Questions about roll cages

[cat007]

Hey all

I'm wanting to get a half for my supra so I can feel a little safer when raging around the track.
I don't want a full cage, because, well I just don't think it's necessary and is a bit overkill and I want to be able to use the car on the road as much as I can between events.

What are the MSNZ rules for a half cage? I've looked on their site but cant find what I'm asking.

What type of events would I need to do as a minimum to have a half cage, and how many per year?
How often will I need to get the cage re-inspected?
What are the requirements for a MSNZ spec cage? Does it need to be chromoly and what wall thickness etc etc?
Does a half cage allow you to keep dashboard and interior (except for rear seats)?
Does anyone have a half cage and have a lot of pics that I can look at and see what I'd need to remove?
Are there any limitations from getting a MSNZ spec cage? I know the NZDRA rules are different - so if I turn up for a drag event with a MSNZ spec cage, will I still be allowed to compete etc?

Cheers everyone

Hunt

[DRFTIN]

any cage used for motorsport must be built to specs and homologated
homologate once (before painting) and its good until you break it
specs: dunno but they're in the schedule A in the msnz website somewhere
i believe you can cert a half and not need authority card (could be wrong) but if you get authority card you have to have the logbook signed off twice a year
why would a half cage mean you have to lose the dash? build design it right and you can keep all interior
MSNZ and NZDRA are not compatible not sure on the specifics

half cages are crap and most track drivers will agree, only useful for rollover (yeah i've rolled twice but generally you dont)
get a full cage with well designed side intrusion (or even no side intrusion if you want) and have the front legs tucked well into the pillar and dash then it will be hardly noticable for the road

[cat007]

any cage used for motorsport must be built to specs and homologated
homologate once (before painting) and its good until you break it
specs: dunno but they're in the schedule A in the msnz website somewhere
i believe you can cert a half and not need authority card (could be wrong) but if you get authority card you have to have the logbook signed off twice a year
why would a half cage mean you have to lose the dash? build design it right and you can keep all interior
MSNZ and NZDRA are not compatible not sure on the specifics

half cages are crap and most track drivers will agree, only useful for rollover (yeah i've rolled twice but generally you dont)
get a full cage with well designed side intrusion (or even no side intrusion if you want) and have the front legs tucked well into the pillar and dash then it will be hardly noticable for the road

I just thought a full cage would be a bit overkill, as I want to use the car on the street still. The only thing I don't want is people seeing me driving it on the street and laughing because they think it's just for show haha

Price for a half cage is around $7-800ish from what I've read. I'm guessing a full would end up being about twice that - But you can't put a price on safety, really.

[cat007]

What are the penalties if you don't have the log book signed off twice a year?

[Distrb]

What are the penalties if you don't have the log book signed off twice a year?

cant renew authority card, which leads to not being able to get wof. signing of your logbook only happens when you are audited for an event running under a MSNZ permit.

if you get a half cage fitted, and choose to get it certified to be legal for the road, you will still need to get it homologated if you want to enter anything MSNZ event that isnt a motorkhana/autocross.

[NZ_AE86]

If your half cage is built in the right position in the car then you do not need cert. for a WOF. But you will need it homologated for Motorsport.

I would say you would be better off with a full cage as a half cage is worth nothing in a side or front impact which will be most of your track crashes.

[cat007]

Well my aim is to have the car street drivable but safe when I take it to the track. I want to have it all sorted by the end of the year so I've got a few months to save up for a full cage

what's a full cage worth, roughly?

[Bazda]

I got a half cage, really was to strengthen up the rear end as the rear flexed ALOT that i couldn't even open the boot after a run. The half cage def fixed that issue.

I have yet to get it certed or homologated. But will be doing that later this year.

Of course a full cage is better, but then if you use the car every day on the street its prob not practical to have a full cage.

I guess Hunt is just after some added safety, its better than having no cage IMO.

Hunt, go see my fabricator for a half cage.

How much does Homologation cost?

[escortman]

yeh half cages dont need to be certed but need the engineers inspection thingy

[cat007]

Thanks everyone for your replies

If I get a half cage - can, at a later date, be added and changed into a full cage? Or does it have to be ripped out and made from scratch?

