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Roll cages?


WhangareiKE70

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Hi guys,

When I bought my latest KE70 (2 door wagon), it had a full roll cage started in it, with basically the side intrusion bars left out, as well as the bars from the dash bar to the front turrets, and it has not yet been gusseted. I have just been thinking about what I really want to use this car for, and am thinking that a full cage may not be necessary, and a half cage might be more suitable.

What are the legalities surrounding certification of a full/half cage? Do I need to do the two track days a year (or something like this I hear) with a half cage to keep it legal as with a full cage?

Basically the end use of the car will be a cool street car, which can also be used for track days and the like. I don't honestly see myself being the next D1 champ and if I am looking to go that way I would probably build a dedicated car.

Let me know your knowledge on this subject.

Chur, Hayden. :D

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is existing cage homologated?

No, which is the other thing that worries me. I don't know who welded it up so I can't say if they are a certified welder or not, if that's important (which I would think it probably is). I know the tube used to build it is up to scratch, just not sure on the construction.

The guy that had it before me had a 400+hp evo engine it and got scared of it so pulled it off the road to put a cage in it and never finished the job.

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good point...a mate bought a car with a "full cage" in it.wasnt homologated,turned out to be made of exhaust pipe...

see if you can see any drill/inspection holes in it anywhere,may tell you the thickness etc

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Half cage things cant enter the front passenger compartment

if it does then your looking at a fail/make sure the seating position is forward enuff so your head cant hit etc

then you "might" get away with out a MSNZ authority car / cert

not sure about onroad/WOF issues with half cages

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Don't forget the main hoop min dia. changed at x-mass... you will need to measure it to make sure it still complies.

the main reason for the homologation question.

personally wouldn't waste my time with a non-homologated cage, unless i knew the fabricator. too many pitfalls, and i used to be MSNZ Scrutineer.

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Don't forget the main hoop min dia. changed at x-mass... you will need to measure it to make sure it still complies.

the main reason for the homologation question.

personally wouldn't waste my time with a non-homologated cage, unless i knew the fabricator. too many pitfalls, and i used to be MSNZ Scrutineer.

I was aware of the main hoop min. diameter change and in the Trademe auction when I bought it, it did mention it being up to spec with the new laws.

I can't measure it right now as it is at my parents place.

However from the gist of things I will probably be better off going half cage.

smokin' joe, seeing as you used to be a MSNZ scrutineer, do you know the legalities in terms of half cages in motorsport/on road use?

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I'm also registered with MSNZ as a Clubsport Scrutineer

Half cage things cant enter the front passenger compartment

if it does then your looking at a fail/make sure the seating position is forward enuff so your head cant hit etc

then you "might" get away with out a MSNZ authority car / cert

not sure about onroad/WOF issues with half cages

Page 297-312 of my Manual (I opened it just for you) are about cages : there are a lot of word, the above is my interpretation

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Give my brother Neil Marshall a bell on 0274466255, he's been building homologated cages for club, rally and drift cars for years.

I could give you some of the jizz but I'm not as up to date as him and things changed a heap at Christmas.

Material certs and photographic evidence of the welds and bends is part of it.

Log books, Car club membership and sanctioned meetings are also a requirement for a cert.

MSNZ scrutineers don't need to know the specs for homologation they only need to know it's homoligated, not the same thing and from memory the homoligation standard and design of the cage can change depending on the classes you want to run in as there is different racing bodies for drags, traction, drift, rally, club.

WAY more to it than some black pipes stuck in a car.

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did a quick google : reckon its been answered here

http://www.lvvta.org.nz/knowledge_base.html

Q: I have a bolt-in roll cage that came with my WRX. It was removed prior to being complied, but now I'm thinking about putting it back in. I know full cages are illegal, so I've unbolted the front-section, tidied it all up so there's no sharp edges and re-padded it. Now I basically have the main hoop, two bars that go back towards the rear wheel arches and a diagonal bar that goes between them. My only concern now after putting it back it, ready to be certified is where the main hoop bars that run down the side from the roof to the floor sit. The way the cage has been built, these aren't positioned behind the front seats, but more so alongside the upright. Same with the part that goes across the roof, this is basically in-line with the front seat's headrests. It's all padded up, but is this going to be okay for a LVVTA cert? I've read the information on interior impact zones, but I'm still not quite sure?

