Air Bags,don't Go There

Aaron Schubert

Moderator
You could put a solid block of wood between the axle and chassis on any car and it will still go down at the back and up at the front if you put too much weight too far back behind the axle. You must have a hell of a lot of heavy things in the back if you think the heavy duty model will still be not good enough.

Whether something breaks or not will depend a lot on where you drive it and at what speed. Swaggie said he has been driving in the VHC for years and has not broken anything. There is no speed involved in those conditions. I have seen many people on forums ask about suitable cruising speeds on Outback roads but never in the mountains for obvious reasons.

Whatever obstacle you hit on the road be it a rock ledge on a bush track or a hole at a cattle grid will send a certain amount of force up into the car. Those forces increase by the square of the speed. A big hole at the approach to a cattle grid or a deep washout will send up forces sixteen times higher if you hit them at 80 kph than at 20 kph. That is what breaks so many overloaded or incorrectly loaded cars in the Outback.

I think far too many owners are lulled into a false sense of security by aftermarket suspensions, big wheels etc that come with all kinds of must have advertising. They head of into the Outback thinking they have a built a "tough tourer" that is indestructible.

I hear you mate. I still disagree with the factory suspension being suitable. I'll get it all weighed when the build is done and we will know for sure.

Aaron
 

2luxes

Well-Known Member
I hear you mate. I still disagree with the factory suspension being suitable. I'll get it all weighed when the build is done and we will know for sure

Just make sure you don't over do it. I have seen far too many mechanical breakages in modified cars starting from the days before 4wds became popular for recreational purposes.

This story below was in an NRMA magazine a few years ago. I am not trying to sell you a Hilux but look at the first column and see what Toytota goes through to build the things. I would imagine the other manufacturers do something similar but perhaps not all of them on that scale. You can bet they did not break those cars in less than 20,000 ks by driving them in Sydney or Melbourne. They would have had the living daylights thrashed out of them on all kinds of mountain and desert tracks.

All the manufacturers know exactly what they are doing and the cars will do what they have designed them to do. If an owner wants them do do more then no problems but they are on their own and somethings might break. The worrying part about it is nobody knows if their heavily loaded car is going to survive or not when they take off into the bush.
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Aaron Schubert

Moderator
Just make sure you don't over do it. I have seen far too many mechanical breakages in modified cars starting from the days before 4wds became popular for recreational purposes.

This story below was in an NRMA magazine a few years ago. I am not trying to sell you a Hilux but look at the first column and see what Toytota goes through to build the things. I would imagine the other manufacturers do something similar but perhaps not all of them on that scale. You can bet they did not break those cars in less than 20,000 ks by driving them in Sydney or Melbourne. They would have had the living daylights thrashed out of them on all kinds of mountain and desert tracks.

All the manufacturers know exactly what they are doing and the cars will do what they have designed them to do. If an owner wants them do do more then no problems but they are on their own and somethings might break. The worrying part about it is nobody knows if their heavily loaded car is going to survive or not when they take off into the bush.
View attachment 51930

Cheers. Yep. The focus is on simplicity, functionality, price and of course weight.

Aaron
 

2luxes

Well-Known Member
Cheers. Yep. The focus is on simplicity, functionality, price and of course weight.

Yes they are all built to a price except maybe a McLaren or a Bugatti. The amazing part about it is after all these manufacturers have spent countless millions and five or six years designing, developing and testing these utes, they can't put a suitable suspension in them. At least the people who buy them for work in either cities, rural areas or the Outback seem happy enough. So are the vast majority of families. It just seems to be a tiny percentage of city based tourists that have all the trouble. They then turn to the aftermarket industry and don't the bush repair workshops love them.
 

muc the truck

Well-Known Member
I have bee saying this for years and been shouted down in my place simply because I am no engineer . But hey I agreed all the time with the last Quote--- REPORT CONCLUSION

The Syngeering Pty Ltd report concluded:

".... AIRBAGS HAVE LITTLE TO NO EFFECT ON THE DISTRIBUTION OF STRESS WITH THE CHASSIS RAILS".... "THE RESULTS INDICATE THAT IN EVERY LOAD CASE INVESTIGATED THE ADDITION OF AN AIRBAG BETWEEN THE CHASSIS RAIL AND LEAF SPRING DOES NOT INCREASE THE MAXIMUM STRESS THROUGH ANY SECTION OF THE CHASSIS RAIL"
 

2luxes

Well-Known Member
muc

That report also says this.

