Forbidden Suspension Mods

[andyrover]

I just picked up the latest Overlander mag which made reference to July article by Mark Allen on D3 suspension mods not recommended by LR. Also quoted some tricky device by Andrew Trafford, no further details. Any clues?

I can see a possible area of improvement in upping the sit-down speed from 40 kph as it could reduce transit times past Big Red. Also seem to recall a while ago a bit of trickery to fool the EAS computer to rise higher than factory settings eg. for serious crawling over rocks. Could be useful?

[rmp]

I forget which issue that was, but it wasn't the latest which is November (just out), it was 3-4 months back.

The device in question is an in-cabin method of changing the length of the sensor rods from Mitchell Bros. CD3 will be along shortly to explain it.

The D3/RRS warns at 40kmph and actually lowers at 50.

While all manufacturers take a dim view of any aftermarket accessories (at least in Australia), it is very rare for one to make the sort of statement Land Rover did and specifically call out a modification as unsafe.

Refer to various other threads here for more on the issue.

[andyrover]

OK, thanks, found it way back on page 10 somewhere and it looks interesting, shortening the height sensor rods would trick the system into thinking the car is lower than it actually is. This got me thinking a couple of things: Thing 1 - it's all good, who needs access height anyway? but then came Thing 2 - what else is being affected by fooling the system? For normal driving, the computers must think you are drivng around at access height all the time, unless they don't allow that and lift the car to 'normal' height automatically, which of course is now really extended height!

To quote from the Oct Overlander p.18: "The device described by Mr Trafford is strongly opposed by Land Rover as it is unsafe and interferes unlawfully in the air suspension system of the vehicle and with the braking system." I am prepared to dismiss the comment about 'unlawful interference with the air suspension system' as more of the same nanny state meddling we saw in NSW by the RTA recently, but I do worry about affecting the brakes in some way (in any way, in fact!). Any thoughts?

[Leo]

Slightly shorter rods make no difference to braking. I think LR are just covering themselves if anything does happen.

If you are still in warranty and do use shorter rods, don't let the dealer know.

[Blknight.aus]

doesnt make any difference to braking?

sure, you peg a lifted vehicle into a hard corner under brakes see how unaffected your braking is....

remember you're dealing with air suspension not spring steel or lift blocks doing this stuff.

changing the amount of air in an airbag changes not only its height but its characteristics.

dont believe me?

try it with tyres first get a handfull of differnt size and shape tyres weight them to the same mass, inflate them to the same pressure and drop them off of a cars tailgate and watch what happens..

now change the pressure.

notice anything different.

Although the scale isnt the same the same changes apply to your airbags.

[andyrover]

Thanks, fairly obvious but not quite what I had in mind... For instance, Terrain Response changes settings to ABS and has some interaction with the suspension height (I think). If only ABS is affected, I'm not that worried but I would like to know of any other effects on braking before modifying...

[Leo]

doesnt make any difference to braking?

sure, you peg a lifted vehicle into a hard corner under brakes see how unaffected your braking is....
.

I get what you're saying, but on the D3 and RRS, there is negligible difference in braking distance (if any) whether in normal height or off-road height. Putting 100kg of stuff in the back will have a greater effect.

andyrover: shortening the suspension rods has no effect on terrain response. As far as the computers are concerned, you're at normal height.

[Blknight.aus]

the main reason its forbidden is because thats not the way its designed.

altering any aspect of the suspension alters all the maths on how the vehicle was set up. Some car manufaturers even go down to the level of specifying the exact standard of tyre you can have on the car (porsche) for similar reasons. so even ignoring the extra loading and stress you can put on the suspension components by pushing them up further and all the other stuff that changes position on the driveline itself (hands up everyone who did a 2 inch lift on a disco with a rubber donut) by changing the height, stiffness, spring rate, leverage points and/or all the other fun aspects that get poked into computer programs these days to work out how a vehicle should handle you are going into places that the designer didnt design into the thing.

Prang a modded one and you're exposing yourself, the dealer, the car makers, the bloke who made the parts, the bloke who fitted the parts, the cop who pulled you over and failed to notice the vehicle was illegal, your dog, its fleas, someone you met on the street who encouraged you to keep the mod because it looked cool, mrs jones at number 42, the last mechanic to work on your vehicle, the guy who didnt defect it on its last inspection for roadworthy, his boss for not ensuring that it was suitabley defected and at least 12 other totally random people who are not related to you or the vehicle to litigation and lawsuits.

Blame it on the Americans and their "I can get rich quick by being ignorant and suing someone else for my stupidity" I do.

[daveyb]

Does anyone have a link to this Mark Allen article? I can't seem to find it. Interesting. Interesting.

[CaverD3]

As there are shortened and adjustable rods available; the original idea was to allow the shortened rods to be driver chosen. This would allow the factory setting to be the default setting. A return to factory settings being better (and safer) than permanent shortened rods.
The system has been tested in the Simpson and outback Queensland and has proved robust and effective.
However once the system was mentioned in the mainstream press LR Aust immediately set some lawyers onto myself and Mitchell Bros. Yes andyrover they used the never enacted VSI 50 to justify their argument. LR are within their rights to refuse a warranty claim if they believe a modification caused the failure (fair enough). It should be at your own risk.
We are trying to ensure the system is legal and are talking to engineers. We will eventually need to talk to LR and are happy to talk directly.
The system gives an extra 30mm of lift at normal height and correspondingly higher heights at other settings when activated. So it is well within the current supension modification height in the code of practice.

Davey this is the original:



I'll see if I can dig up the Overlander response to LR.