Thread: air suspension question

Coilers are slightly higher than the air suspension in normal height and lower than off road height.
Go for the air suspension as it is better generally off road and the handling and comfort so much better. Only in some situatios is it better.
Some have fitted longer springs on the coilers but it is not that much higher, I am sure some will give you a better idea.

In the dune example though I would think off road vs normal height would generally be an issue. Wouldn't the D3 have more than enough clearance for sand/dunes at normal road height?

From what I've seen, D3s don't need any run-up to get over dunes. I watched one do a standing start from the base of Big Red and fly over the top, once sand mode and DSC off were set at the same time.

Originally Posted by Ashes

In the dune example though I would think off road vs normal height would generally be an issue. Wouldn't the D3 have more than enough clearance for sand/dunes at normal road height?

has anyone got the under vehicle measurements for each height setting.

I know the trails around here as well as the inland tracks on Fraser have some decent size wheel ruts....and thats only a few places I have been

The air suspension is only too low where higher speeds are needed for momentum or where distances to be covered on deeply rutted tracks are too great to be done at 40-45kph (with the vehicle bonging at you, otherwise you need to keep it below 40kph).
At off road height as said is higher than coilers (and most other 4x4s) at speeds below the 50kph.
Also with the air the springs are cross linked and imitate the wheel travel of a fixed axle.

G/day 2 Door

If you check back to page 5 you will find some heights under the thread "How high is your D3"

I have the D3s tdv6 coiler and for me it does every thing I require of it now that it has had an after market lift (240mm clearence now. 185mm before). I wouldnt question the ability of the air suspension D3 and accept it has bells and whistles and credentials off road that the coiler hasn't got and could not match in some areas, but the improvement gained in the lift has taken it from very ordinary to more than acceptable and it is now a very competent off roader.

Sand driving before the lift was pretty hopeless, 185mm of clearence saw the D3 pushing sand and grading the tracks much to the pleasure of following drivers. The positives for me are,

The vehicle stays at 240mm regardless of speed. I personaly don't need TR for sand driving or any other form of driving for that matter. After 40 years of 4x4 driving both for leasure and occupation I still rather and can without TR make most of the terrain choices manually closely matching the Air D3, apart from heights and throttle response. But as I said before that suits the conditions that my vehicle is used for and my needs.

Sand I turn off DSC and I make the choice of what range/Hi/Low/auto or manual select the gear for the given conditions. Appropriate tyre pressures and gear choice selections also apply to other conditions. The point I am making is they are all available even without TR. Rock crawl! well I don't have TR to change the throttle response but Low range, first gear and steady as she goes gets me places that some people wouldnt even attempt. I still have hill decent and the traction control works just the same when I lift a wheel.

Other things! well the plough is no longer an issue (again for me) the tow ball is now the perfect hight for the boat trailer and I carn't see any issue for the future caravan at this point.

I don't have to worry about suspension pump failure. Don't need access height as we are all tall. Wheel alignments are more straight forward, gee what else? ah the ride, well it was pretty darn good before but it has also improved but I will not draw any comparison to the air as it is a while since I last drove one. The D3 coiler ride is streets ahead of anything else apart from the D3 air and the quiet smooth ride is the first thing people comment on when traveling with me.

Conclusion? well given the chance! I would probably have an air suspension D3 tomorrow, but then for my needs I would be faced with different issues for my circumstances.

Am I happy with what I have. Yes! but then each to his own opinion and view and D3 air suspension owners will be able to point out the good and the bad points for them

Cheers

wardh


Good write up of your experience.

I run training courses for D3 owners over here in the West, so I've both driven and visually compared both coilers (std and lifted) and air D3's over the same obstacles.

In sand, there is little difference between the lifted coiler and the EAS vehicles, although as you can't turn the traction control off in a coiler, it can kick in when you don't want it. Another exception is when you're bogged. The ability of the EAS to be raised and the traction control to be aggressively set will get you out where the coiler won't. On the other hand, the coiler won't lower itself at speeds above 50kph. For EAS vehicles, fitting shortened height sensor rods can overcome this problem.

In muddy terrain, or rock climbing, the EAS does everything easier, and in extreme conditions it'll pull through where the coiler won't. Two reasons for this - firstly, as CaverD3 mentioned, the EAS models are designed to mimic a live axle car when in low range. This gives you a lot more wheel articulation than any independently sprung coiler can achieve. Secondly the TR programs can vary the sensitivity of the traction control, so for instance in "rock crawl', you have virtually instant suppression of wheel spin. The traction control in the coiler is set to approximately that of the 'mud/ruts' TR setting in an EAS car.

Towing and heavy haulage is an area where the EAS cars really shine, due to the self-levelling. The coiler is still competent, but will obviously sag more than the EAS car.

Reliability vs complexity would at first sight favour the coiler, but in all the trips we've done, with 5 ~ 7 D3's on each, we've never had an EAS failure. In extreme conditions (competition, mud drags etc) I've only seen direct air failures related to physically hitting the compressor on rocks etc (we make a protection plate for this). There are unrelated errors that can cause the car to lower (wheel speed sensors, height sensors, EPB module failure), but it is possible to overcome most of these with some basic spares or splicing directly into the air lines and using an external compressor.

Note too that in a lifted coiler, you are running permanently at 240+mm. This _will_ prematurely wear the CV joints, and increases your fuel consumption by a noticible amount.

Hope this helps,

Gordon