Secondly, chassis cracks or damage occurs when a vehicle owner/driver exceeds the weight and loading recommendations as set out by the vehicle manufacturer. A lot of people think they only have to worry about GVM, but they are many other factors at play

No chassis is going to bend or break if it is being used within its design limits. They break because they are being used outside their limits and the reason why so many owners take them outside those limits is they are lulled into a false sense of security. They think they are doing the right thing when faced with an endless amount of after market suspensions that are usually advertised as the solution to their load carrying problems. This is backed up by countless people on net forums telling them that is the way to go.

These suspensions or air bags will certainly carry the extra load but the rest of the car, including the chassis, is still standard. When chassis, axle housings, wheel studs or wheels break, the aftermarket springs or air bags still look brand new.

I would like to see some statistics on the ratio of bent chassis with air bags and no bags but stiffer springs. From my own observation in the bush and in magazine/net photos, the ratio would be about ten to one in favor of air bags. The things are exponential springs, not linear springs. The more you compress them the more they resist further compression.

A linear leaf spring bends into a reverse arc under a heavy load in corners as part of the roll understeer handling stability feature of the whole suspension design. An air bag acts like an oversize bump rubber and stops the leaf springs from working properly. Bump rubbers are also exponential.

Collyn Rivers https://caravanandmotorhomebooks.com/collyn-rivers/ said many years ago on another forum that they can be useful for softening the ride on an empty ute but they are not for carrying extra loads or raising sagging rear ends. In other words use them with a low pressure to lift the empty ute slightly off its springs but get the pressure out of them and let the springs do their work when the car is loaded.

When you use them with the usual 20 up to who knows what psi with a load on the back, a falling or suddenly rising chassis just bends down behind them as they start rapidly hardening. This is why every bent chassis that I have ever seen with air bags has bent within an inch or two of the top of the bags. Those without them bend up near the front hanger for the spring. That is the last point of resistance as the chassis goes down hard behind the axle and tries to jerk the front wheels off the ground.
 

muc the truck

Well-Known Member
muc

That report also says this.



No chassis is going to bend or break if it is being used within its design limits. They break because they are being used outside their limits and the reason why so many owners take them outside those limits is they are lulled into a false sense of security. They think they are doing the right thing when faced with an endless amount of after market suspensions that are usually advertised as the solution to their load carrying problems. This is backed up by countless people on net forums telling them that is the way to go.

These suspensions or air bags will certainly carry the extra load but the rest of the car, including the chassis, is still standard. When chassis, axle housings, wheel studs or wheels break, the aftermarket springs or air bags still look brand new.

I would like to see some statistics on the ratio of bent chassis with air bags and no bags but stiffer springs. From my own observation in the bush and in magazine/net photos, the ratio would be about ten to one in favor of air bags. The things are exponential springs, not linear springs. The more you compress them the more they resist further compression.

A linear leaf spring bends into a reverse arc under a heavy load in corners as part of the roll understeer handling stability feature of the whole suspension design. An air bag acts like an oversize bump rubber and stops the leaf springs from working properly. Bump rubbers are also exponential.

Collyn Rivers https://caravanandmotorhomebooks.com/collyn-rivers/ said many years ago on another forum that they can be useful for softening the ride on an empty ute but they are not for carrying extra loads or raising sagging rear ends. In other words use them with a low pressure to lift the empty ute slightly off its springs but get the pressure out of them and let the springs do their work when the car is loaded.

