Offroad-Express

Been advised that if I put in a cage (front 1/2 exo), the longitudinal rear braces from the main hoop to the floor will mean it won't certify with the rear seat in place (please assume that main hoop isn't a problem in itself, and that the diagonal crossbrace would be removable). This is going into a BJ70 club truck which has placements for three rear seatbelts. The way I measure the LVVTA specs (and I'm always right ), it is achievable - but the certifier has advised otherwise, padded or not (smashed-elbow-concern)... Then again, the early Prados only have accommodation for two in the rear - with outer armrests and, having a had look at my mate's, this seems to give hee-yips of leeway, so maybe if I can steal his seat...?? Any help with this would be appreciated.

hmmmm... was this a dumb question or are they shy???

I was faced with same problem. To start with I just had a roll bar behind the front seats. You can view a picture in "bulletproof " hilux spec " under new members.
The Certifier told me this was not allowed because I had to have a 4 point mount with angle braces. The other condition was that I had to remove the rear seat because of impact injuries. I had no choice so removed the seat.
This is probably not over the top as much as it seems.
One day on a 4x4 trip before I removed the seat, a friend jumped in the back. We went through a washout that I did not see from the drivers seat and he cracked his head quite hard on the bar.

Bulletproof

Hmmm, not so sure that either of the certifiers are correct. The rollbar rules are specific to MC class vehicles ie 4x4.
There are no specifics in the LVVTA or LTNZ rules as to the mounting of a rollbar for a 4x4. The specifics are for the frontal impact Standards and the tolerances are pretty reasonable. Padding is required but is not a factor in the measurement of the required tolerance. The Standards can be found at lvvta.org,nz
The removal of the rear seat is not required if the frontal impact rules can be met. (Otherwise every Jeep wrangler would have to lose its back seat just because the factory fitted a rollbar !)

PeterVahry wrote:Hmmm, not so sure that either of the certifiers are correct. The rollbar rules are specific to MC class vehicles ie 4x4.
There are no specifics in the LVVTA or LTNZ rules as to the mounting of a rollbar for a 4x4. The specifics are for the frontal impact Standards and the tolerances are pretty reasonable. Padding is required but is not a factor in the measurement of the required tolerance. The Standards can be found at lvvta.org,nz
The removal of the rear seat is not required if the frontal impact rules can be met. (Otherwise every Jeep wrangler would have to lose its back seat just because the factory fitted a rollbar !)

I have just rung up my certifier in nelson and he said it is not in LVVTA web site but in a book they have with specific drawings for 4 and 6 point mounts . I am quite welcome to it so will have to go for a drive and will get back to you.

I'll check my LVVTA Hobby Car Technical Manual this evening. (He might be right)

if you are going to a certain certifier in your area and he has told you not to do it, and he will be the one certifying your vehicle, then it makes sense to listen to him.

so I would do as he says, unless you are taking it somewhere else, then I would ask that guy.

as with any project in any form, it pays to keep in contact with your cert guy to make sure you are doing things properly so as to avoid having to redo stuff later

I have just gone in to my certifier and told him I couldn't find any thing on the LVVTA site about roll bars. He said you will not find it there. The standard they use is the one found in the " NZHRA CODE OF CONSTRUCTION MANUAL"

These are the relevent pages photo bucket has cut the sides off. to see full page save as





Also used is the "NZ HOBBY CAR TECHNICAL MANUAL"

This is the section they use over 2 pages



next page



I hope this sheds some light on the subject. I was also made to weld up all seat and seatbelt mount holes as well.

Richard

Unfortunately not all certifiers read all the rules and keep up to date. There is a drawing of rollbars in the old " Code of Construction Manual" but that document has been superseded by the "Hobby Car Technical Manual" which itself conforms to the Interior Impact Standard as found on the LVVTA website http://www.lvvta.org.nz/stdInteriorImpact.pdf

( I have a copy of both the manuals) Rollbars are allowed in 4x4 (MC class) vehicles and how they are built is not subject to certification except in terms of the Interior Impact Standard.

I see I replied at the same time as the old data was posted. That certifier should not be working from that manual... it is outdated!

PeterVahry wrote:Unfortunately not all certifiers read all the rules and keep up to date. There is a drawing of rollbars in the old " Code of Construction Manual" but that document has been superseded by the "Hobby Car Technical Manual" which itself conforms to the Interior Impact Standard as found on the LVVTA website http://www.lvvta.org.nz/stdInteriorImpact.pdf

( I have a copy of both the manuals) Rollbars are allowed in 4x4 (MC class) vehicles and how they are built is not subject to certification except in terms of the Interior Impact Standard.

