Outer Limits 4x4 Board

Well mates down tryin to get his dualcab engineered, asked bout gettin 33's done... No probs $66 more.

Asked about 35's and was told,
"he was told that he can no longer engineer them"
They can no longer be engineered anywhere in aussie.... Apparently they are being told to conform to the new NCOP already, AND to add to it, no 35's anymore...

said:
35s not legal in any state now
says:
they had to go to national ruling
says:
cannot engineer 35s anymore

Thank goodness for national rules.

booooooooo, that sucks
currently chopping the 105 and I was getting it all engineered together 35's etc

I wonder if they can retrospectively change rules? I'm tipping no but i think my Zook is now to be trailered to and from places even when not broken.

ahhhh....about time.

As the value of all pre-placard vehicles skyrockets.

no doubt its been done to death on many forums, but what a croc!!

If the tyre companies are able to produce these to a given standard to be road legal why cant 35's or maybe even 37's be permitted on the road. Its frustrating that these rules are implemented without real consideration of the engineering and safety facts.

Over here in WA there is no such thing as roadworthy checks, unless you get a yellow or need to register a vehicle on the road (flame suit on incase I have that wrong!). If the new national rules had more flexibility to allow larger tyres and bigger lifts and insisted that ALL cars had to undergo yearly or two yearly checks in ALL states you would have greater control over some of the dodgy vehicles on the roads (including normal cars and 4wd's). This might also allow our cops to go about there business relieving them of their duty to give us 4wd's Yellow stickers because they "think" it might be unroadworthy.

By making madatory to carry inspection papers that stipulate the size of tyre and size of lift, it would be easy to determine what has passed inspection. For those that run different size sets of tyres, get inspected twice and carry two certificates.

I am sure there will opinions from others to my thoughts, but on this issue I cant see why rules should differ across the states and territories!

Slunnie wrote:As the value of all pre-placard vehicles skyrockets.

I had that thought

gtir300 wrote:I cant see why rules should differ across the states and territories!

They wont differ... they will be the all god saving national rules.. NCOP. search for it.

-------------------------
also remember if you can find an engineer that hasnt been told this yet, then PM me his name

gtir300 wrote:no doubt its been done to death on many forums, but what a croc!!

If the tyre companies are able to produce these to a given standard to be road legal why cant 35's or maybe even 37's be permitted on the road. Its frustrating that these rules are implemented without real consideration of the engineering and safety facts.

Over here in WA there is no such thing as roadworthy checks, unless you get a yellow or need to register a vehicle on the road (flame suit on incase I have that wrong!). If the new national rules had more flexibility to allow larger tyres and bigger lifts and insisted that ALL cars had to undergo yearly or two yearly checks in ALL states you would have greater control over some of the dodgy vehicles on the roads (including normal cars and 4wd's). This might also allow our cops to go about there business relieving them of their duty to give us 4wd's Yellow stickers because they "think" it might be unroadworthy.

By making madatory to carry inspection papers that stipulate the size of tyre and size of lift, it would be easy to determine what has passed inspection. For those that run different size sets of tyres, get inspected twice and carry two certificates.

I am sure there will opinions from others to my thoughts, but on this issue I cant see why rules should differ across the states and territories!

You will find the major issue with 35's and bigger is that vehicles arent actually 'designed' to run the tyres, brakes, COG, suspension geometry etc etc are engineered at the factory for 31's, rather than the large tyres not being rated.

The issue that is directly related to tyre size is braking ability. It's a genuine issue that people don't usually attend to. On the other hand, it is one that is capable of being dealt with as part of getting an engineering certificate, so it doesn't justify a ban.

The other issues like suspension geometry etc are not, strictly speaking, directly linked to tyre size. They are linked to other changes that people do at the same time ie left, rim offset, etc.

I'm just saying. I don't know the answer here, it seems to me that anything should be engineerable so long as it's actually properly engineered. On the other hand back before everyone switched to 35s and when 33s were huge, the 4WDing fun to be had was good.

WOOT national ruling! Sucks to be anywhere but QLD for once haha!

Although Victorians may think they're at the centre of the Australian universe they may find that not all states intend to adopt the NCOP in all its glory. If it's not written into state legislation, it doesn't apply.

Having said that, I'm in several minds over this one.