When you use them with the usual 20 up to who knows what psi with a load on the back, a falling or suddenly rising chassis just bends down behind them as they start rapidly hardening. This is why every bent chassis that I have ever seen with air bags has bent within an inch or two of the top of the bags. Those without them bend up near the front hanger for the spring. That is the last point of resistance as the chassis goes down hard behind the axle and tries to jerk the front wheels off the ground.


Did you think I didn't read the whole article lol Being a truckie for a while I get the gist of loading correctly better than the average car driver . I get that you don't like air bags , I do . I love how I drive around most of the time empty with a smooth ride and inflate them every time I go on a trip so I don't have to readjust my povo pack Colorado's headlights on a trip to stop them blinding everyone . I level the vehicle for stability and road handling and loved it on the windy ice capped roads in vic and nsw snow a few years ago . I have my cake and eat it too thanks . I can drive empty in reasonable comfort for a bony old leaf rear and drive fully loaded and at highway speed have about the same feel in the hands on the wheel were as before laden I was a good 40-50mm higher in the front loaded blinding cars with the body roll of a land rover with the sway bars disconnected . I will leave it too you to chase your own statistics as any I give you would be biased , I have only had one air bag equipped car and I haven't bent it yet. Your quote used -In other words use them with a low pressure to lift the empty ute slightly off its springs but get the pressure out of them and let the springs do their work when the car is loaded. That's not what any one with air bag does and goes DIRECTLY against every single air bag helper kit instructions sold in Australia AND USA . all use a standard rate of spring and bugger all air pressure in the bag when TRAYS empty and enjoy a smooth ride and when we load up ( DISTRIBUTED ) we raise the air bag pressure and give that steering control back and reduce the body roll. In essence making the vehicle safer than that with the same load and no air bag helpers . I cant understand your idea of increasing spring rate when empty to make it more comfortable by as you quote suggests because its not how you think it is in real life . I deflate when I empty or run low pressure letting your leafs do the work and I increase pressure with load so the bags help the leafs . What the air bag helper kits do when used correctly is share load at the higher ride height so load carried without the sag just like stiffer springs . Not one kit sold take all load way from the leaf set up and stop leaf rebounding as a spring its still a spring just a higher spring rate for as long as the air pressure is there and as you have just read in the articles engineer report above it doesn't overstress the chassis as load is shared in 3 places not 2 (load is not in one place like you have imagined ). Airbag helper kits sold in Australia simply give us all more control and flexibility via air pressure . We are not simply stuck with a rough truck from those 500 kilo constant rated springs all year around when you only load up for trips a few times a year for a portion of your kms and we are not stuck during those times with a bad handling vehicle either . I know people have killed there chassis with airbags and NO air bags ,instead coils, leaf and torsion but the driver is what caused it. The driver does all the damage by driving badly for the conditions or lack of corrosion preventative , ignoring load distribution rules and manufactures ratings. statists will only say the same thing . The driver caused it . If statistics said airbags caused it ,well they would not be legal in 7 states and territories would it ? I don't know why more people are not buying 4x4 Isuzu trucks . They are cheaper new than a landcruiser . A brand 7 seater nps75/45-155 hi/ low 4x4 crew cab with 19.5 single alloy wheels is under 80 grand lol .
 
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2luxes

Well-Known Member
quote] I get that you don't like air bags ,

They are fine when the car manufacturers design them as an integral part of their suspension design. What I don't like is the damage that often results when people put them into a suspension and chassis that has not been designed to work with them.

That's not what any one with air bag does and goes DIRECTLY against every single air bag helper kit instructions sold in Australia AND USA .

That comment came from a man who was employed by General Motors to design, build and use electronic testing and recording equipment in suspension development. He has studied the subject and written about it ever since. Can you name any car manufacturer who recommends air bags for use in their products or has them available as an over the counter optional extra?

all use a standard rate of spring and bugger all air pressure in the bag when TRAYS empty and enjoy a smooth ride and when we load up ( DISTRIBUTED ) we raise the air bag pressure and give that steering control back and reduce the body roll. In essence making the vehicle safer than that with the same load and no air bag helpers .