I'm also wanting it to strengthen up the chassis a bit. Supra's a pretty solid as it is - but a stiffer chassis wont hurt!

When getting your half cage Barry, how much of the interior did you have to remove? And did you strip it out, or do the fabricator do that for you? i.e. can you turn up with the car in full trim?

[Santa'sBoostinSleigh]

pretty sure you'll need to strip everything back to get it homologated

MSNZ wont homologate a cage unless it is bare steel from what i recall


depending on your cage design and fabracator, but you would generally be looking at starting at $1600+ for a basic full cage

for track use i wouldnt bother with a half cage, all its going to do is help a bit in a roll over, but not really in any other collision

[cat007]

pretty sure you'll need to strip everything back to get it homologated

MSNZ wont homologate a cage unless it is bare steel from what i recall


depending on your cage design and fabracator, but you would generally be looking at starting at $1600+ for a basic full cage

for track use i wouldnt bother with a half cage, all its going to do is help a bit in a roll over, but not really in any other collision

thanks for that. Yeah I assumed I'd have to be the one who strips it out. Which isn't a biggie. Should be able to do that in a day.

Yeah I think I'll go with a full cage. I'm guessing that $1600+ish is for a mild steel one?

[Distrb]

How much does Homologation cost?

$80 (+ logbook fee if you dont have a logbook already)

If I get a half cage - can, at a later date, be added and changed into a full cage?

yep

[d1 mule]

the main hoop has to be at a point in the car where it is impossible to hit your head on it thats the biggie with 1/2 cages. I put one im an old ae85 i had, was good at the time but in hindsight should have done a full cagem and if your gettin it for safety full is the way to go.

gotta be homologated and have seats and all seatbelt points removed, some WoF places even make you get them (the mounting holes) welded up.

can add to a cage once its been homologated, iv done it there is a form to fill out and you have to draw the extentions and take protos of the welds, which then get put in your log book.

and place that does cages will know the wall thicknesses, there are 2 for chromoly and steer i think. From chromoly is thinner as its much stronger but also more expensive

[Bazda]

I did the half cage for now as I dont have the funds to join a proper race series etc. But planning to add the full cage at a later stage.

I got mine in chromolly as I could get the materials through work at staff price.

$80 for a homologation, sweet.

[touge_ae101]

keep in mind the added stiffness in the back of a supra might be fairly minimal when compared to stiffening up a FF car like bazdas. i'd like to think supra's rear end would be fairly well constructed based on some crazy powered ones you see on the net.

but i still think its worth it just from the safety point of view and not too pricey.

its on my list also, hopefully done before megameet.

one thing i am unsure on though is if it needs to be built by a msnz accreditted cage builder or any certified welder/engineer? thought i read something on this a while back but can't remember where.

[Mr Revhead]

I got a half cage, really was to strengthen up the rear end as the rear flexed ALOT that i couldn't even open the boot after a run. The half cage def fixed that issue.

now where is the load transferred to?

[Truenotch]

If I get a half cage, can it be changed into a full cage at a later date? Or does it have to be ripped out and made from scratch?

You can add front stays and side intrusion to a half cage, no problem. To do this you have to make it to the right specs and get a "homologation extension". This basically consists of re-drawing the cage design to the new specs, getting the engineer to fill in a form and having MSNZ sign it off.


The best thing for you to do is go and see a cage fabricator. They will tell you all relevant details and give their opinion on what would be best.


IMO a half cage is still a worthwhile start. They are cheaper, easier to deal with for street driving and you can take passengers so long as they have a harness etc.

[Bazda]

I got a half cage, really was to strengthen up the rear end as the rear flexed ALOT that i couldn't even open the boot after a run. The half cage def fixed that issue.

now where is the load transferred to?

Whats your point?
Where is the load transferred to in any roll cage lol.

[touge_ae101]

little bit off topic here. but was watching a jdm insider vid on youtube the other day and one of the shops over there was drilling the chassis and filling it with urethane of some sort. said it was as good as a cage for stiffening up chassis. has anyone come across this before?

but then again jap cages aren't exactly awesome. lol