AIR SUSPENSION
HAS ANY ONE FITTED OR KNOW ANYONE WHO HAS FITTED THIS UPGRADE TO THERE G
LOOKS GOOD BUT THEN ALL SALES TALK MAKES THINGS SOUND GOOD??????????
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1022342 |
Complete air suspension Mercedes G, all models |
I see no benefits.. had them on our vans..gave either a washy ride or hard...bags burst..much more to go wrong
The main advantage with air suspension for off roading is that you can adjust the ride height for much better clearance.You do not have to have a compromise between poor road handling or not enough off road clearance.
The kevlar air bags coming form the states are virtually un-burstable even in very extreme conditions. If you want your vehicle to be a competent off roader and be well mannered on the road adjustable air suspension is a very good way to achieve this.
A bonus of air suspension is that you have an onboard air compressor which comes in very useful.
Price of this kit?
I think you are right to be cautious as attempts to improve the Gs handling seems to follow the pattern: initial enthusiasm > implementation > silence. The G is 35 years old, no significant handling improvement can be achieved without reducing the high unsprung mass of the design (and weight of the Hutchinson wheels does not help in this context). An air suspension makes most sense if it is an active system, i.e. it continuously adapts its settings depending on driving conditions but even such a system would be handicapped by the high unsprung mass i.e. the air suspension reacts fast but the high unsprung mass results still in a slow reaction, in other words still a bumpy ride.
My only experience of air suspension was at the back end of a Disco 3/Td5 with active anti roll bars; this excludes a lot a Citreons owned which are strictly hydro-pneumatic but use an air bag as a spring.
My other experience is using it in industrial machines.
Mostly a hateful thing if used to replace steel springs; The spring rate of air bags is very low (i.e. steel is 100-200 lbs/in, air is typically 20-30 lbs/in). This translates into very poor roll resistance both across slopes and in corners. It is true a G has stiff suspension and hence diff locks .. but it means good road manners. No active air system could keep up with roads/bumps in corners.. hence the active anti roll bars are used in an attempt to improve things. It might be good as a load adjuster in addition to steel springs if you have varying payloads.
In a straight line and on rutted tracks (but not cross slopes), air suspension can work well as it allows a soft ride and allows the suspension to move/float to gain traction. Heavy live axles will slow it and suspect you will not get meaningful air flow in an active system without huge and impracticable pipes and tanks (see the 6x6 G and it huge tanks just for air in the tyres inflation systems) i.e. the air volume will stay with that which is inside the air bag for the time a "bump" is encountered.
That Td5 was hateful on a small narrow bumpy road as the back axle lost connection to the chassis and you had to guess where it was going to land/point the front the next time it got a meaningful connection. The active anti-roll bar just was not quick enough. The G on that road is a relative delight and when G's first came out I would run circles around coil sprung RR and it jumps well :-) I presume RR have worked hard on their systems, added independent suspension to reduce unsprung weight and managed to make a good solution with active anti roll bars.
Actually the best solution is hydropneumatic suspension ala Citreon/Jag/Merc/Rolls Royce .. but it takes a fair bit more to engineer .. add to that the active system from an Activa Xantia which switched accumulators/springs in/out on axles and anti roll bars and you would really have something.. hard when you need it, soft when you need it .. it would cost a fortune and mechanics would run a mile! Lotus did a proper active system over 20 years ago but needed about 25 hp just to run the pump!
So I guess the question would be what are you trying to achieve? Smooth road/track ride with better traction .. yes but IMHO the complexity and the compromises on corners/slopes would not be worth it ... unless you have active anti roll bars.. but that is more complexity!
thanks guys for your comments now i am confused by science
i was sort of thinking that the self leveling bit would sort out the
slopes uneven ground roll ect
i think the best idea is to stop off at ORC
and drive a G with it fitted to make a informed decision
adrian
that is the only way to find out; take the car to an empty parking lot, drive a sharp S (as if approaching a roundabout), the load change is the ultimate test of the system; in a 463 with ESP you should be able to do this at 40mph but be initially careful if the system is underdeveloped the car will have a tendency to overturn; and please tell us of the result as there is suspiciously little feedback on "improved" G suspensions like the Brabus system.
I gotta be honest here Adrian !
A "G's" a "G"
If you want air suspension (a very good one and with all the baubels)
Buy one of these =
TATA TRUCK Mmmmmmmmmmmmmmmmmm
I knew you'd like it !
We have a Mercedes ML amongst our stable of vehicles; it has air suspension (an option on the ML). Obviously the system you're looking at for the G will be different but I have to say that I think it's great and much better than the steel sprung ML. It provides for different ride heights and also 'comfort' or 'sport' settings. Road holding and handling are good and the ability to increase the ride height for off road use or (very useful here in northern Scotland....) dealing with snow is also good. Ride is very comfortable but I think that the 'sport' mode is a waste of time - maybe ok on really smooth tarmac but is very jittery and doesn't handle as well on our rough roads.
Hope this doesn't add to the confusion Adrian....... As has been said, I agree that you need to try the air equipped G in Austria and see what you think.