Lifting a heavily loaded rear end back up again is the exact opposite to what the car manufacturer intended and will make the car more difficult to control for the vast majority of drivers. It cancels out the roll understeer feature of the original design making the car prone to sliding its tail out in corners instead of the front running out wider. That is the way just about every car since the 1950s or maybe even earlier has been designed that way. The manufacturers set them up like that because very few drivers can confidently control oversteer. https://www.google.com.au/search?q=...-g1MnZAhWIxLwKHYjyDHEQsAQIKw&biw=1920&bih=974

Rear leaf springs are always mounted with the front shackle down low and the rear up high. They are flat when fully loaded and go into a concave shape when the car leans over in a corner. It is supposed to have some degree of body roll. This changes the angle of the axle housing and causes the outside wheel to toe in slightly and the inside wheel to toe out. This helps to maintain the front to rear tyre slip angle ratio so the car will still understeer as intended.

Loading up the rear end creates oversteer. The suspension design reduces it. You will stuff up this vital handling feature if you load up the rear end then lift it back up again.

If all a suspension had to do was keep each end of the car up off the ground and allow the wheels to rise and fall on uneven surfaces then cars would not need anything better than what was in use a century ago. There is a hell of a lot more to their design than what you can see by just looking

Everything you have written is based on personal opinion. It does not change the fact that there are countless overloaded or incorrectly loaded cars running around the bush with owners who think they have done the right thing by installing aftermarket suspension parts. Some will get away with it but unfortunately many won't. At least a bent chassis in not likely to kill anybody but a roll over in which suspension alterations have been a contributing factor can.

My only interest in this is safety and trying to stop people from breaking their cars. There is nothing wrong with modifying suspension providing you know exactly how they work in the first place and what your alterations are going to do to it. Thinking the car will feel better and look better is not good enough.
 

muc the truck

Well-Known Member
They are fine when the car manufacturers design them as an integral part of their suspension design. What I don't like is the damage that often results when people put them into a suspension and chassis that has not been designed to work with them.



That comment came from a man who was employed by General Motors to design, build and use electronic testing and recording equipment in suspension development. He has studied the subject and written about it ever since. Can you name any car manufacturer who recommends air bags for use in their products or has them available as an over the counter optional extra?



Lifting a heavily loaded rear end back up again is the exact opposite to what the car manufacturer intended and will make the car more difficult to control for the vast majority of drivers. It cancels out the roll understeer feature of the original design making the car prone to sliding its tail out in corners instead of the front running out wider. That is the way just about every car since the 1950s or maybe even earlier has been designed that way. The manufacturers set them up like that because very few drivers can confidently control oversteer. https://www.google.com.au/search?q=...-g1MnZAhWIxLwKHYjyDHEQsAQIKw&biw=1920&bih=974

Rear leaf springs are always mounted with the front shackle down low and the rear up high. They are flat when fully loaded and go into a concave shape when the car leans over in a corner. It is supposed to have some degree of body roll. This changes the angle of the axle housing and causes the outside wheel to toe in slightly and the inside wheel to toe out. This helps to maintain the front to rear tyre slip angle ratio so the car will still understeer as intended.

Loading up the rear end creates oversteer. The suspension design reduces it. You will stuff up this vital handling feature if you load up the rear end then lift it back up again.

If all a suspension had to do was keep each end of the car up off the ground and allow the wheels to rise and fall on uneven surfaces then cars would not need anything better than what was in use a century ago. There is a hell of a lot more to their design than what you can see by just looking

Everything you have written is based on personal opinion. It does not change the fact that there are countless overloaded or incorrectly loaded cars running around the bush with owners who think they have done the right thing by installing aftermarket suspension parts. Some will get away with it but unfortunately many won't. At least a bent chassis in not likely to kill anybody but a roll over in which suspension alterations have been a contributing factor can.