1. I despise the lack of choice - if people are determined to have 35s, set some standards. It is possible to engineer 35s into a safe vehicle; this reaction is purely a combination of laziness wrapped in a shawl of arse-covering.

2. As Queenslanders (and Street Machine enthusiasts) will know, banning it doesn't mean it doesn't happen. It simply means it happens uncontrolled - in back yards, without sanity checks.

3. I personally believe that the continual upgrading of tyre sizes is doing nothing more than making the ruts deeper and harder to navigate. 20 years ago people criss-crossed this country on what - 31s? What makes anybody think they need 35s on a road rig? If you want to compete, trailer it - or at least the wheels & tyres.

That's my 3 x 2c - I gross less than $xxg per year, so I don't need to worry about GST.

Bogged, you've massively oversimplified.

The NCOP allows 50mm over the largest placarded tyre for that axle on that vehicle. In the case of a patrol, that's 34. IMHO, that's been the case in Victoria for some time and isn't a new thing. Certainly for us involved with Suzuki's, it's what we've been working with for years.

Yes, it was possible to cert more in the past.

However, it doesn't man for a minute that you can't run a 35 on a patrol. It just demands that you suitably compensate the braking and wheelbearing strength for the added load. Most people aren't interested in pursuing that, so for lots of people that might well mean a 35 is "impossible" but bolt some hummer portal boxes onto suitably strengthened patrol axles and, in theory, a 39 could be legal. Yes, yes, it would also likely exceed the 150mm total lift etc imposed in the NCOP, but you get the idea.

I don't really see the problem - build a stronger car = run more tyre.

In the Suzuki Club, we've dealt with a few engineers over the last four or 5 years and that's been the clear message.

Steve.

Gwagensteve wrote: In the Suzuki Club, we've dealt with a few engineers over the last four or 5 years and that's been the clear message.

Steve.

I think what bogged is saying is that that has changed. Even a suitably modified vehicle (brakes etc) won't be passed by engineers.

Whether bogged is right or not is another story.

The reasons why they have limited the size is the reduced braking ability and wheel bearing failure.

If you are prepared to cough up the coin to 1 up grade these and 2 pay the engineer to mathematically or physically prove your up grades are up to the task, you will get a certificate.

Most engineers will give you a flat no cause they know 99% of the people who fit these tyres are not going to pay for it or go through the effort to make the vehicle comply.

So what does this all add up to well the largest tyre on a patrol from factory is a 7.50-16, which some tyre manufactures are labelling as 235/85/16.

The diameter of these are between 810mm and 818mm add to this the 50mm allowed (NCOP)
This totals 860mm - 868mm

Most 35's are around 880mm, so for your engineers report go and get some that have been buffed down to 868mm, and clean sailing: lol:

The other option is put some diffs out of another vehicle that has a higher GVM and jobs done, seriously.

Enjoy

50mm over the largest tyre for that type of differential, and no exceptions from the people i have spoken to, that includes upgrades to bearings etc. and don't use worn down tyres as they will go by the stated size on the sidewall.

Where has the 35" thing come from? That size is not mentioned in the NCOP. I really the same thing being thrown around years ago - that nobody would engineer over 35's, but there was no written foundation to this and engineers were approving over 35" tyres.

AFAIK the NCOP does not limit the tyre size which can be approved by an approved engineer - but they can not approve a combined lifts over 150mm.

It's got nothing to do with 35's, it's all to do with +50mm.

The limitation is +50mm from the largest tyre approved for that axle, which means no 35's on patrols.

Fathillbilly is 100% on the money.

Tyre size is derived from the tyre and wheel handbook, not what you have on the car, so you can't find some 32" tall tyres with "35" on the sidewall and use them to get a cert claiming you have 35's.

dogbreath, no, that's not a change for victoria AFAIK ( unless we are talking over about 10 years ago) . It has always come down to bearing strength and braking and engineers aren't interesting in over a 50mm increase, even allowing for heavy axles under a light car.

A good example - Nigel Gamblin's land rover/range rover hybrid was certed about three years ago on 38" swampers. That's only a +50mm increase from the donor axles, nominally from an FC101 Land rover that was designed to run 9.00X16 tyres (36") from the factory. It was also a '72, so no ADR on tyres, making DOT e4 rated swampers legal.