I seriously doubt if this system would improve the G in anyway and in all likelihood make it a pig. As per MGrays one of the nastiest vehicles I've ever had the misfortune to drive was a D2 with air suspension. A G is remarkable similar in it's suspension configuration with solid axles that weigh as much as a small car.
Porsche, VW, Audi, MB and LR all source the same systems. Ever wondered why there is are so many steel spring conversions for early RR's and Discoveries?
Audi, LR and MB for some reason (although they are the same manufacturer as the rest) have horrific and expensive reliability issues.
Newer RR's and D3/4's etc drive great but they have far more advanced suspension and associated electronic management and were designed from day one with active suspension in mind.
A G is a 30yr+ design, it is what it is and will never be a silk purse.
WE ALL SEEM TO BE SPLIT ON THIS
JUST CHECKED OUT GOOGLE MAPS
ORC Off Road Center GmbH
Uhlandstr. 91-93
73760 Ostfildern/ Germany
IS HALF WAY TO GRAZ THE PERFECT STOP OVER FOR ME IN AUG
SO I WILL CONTACT ORC AND SEE IF ITS POSSIBLE FOR ME TO TEST
CHECK OUT THIS SYSTEM
NOT SURE (OEM) MANUFACTURERS ONLY USE THE
BEST STUFF
THE BEAN COUNTERS PUT PAY TO THAT
ALSO I KNOW STEYR/PUCH HAVE A CLOSE WORKING RELATIONSHIP WITH ORC
SO WILL ASK THERE OPINION WHEN I MEET UP WITH THEM
If you have a technical head on ... then go look at the spreadsheet linked to in this post;
http://neuralfibre.com/paul/4wd/airspring-airbag-suspension-calculator
See the third tab over.. the one called "Polyair charts". The load/weight is on the vertical/Y axis and stroke/compression on the horizontal/X axis. Note the lines are very very flat i.e. look at the yellow line (15 psi?) and 500kg load.. you can go from fully extended to fully compressed by adding 200kg and this is over a 560mm/20" stroke .. so 440lbs/20" = 22 lbs/in !!! A typical G spring rate is 476 lbs/in. Compare those lines to the air+steel curves on "polyair+spring" and you can see dramatically stiffer springs because they are adding air to exisiting steel springs (in place of bump stops) to get better heavy load rides.
The spring rates of air bags change and so are progressive .. but so are the G springs. You also tweak air bags by fitting larger (hence lower air pressure) ones to get a low spring rate and plush ride ... or smaller ones (higher air pressure and hence stiffer) . Also the side walls are thicker on some so you effectively partially ride on the side walls.. which is another variable.
Self levelling will keep it level but it is what happens when you load a corner/wheel.. with soft spring rates the wheel moves easily = soft ride/good traction.. but if you are moving it due to side slopes or corners.. then it lurches like your best yank tank car.. or Rolls Royce before they took out a license from Citreon :-) .. Anyway a drive will tell you what if you like it.
The main advantage with air suspension for off roading is that you can adjust the ride height for much better clearance.You do not have to have a compromise between poor road handling or not enough off road clearance.
The kevlar air bags coming form the states are virtually un-burstable even in very extreme conditions. If you want your vehicle to be a competent off roader and be well mannered on the road adjustable air suspension is a very good way to achieve this.
A bonus of air suspension is that you have an onboard air compressor which comes in very useful.
ian its not the axles that are the problem with a LWB its the under belly
one of the reasons I prefer the SWB.
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Who's new
- Jaffa_JIM_23
- Wrabstar
- GG
- KTMSCANIA22
- 280ge
sport-mode: From a speed more than 100 km/h the suspension lower the car automatically ca. 20 mm, so you get a better road handling and save fuel. If you drive less than 100 km/h (for more than 70 sec.) the suspension higher the car automatically back to standard height.
parking-mode: The suspension can be lowered max. ca. 55 mm for parking in a garage, for better loading and also for much more comfortable get in and out of the car.
In this position the maximum speed is 25 km/h. If you drive faster, the suspension higher the car automatically to the standard height.
off-road-mode: In this mode the suspension can higher the car ca. 25-50 mm to get more ground clearance on bad roads.
In this height the max.speed is 40 km/h. If you drive faster, the suspension automatically lower the car to standard height.
AutoLevelModule – electronic air level (optional): Herewith you can bring the car to horizontal at uneven underground.
Price complete air suspension 5.111,05 Euro, emergency valve set for filling of the air bellows (with an external compressor, absolutely recommended) 178,50 Euro (plus mounting costs). Optional Auto-Level-Module
MYSELF i quite like the idea of this setup but as i have just got the ORC + 40MM springs & shocks
i need to try this out first if i don't like it i will BAG the G
my only concern is the sport mode NOT SURE the mighty 617a can maintain a high enough speed
and it may end up be like driving a JACK IN THE BOX
I AM going to GRAZ in aug for some offroad FUN to try out my new setup so i might stop of at ORC and see if the sport mode can be
re-set at a more realistic speed
ADRIAN