My only interest in this is safety and trying to stop people from breaking their cars. There is nothing wrong with modifying suspension providing you know exactly how they work in the first place and what your alterations are going to do to it. Thinking the car will feel better and look better is not good enough.
If you had any interest in safty what so ever you would not woffal on with lies about you falsy believe some one elses car hadles with air bags. Its clear you don't have them . Its clear you don't drive on them and its clear you don't see ANY safety merits in them and its very clear that you don't see them as a spring with a higher rate just like any other spring made of steel that also greatly improves handling when the spring rate is increased Just lie pedders heavy duty spring kits for passenger (coil equipped cars and 4x4) for example . increase in spring rate takes away body roll and give a more direct vehicle to control. What a load of rubbish your last post is . You dive in there and clutch with straws. When I said it removes body roll with air bag helpers you say its supposed to have body roll as if the bags have taken all of it away in an over reaction . When really its handles no different loaded as someone fitting stiffer springs only difference is instead of removing those springs and replacing them with the standard ones when the hard works done I let air pressure escape . Start giving merit were merit is due because when used correctly there is nothing wrong with any air bag helper kit . Its saved accidents not increased them. How you will ask . Answer by making the vehicle more direct and responsive evading accident just like adding fe2 suspension to a commodore. your argument might say but hoons buy fe2 suspension and cause more accidents because of the way they drive ( higher insurance premiums ). True so we ban Fe2 suspension options . and that's the same about air bags people don't drive and treat there car in accordance with vehicle sympathy and laws so you say we should not have air bags on vehicles not made standard with them , people bust there cars all the time being an ass to them even regular innocent hard working people that never read a forum , don't own a 4x4 go to church and mow there elderly neighbours lawn . If you really want to target a group over safety how about you start in your local shopping centre and look at all the bald tyres and worn out brake pads but don't lecture me and tell me that vehicles fitted with air bag helper kits including mine is more dangerous due to air bags than stock standard .

Everything you have written is based on personal opinion. It does not change the fact that there are countless overloaded or incorrectly loaded cars running around the bush with owners who think they have done the right thing by installing aftermarket suspension parts. Some will get away with it but unfortunately many won't. At least a bent chassis in not likely to kill anybody but a roll over in which suspension alterations have been a contributing factor can.

I want you to stop this bantering because all it says is there are fools you defend on this planet that no one can help, if they cant load a car or 4x4 they should not drive , if they overload while out bush in remote places they should not drive , Stop defending stupid people that will not follow instructions or laws and give credit were credit is due for air bag helper kits that are designed by engineers THE CREDIT THEY DESERVE - Instead of bagging out Australian and USA business ventures pardon the pun how about bag out the idiots that overload and do not distribute the load and teach them but I wont hold my breath. Because you cant teach ignorant people that don't want to learn anything they don't want to learn. Its hard enough to get everyone to change there tyres, brake pads and rotors in Australia .


Oh by the way my leaf springs still will concave around a corner it just means I can drive that corner faster due to the higher spring rate before they do just like the bogan in the commodore with his fe2 coils can go faster around the corner the sales rep in the base model .

 

Jackolux

Well-Known Member
I have been driving 4WD's for donkeys years and have plenty of mates that have also , all of em have had aftermarket suspension a few have had AirBags and yeah many have been over GVM , just about everyone I know has changed their suspension ,
To make this claim , I think is just bull .
( Lifting a heavily loaded rear end back up again is the exact opposite to what the car manufacturer intended and will make the car more difficult to control for the vast majority of drivers. It cancels out the roll understeer feature of the original design making the car prone to sliding its tail out in corners instead of the front running out wider)
All have handled ok loaded or empty, all still under steer
 