A: You're right about removing the parts of the cage forward of the main hoop, so that now you're effectively left with a 'roll-bar' as opposed to a 'roll-cage'. There are two things I'm not sure about from your letter; firstly whether or not you want to have rear seat passengers, and secondly whether or not you want to compete in motor-sport events.

I'll assume you're not interested in the competition side of things; if you are, contact MotorSport NZ and they'll provide you with the information you need on what competition roll-cages have to comply with.

If you don't want rear seats, that eliminates another problem; all you need to do is have it LVV certified (as a 2-seater) to make sure everything is positioned far enough away from occupants and appropriately padded. You'll need to 'plug' the rear seat and seatbelt anchorage holes so that it can't become an unsafe 4-seater 10 minutes after the LVV plate goes on.

If you do want rear seats, all parts of the roll-bar will have to be outside the 'A-zone'. This is an area that swings forward in an arc from the 'h-point' (sit in the normal seated position and put your finger on your hip-bone) out 900 mm, or 700 mm if you have web-clamp retractor seatbelts, covering an area (width-wise) of 320 mm. Check out the diagram out of the LVVTA Interior Impact Low Volume Vehicle Standard which shows the A-zone, and although the drawing is of a pair of front seats, the same applies to the rear seats.

This is like a safety area you need around you in the event of a frontal collision, to protect your head and chest from solid or sharp objects as your body is catapulted forward and downward during a collision. Even with seatbelts, because of seatbelt 'spooling' out of the seatbelt retractor reel, seatbelt fabric stretch, and body contortion, a human body moves an truly unbelievable amount in a crash.

In nearly all cases, rearward bars intrude into the rear seat A-zone unless they are tucked up tight along the cant rail (the roof section that runs along the top of the side windows) and runs down tight beside the rear pillar. If that doesn't knock your roll-bar out, the diagonal certainly will. One point to remember with roll-bars is that if you run the rearward bars tight along the roof-line and then tight down the pillar (so as to comply with road-going legal requirements), it almost certainly won't meet Motorsport NZ's requirements for racing because a huge amount of the structure's strength is lost by the inclusion of a bend. Take a look at roll-bars and roll-cages next time you're at the race-track, and you'll see that all the bars from the main hoop back toward the rear of the car are all straight.

So, to your point about the position of the main hoop - simply put, it can't be positioned within the A-zone, and from how you've described it, I suspect that it would be. The A-zone has to be measured with the seat back in its normal driving position, and the seat base in its mid-point position if it is (fore-aft) adjustable. Could you shift the main hoop back to behind the front seats and out of the way of the A-zone?

and if you want some more reading : http://www.eurosport.org.nz/forum/viewt ... f=1&t=8201

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That seems to answer my question. My roll cage would consist of a main hoop and two bars that go down towards the rear of the car, and diagonal braces between these and also in the main hoop. The main hoop should sit well behind the front seats position so it should be all good. From the sounds of it I will just need to plug the rear seatbelt anchorage points and bolt holes for the rear seat.

Should be the goods.

:D

Cheers everyone. :thumbright:

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You still need homologation for a half cage, but you don't need an authority card if it's behind the drivers compartment.

The welder doesn't need to be trade certified, but your welds need to look good in the photos and will be checked during scrutineering of the first event you enter. You can leave the front bars and not add side intrusion too - but this will require an MSNZ authority card to be legal for the street.

If you want solid information as opposed to convoluted opinions, send me a PM.

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You still need homologation for a half cage, but you don't need an authority card if it's behind the drivers compartment.

The welder doesn't need to be trade certified, but your welds need to look good in the photos and will be checked during scrutineering of the first event you enter. You can leave the front bars and not add side intrusion too - but this will require an MSNZ authority card to be legal for the street.

If you want solid information as opposed to convoluted opinions, send me a PM.

does the ruling still apply that if the cage extends foward of the B pillar fixed seats and harnesses must be used??

i merely pointed out, that as a former scrutineer, i wouldn't touch a non-homologated cage unless i knew the fabricator............ too many pitfalls

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Sorry to hijack your thread but I was wondering someone I know is building up a couple of cars he has put full cages in both of them, one cage is part of a a tube chassis and is just some random design and the other is welded to the original chassis

I told him you will probable never be aloud to put those cars on the road or even a track, they don't have much in the way of side intrusion bars, he thinks because the rego is on hold he can just go and get a wof when they are finished.

Can you have a full cage in a road car?

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