I see I replied at the same time as the old data was posted. That certifier should not be working from that manual... it is outdated!

This is the information my certifier gave me today. I have been through 3 certs. and when my bar was done about 8 years ago the rules may have been different so is probably irrelevant what I say.

Richard

Hey thanks guys. Skid, I hear you!

skid wrote:if you are going to a certain certifier in your area and he has told you not to do it, and he will be the one certifying your vehicle, then it makes sense to listen to him.

so I would do as he says, unless you are taking it somewhere else, then I would ask that guy.

as with any project in any form, it pays to keep in contact with your cert guy to make sure you are doing things properly so as to avoid having to redo stuff later

I am not brave enough to upset me cert man! However, that doesn't mean I'm not up to pushing my case enthusiastically if I feel I have a reasonable cause to 'argue'. Basically the back seat's coming out anyway for any decent trips - too bloody heavy and limits the size of the bacon and egg pie I can get in the back. It's just that it's really handy to throw back in sometimes.

Now, reading the LVVTA info (spec. 16.4.2 etc., in the Interior Impact info above), they are very definitely stating that they allow (adequately padded) roll cages to infringe on the 'B'-zone, which is where the two stays for the main hoop go as they run from the top of the main hoop on each side down past the rear seat passengers' elbows (but obviously with a bit of room to spare...) to the floor behind the rear seat. If this is incorrect, then the whole thing needs clarifying. Cheers.

Cutbak wrote:Been advised that if I put in a cage (front 1/2 exo), the longitudinal rear braces from the main hoop to the floor will mean it won't certify with the rear seat in place (please assume that main hoop isn't a problem in itself, and that the diagonal crossbrace would be removable). This is going into a BJ70 club truck which has placements for three rear seatbelts. The way I measure the LVVTA specs (and I'm always right ), it is achievable - but the certifier has advised otherwise, padded or not (smashed-elbow-concern)... Then again, the early Prados only have accommodation for two in the rear - with outer armrests and, having a had look at my mate's, this seems to give hee-yips of leeway, so maybe if I can steal his seat...?? Any help with this would be appreciated.

If you have a look at my picture. I have made the stays so they are hinged at the mount behind the seat which is a lot more user friendly for loading the truck.



I hope this helps and if you want a photo of the rear mount I can give you one tomrrow.

Richard

Comment received today from the head of LVVTA....

Hi Peter,

The only aspect that the LVV certification process is interested in, in
relation to rollbars and roll cages, is interior impact. As road going
vehicles, there is no need for any particular strength requirements to be
applied. We rely on the individual sporting organisations (such as NZFWDA,
MSNZ) to provide the strength requirements for their particular application.

The details in the old NZHRA Code of Construction Manual were only a
recommendation to help hot rod builders gain some roll-over protection for
fiberglass-bodied vehicles.

Rear seats can be kept and used provided that the A-zone interior impact
requirements are met, as set out within LVV Standard 155-40.

You're welcome to quote this, or have the affected party forward it onto
Brent the LVV Certifier. brent can call me if he needs any further
clarification.

Hope that helps.

Cheers, Tony.

PeterVahry wrote:Comment received today from the head of LVVTA....

Hi Peter,

The only aspect that the LVV certification process is interested in, in
relation to rollbars and roll cages, is interior impact. As road going
vehicles, there is no need for any particular strength requirements to be
applied. We rely on the individual sporting organisations (such as NZFWDA,
MSNZ) to provide the strength requirements for their particular application.

The details in the old NZHRA Code of Construction Manual were only a
recommendation to help hot rod builders gain some roll-over protection for
fiberglass-bodied vehicles.

Cheers, Tony.

In my case the reason I fitted a roll bar was because in Nelson we do alot of steep firebreaks that go up 100s of feet and sometimes you end up sideways so i wanted a bit more protection behind the drivers seat.This is not like trials where every bank is limited in height.
So instead of reinventing the wheel , I thought I might as well copy a design that had already been worked out and that is what I did. But had to remove the seat to comply with the LVVTA impact areas.
A friend of mine Paul Delis is the Fire Chief at Kaiapoi and he said that even though mine looks and is strong it would be completely useless after 2 or 3 rolls because as the momentum builds in a roll with 2 tonne of truck crashing on it, any mount will punch through the floor pan. My certifier also said I should have a full harness seat belt but that didnt come under LVVTA.

So it raises questions about why we have a roll bar. I still feel more comfortable with it, but it is probably just giving me a false sense of security and wont be any good if put to the test.

Richard