muc the truck

Well-Known Member
I have been driving 4WD's for donkeys years and have plenty of mates that have also , all of em have had aftermarket suspension a few have had AirBags and yeah many have been over GVM , just about everyone I know has changed their suspension ,
To make this claim , I think is just bull .
( Lifting a heavily loaded rear end back up again is the exact opposite to what the car manufacturer intended and will make the car more difficult to control for the vast majority of drivers. It cancels out the roll understeer feature of the original design making the car prone to sliding its tail out in corners instead of the front running out wider)
All have handled ok loaded or empty, all still under steer
I have driven lots of different cars truck's and 4x4 (customers vehicles and boss owned toys ) almost all have after market suspension and non had oversteer except one with a Detroit rear locker as factory fitment GTHO not many off us run 4x4 with Detroit lockers . what he doesn't seem to recognise is any truck with air bags just keeps increasing air to the air bags until the level rod shuts the air supply off either with mechanical valves or electric no mater what the load it drives at the same height laden or empty and that doesn't affect . The Rear end is not sliding out on them when over loaded . My local bursons delivers 1000ltr oil crates one and a time with air bag helpers to stop the body roll . I don't see its rear end sliding out anytime soon . It would tip over from body roll before it did . I would like to hear from the guy that fitted 4 air bags in his cruiser a while back for his feedback . I cant remember who it was.
 
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2luxes

Well-Known Member
To make this claim , I think is just bull .
( Lifting a heavily loaded rear end back up again is the exact opposite to what the car manufacturer intended and will make the car more difficult to control for the vast majority of drivers. It cancels out the roll understeer feature of the original design making the car prone to sliding its tail out in corners instead of the front running out wider)
All have handled ok loaded or empty, all still under steer

The extract below is from this link. https://eprints.usq.edu.au/3971/1/Parkin_2007.pdf
....................................................................................
57 Essentially the axle roll is relative to that of the chassis, the wheels travel in a path that is right angled to the roll axis. With roll understeer the wheel going into bump moves forward and the wheel drooping moves rearward, effectively when the vehicle rolls left it steers left and roll over steer is the opposite of this. Due to the wheels being conjoined by what is in essence a rigid beam, the forward motion in bump and rearward motion in droop means that the whole axle is steering relative to the centreline of the chassis (Millekin, Millekin, 1995).
...........................................................................................

This is a brief explanation and involves a multi link design. Leaf springs do the same thing. The angle of the rear axle in relation to the centre line of the car is changed during corners and this is made possible by the length and angles of suspension links and the length and position of leaf springs. When a car is fully loaded, a leaf spring will be running up hill back to the axle or it will be until someone puts an air bag between the axle and chassis. This may not make a noticeable difference to handling in ordinary driving but it will in emergency situations and can easily make the difference between bringing the car back under control or loosing it.

I have posted this link before. It is on a different suspension design but covers rear wheel steering in corners. https://www.civilengineeringhandbook.tk/vehicle-technology/1082-suspension-roll-steer.html

Changing wheel angles in corners is not going to bend a chassis which is the subject of this discussion. Overloading or incorrect loading will and that has been my concern since I first became aware of it about ten years ago. Unfortunately it is going to continue as long as people put too much heavy material too far back behind the axle and are told in net forums and 4x4 expos that stock suspensions are crap and you need brand X springs or air bags to rectify the problem. The real solution is to move some items forward or take them out of the car.

When you load a car to the point where the rear end is sagging, you will be putting the chassis at risk. You can lift it with springs or bags then drive over tracks like the Canning or the Anne Beadell and come back saying the car was great and you had no trouble but you can't say for certain what is going to happen on future trips.
 

2luxes

Well-Known Member
Just as a follow up on the roll understeer feature of rear leaf spring suspensions, I found this post last night. The poster has been communicating recently with an American suspension engineer who works for one of the American car manufacturers. http://caravanersforum.com/viewtopic.php?f=2&t=75698&p=1120762#p1120762 Go down to the ninth post and read his second question and the answer that is highlighted in blue.

Look at the charts mixed in with these photos. https://www.google.com.au/search?q=...69u83ZAhUKwbwKHSxYDjUQsAQIKA&biw=1920&bih=974 Increasing the weight on the rear springs increases the chances of the car oversteering. The springs have been set up to counteract it and they are not going to be able to do that if the car is lifted back up by aftermarket parts when it is loaded and should be down.

Like it or not, that is the way cars have been designed for decades and maybe as far back as the new wave of cars that came onto the market a few years after WW2 ended. Rear spring geometry involving the front shackle down low and the rear up high so as to induce roll understeer in corners can be found in any suspension book no matter how basic.

