Triangles are a cages (and for that manner anything structual building bridges etc) friend, however you have to weigh up the pros and cons of what is being done. The best cages aren't ones with pipes going everywhere, it's the ones that provide adequate strength with minimal weight.
Hope that helps,
Tark
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Location:
Hobart
Registered:
May 2005
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 12:13
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The car its going into is a KE70 with 140-160rwkW depending on boost. Its a AE101 4AGZE with a GT28RS. It should be able to handle a decent cage, but i think the first cage might be a bit too extreme for my use. I really liked the loop near the gear box, might try something like that but a bit scaled down.
thanks
iain
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Location:
Brisbane, Queensland
Registered:
April 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 12:36
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It really isn't a lot of weight and the improvement to vehicle dynamics with a well-built rigid cage really shouldn't be underestimated. Using rough figures from my memory of the last cage I helped build I think that the cage as per the first gif I posted should come out at about 50kg including the mounting plates, so whilst its not light its not unworkably heavy.
The rigidity of a comprehensive cage really does make a marked difference to how a chassis behaves, back when we ran in GTP despite the fact that we would usually have to work reasonably hard to keep our cars down near the minimum weights we still ran a more comprehensive ROPS because the comparisons between our earlier built cars showed that you got better control of the suspension which more than offset any weight or CoG penalty. So even ignoring that I'm talking fairly high level motorsport, take it back to AGP2002's case, he ends up with a car which has greater potential for good handling *AND* is safer, apart from cost I really think its a win-win.
As an aside, one of the cars we ran for a while came with an alloy-cage (allowable as it was log-booked prior to the requirement for steel cages) now we had to run a significantly different spring rate in that car and it still wasn't as nice to drive, in the end the owner modified (note: not permitted under cams rules but thats life) the cage to add much more triangulation to the alloy cage and even that made the car drive much nicer.
But other than disagreeing on how much cage is appropriate I congratulate muvro on an excellent post.
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Location:
Hobart
Registered:
May 2005
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 12:53
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thats HOTGEMINI and others your info is very helpful and look forward to getting a cage at the end of the year when the car is going.
Iain
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Location:
Sydney
Registered:
August 2005
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Sun, 28 August 2005 13:29
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Thanks for the congrats HotGemini,
Yeah I don't disagree that a comprehensive cage gives the vehical better dynamics, both through handling and drivability.
The point I was making was that the difference between a cage with selective design compared to extreme design is minimal. You compare a bolted in alloy cage versus a welded in steel cage. Two very different setups. Any bolted in setup won't do alot for you in terms of body stiffening.
However there are other methodes of body stiffening that are extremely effective and don't add much weight. For instance stitch welding every seam in the car. Reinforcing suspect and known weak points, reinforcing suspension mounts. Most of these would only take a few welds to stiffen and not require extensive pipe work for much the same desired effect. 50kg is still 50kg.
Also if the builder has little if no experience in cage building or vehical dynamics then the cage may not be built to take full advantage of it's place in the car.
In no way am I disagreeing with you in the fact that a cage with X pipes is not more effective. But it doesn't seem that the car is being used professionally nor competitively just a car to have some real fun in. It definately has some mumbo! Being in a KE 70 (Why did I think sprinter...) for cams approval it's not to go into the boot and tie in the rear shock towers. One thing to remember is that without sufficient stiffening of the rear/front suspension having the center of the vehical extremely stiff without any flex can lead to major cracking of structual areas of the body. Namely rails and qtr panels.
One thing to aid in stiffness is to tie the cage into teh body along the pillars. All three 'A','B' and 'C' pillars. TRhis will not only aid in stiffening of the body and for that matter the cage but will also help in keeping the cage rigid during a roll over situation.
With regards to the hoops lower reinforcment, we always install a straight pipe from each side of the hoop. The diagonal meets at the cross bars attatchment point. Adding to the hoops strength.
I have some pics of cages I have done if someone can host them. One in particular is a Group N car and with the installation of the cage from a bolt in to a full weld in the tranformation was totally amazing according to the owner. A well experienced driver.
As said above not disagreeing with you at all but the sort of use this cage is going to see I think minimum is best. Use cost of piping and put it towards good tyres etc. In saying that don't skimp on it either. Pay great attention to reinforcing suspension components as HotGemini said the stiffer the car hte better the responsivness and improvment in handling dynamics. So long as the cars suspension is adaptable.
tark
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Location:
Brisbane, Queensland
Registered:
April 2003
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Location:
Adelaide
Registered:
May 2003
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Re: Roll Cage Designs - AE86 / KE70 Specs
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Mon, 29 August 2005 00:11
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muvro: if you want a place to host the pics then check your PM and email me the pics, ill upload them to my web server.
Good info guys.
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Location:
Adelaide
Registered:
May 2003
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