Trust me, if it was possible to cert more than a +50 increase, that car would have had it.

As I said, IMHO, there's been no recent change.

Steve.

never understood this "engineering crap" so how do u engineer 35's? just write its ok and sign it? like wat do u do to make them ok on a 4wd?


im in qld btw.

money_killer wrote:never understood this "engineering crap" so how do u engineer 35's? just write its ok and sign it? like wat do u do to make them ok on a 4wd?

Not the end of the world, most guys run 35's un-engineered on patrols now, and will continue to do so.

The rest will have to run 34's (boohoo, big difference)

Watch all the tyre companies start pumping out 34's now! They will be in higher demand = more choice + lower prices.

money_killer wrote:never understood this "engineering crap" so how do u engineer 35's? just write its ok and sign it? like wat do u do to make them ok on a 4wd?


im in qld btw.

The reason you don't understand is it is illegal in QLD. QLD rules on a solid axle 4x4 (F+R) are 25mm larger, no ifs, no buts, no engineer or mod plate required.

The NCOP if adopted in QLD will allow +50mm.

ISUZUROVER wrote:

money_killer wrote:never understood this "engineering crap" so how do u engineer 35's? just write its ok and sign it? like wat do u do to make them ok on a 4wd?


im in qld btw.

The reason you don't understand is it is illegal in QLD. QLD rules on a solid axle 4x4 (F+R) are 25mm larger, no ifs, no buts, no engineer or mod plate required.

The NCOP if adopted in QLD will allow +50mm.

i am aware of that but how is ur 4wd "engineered" for 35's ? wat is done besides, a written piece of paper?

It does not matter what rules they bring in - there are plenty of people who are either ignorant or dont give a damn. Seen plenty of huge tyred fourbys registered in Qld - and not just on highly modified trucks, also on obviously daily drivers...

joeblow wrote:

money_killer wrote:never understood this "engineering crap" so how do u engineer 35's? just write its ok and sign it? like wat do u do to make them ok on a 4wd?

Well, in SA:

To go from 30" tyres (standard) to 33" tyres with +20mm track, plus 50mm body lift plus 50(ish)mm of suspension lift, I had to have an engineer's report covering speedo accuracy, braking & lane change.

Speedo accuracy was a simple comparison against his GPS.

Braking included 15 repeated 0.5G stops, braking with one side on bitumen/one side on dirt & measurement of pedal pressure during an emergency stop from 100km/h.

While circling the race track he bounced it off curbs on both sides (to test steering kickback), then performed an "18 cone lane change test" - using the same markers on the same track that the Mitsubishi factory (used to) use to test cars under development.

The Paj passed with flying colours, with the rear sway bar sitting on the ground alongside the track.

To also include a GVM increase, the engineer wanted to disassemble front & rear axles, measure, calculate, then decide if he would certify heavier. I didn't do that.

money_killer wrote:

ISUZUROVER wrote:

money_killer wrote:never understood this "engineering crap" so how do u engineer 35's? just write its ok and sign it? like wat do u do to make them ok on a 4wd?


im in qld btw.

The reason you don't understand is it is illegal in QLD. QLD rules on a solid axle 4x4 (F+R) are 25mm larger, no ifs, no buts, no engineer or mod plate required.

The NCOP if adopted in QLD will allow +50mm.

i am aware of that but how is ur 4wd "engineered" for 35's ? wat is done besides, a written piece of paper?

Its assessed by an engineer to make sure that its safe from an engineering and dynamics perspective, it complies with the rules and regulations and then its blue slipped to check its all in properly so the rego papers can be modified to reflect the changes. At the end of the day it is just a bit of paper, but there is a process to get it.

cool thanks for clearing it up ppls.

Unless I am misreading the NCOP. The section that people are quoting is section 4. MODIFICATIONS WITHOUT CERTIFICATION
Item 4.2 - Non-Standard Tyres And Rims

This has nothing to do with engineering. It is what you will be able to do without having to involve an engineer.

Even a legal increase to 33" tyres in QLD will be a good thing.
Will also make running 35's easier.

ISUZUROVER wrote: no ifs,

Spoton. Here in QLD we only know solid axles.

God forbid if we all have to drive on small tyres it may actually bring back a bit of driver skill. With track closures that are, and will go on, it may make some "lesser" tracks more of a challenge as well.