Aftermarket spring or air bag manufacturers don't have to worry about this or tell buyers because it is not illegal to change a car's handling characteristics from the manufacturers built in understeer to oversteer. It is not very wise though if the car is in the hands of a driver who does not know how to handle oversteer in an emergency swerve or if the car goes into a corner a little too fast. The vast majority of drivers are in that category which is why all cars, except maybe special order Ferraris and the like, have been designed to understeer for as long as anyone can remember..
 

Swaggie

Moderator
Occasionally going down a very steep shaley, rocky track and alowing a touch more speed on original suspension that was basically clapped out the ass end would move out, quite liked the feeling to be honest but I kept it in check (never let it go too far) GOING slower it never happened...
 

2luxes

Well-Known Member
the ass end would move out, quite liked the feeling to be honest but I kept it in check (never let it go too far) GOING slower it never happened...

Oversteer can be fun providing you know what you are doing and are on closed circuit. It is never a good idea out on the highway. Unfortunately very few drivers can confidently control it, myself included.

The first answer from that American suspension engineer in that link that I posted is on "soft" spring bushes. A soft rubber front bush and hard rear changes the toe in in corners. All suspension engineers would know that but how many owners would?

He also mentions compliance steer. That is the suspension movement caused by the combined distortion in all the pivot points in the suspension both front and rear. Once again that is all taken into consideration when the suspension is being designed and tested.

The more you look into suspension design, the more complex it gets. There is a very good reason why today's cars handle infinitely better than they did even just a few decades ago yet they still look much the same when you look under them. If you are going to change the design of a suspension then at least find out how the thing works in the first place. Everyone knows what they are going to gain with their suspension mods but very few know what they have lost. It will always be a case of gain something loose something. Finding out what you have lost at cruising speeds on highways with plenty of cars around you is not the place to do it but that is where any losses will most likely show up.

There was a triple fatality involving a 4wd on the Gt Western Hwy in the lower Blue Mountains west of Sydney about two years ago. The car crossed the centre line on a left hand sweeping curve and into the path of an on coming car. The very extensive damage to the 4wd was all confined to the drivers side rear door and quarter panel. That car had oversteered and went sideways into the other car. I have no idea why it did it but that is one of the things that can happen when additional weight and stiffer suspension is placed at the rear of any car.

To make matters worse, we all use steel belted radial tyres these days. They tend to hang on then let go suddenly with little warning. The old cross plies where much more forgiving and gave you some warning. The only cross plies that you see these days are usually on cattle station utes in the Outback and that is for puncture resistance.
 

G_ute

Well-Known Member
Sorry to drag up an old topic but I wanted to know if anyone can advise the situation of airbags on coiled vehicles and the subsequent removal of the bumpstops, which I beleive may be illegal in some states.
I understand that the bumpstops play a vital role in protecting the chassis and warning the driver to take it easy if they are bottoming out.
Perhaps hitting the bumpstops also indicate the shocks may need to be upgraded.

I was reading up on these air-adjustable shock absorbers, which they claim is a load leveling device.
http://www.monroe.com/en-US/products/Max-Air/shock-Absorbers
Seemingly a USA-only thing, strangely.

These "Sumosprings Lite" also seem like a very quick and easy solution, anyone with experience of them?


I want to get may tray level with the slideon camper fitted and stay level when its not.

thanks.
 

peterfermtech

Well-Known Member
Had the Monroe air bags on my old Holden HT and thought they were great but back then any modification to the suspension was generally positive. I still think they would be great to try on a dual cab.
Have air bags in my MUX. They don't lift but add to the springs compression so help handle loads better.
 

mauriceb

Well-Known Member
Back in the late 70's i used similar coil wedges on the front of my HT Holden ute. They were to help stand up old sagged coils .The centre of the wedge was conical and sat there without moving . Maybe increase your coil ratings look at the specs in Force lb/in . With Kg load ratings i found each manufacturer can have different load rating compared to another on the same lb/in rated coil.
 
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