EAS P38 Lift Using Recalibration
Hardy Neale's Approach
Early Experiments with Recalibration
Final "Stage II" EAS System
Chris Compton's Experience
Musings on Alternative Approaches
Hardy Neale has pioneered another method of lifting the air suspension -- using recalibration of height settings. He was the first to try a method of getting more lift out of air suspension models that is purely electronic -- you can change the default height settings in the air suspension's ECU using the TestBook or the aftermarket equivalents now available at much lower cost.
at right: Hardy's 4.0 with 265/75R16
tires and recalibration lift
in High Profile mode)
Early Experimentation with Electronic Recalibration Method
Hardy reported in 2003 that some time ago he read with great interest the article on Rangeroves.net on extended profile selection & re-calibrating the height settings. He had since had the height settings on his '99 4.0 EAS re-set by Rick's 4WD as follows:
Freeway - default
Standard - 15mm higher (room for Cooper ST 255/70 x 16 tyres)
High - 30mm higher, the full whack - emulates emergency extended setting.
Extended - default
The procedure did not even involve setting blocks under axles etc -- Hardy's mechanic simply plugged his computer (Autologic, not LR testbook) in and increased existing settings by above values in 5 minutes with the car parked in the driveway. "Each airbag has a specified setting for the different heights; I just asked Rick to increase the existing values by 15 and 25 mm."
Hardy reports having no troubles since -- and this method does bypass the problem with the EAS bypass circuit I developed in that you cannot accidentally go higher than the standard "Extended" mode and run the risk of popping the bags. Hardy reports his friends are rather impressed with his extra lift selectable at the press of a button -- his "high" mode is over 2.5 inches above the default "standard" setting.
At these extreme height settings, ride quality and articulation do deteriorate noticeably, so the particular tradeoff you use is up to you. As always, use at your own risk!!
Chris Crompton's Experience
Chris Crompton of the UAE found in January '04 that his dealer could not do this procedure with the standard Testbook, so it may be necessary in that case to "fool" the Testbook during the calibration procedure by adding a shim to each of the blocks used between the axle and chassis to calibrate the height.
"Stage II" EAS Modifications
As noted above, Hardy initially got his mechanic to dial in a lift in the normal and off road settings of his RR. After trying this for a while, he experimented with putting the bags from the longer rear springs on the front to allow higher settings (see photo below).
Rear spring bellows with its longer bottom piston fitted to front axle. Note this shot is at maximum ride height, but there is still some travel left in the air spring.
For the rear, Hardy found that new aftermarket rear bellows were longer than OEM (see pictures on Air Spring Bellows Replacement Page) so he used these. Testing the articulation without the rear shocks connected he found he could get about another 2 inches at the shock mounts. However his search for longer shocks proved fruitless so for now he left the stock rear shocks in place. In the new higher settings he chose (see below) this only allows a couple of inches of axle droop, a problem that may be addressed later. Meanwhile Hardy notes "I've heard some concern over standard airsprings ripping off mounts when vehicle is jacked by chassis instead of axle.On my vehicle (std shockies and longer springs) this cannot happen."
He also considered lifting the rear further using spacers, and even made some up. However in the absence of a solution to the shock problem, this aspect was put on hold.
Meanwhile, Hardy replaced the 255//70 tires he had been using with 265/75s, and had new lower ratio 4.1 ring and pinion gears from Great Basin Rovers installed to compensate for the larger tire size (see page on air supply for locker and tire inflation). With the new longer springs front and rear, Hardy was able to get the EAS reprogrammed again to higher settings commensurate with the new tires and gears. The final settings were as follows:
Standard height is still 15mm higher than factory.
High Profile height is now
50mm higher than the new std height - that is it goes up another 2"
when the "High Profile" rocker switch is activated.
Hardy reports "So with new max height
setting combined with longer airsprings all round (old rears in front,
new longers in rear) and the new tires (Cooper
ST 265/75 tyres, no longer 255/70) the car
is quite well behaved and comfortable on bumps. There is still only about 2-3" travel droop
left at max height (thanks to use of standard shocks) so I still only
use this setting when I really have to. But when I do hit the
EAS off road button, I now have 4" of additional chassis clearance over
std RR at std height.
EAS plus extra 35mm from 265/75 tyres).
"The new larger tires fit beautifully, just rubbing slightly on the inside of front mudflaps while turning on driveway gutters etc. Freeway mode works fine too, just rubs a little more while turning on bumps (time to go up). The plan was to go with 255/85 but I chickened out, preferring to preserve the RR good manners somewhat.
"As it is now I reckon I have a pretty good set-up - compared with a bog stocker. With new tyres and 15mm EAS adjustment - the car sits over 2" higher in std mode (Fine for most trail work). When needed, the car can go up another 2" + while still maintaining a comfy ride (Over logs, water etc). But only leaves a couple inches of down travel thanks to std shock. See 4th pic - front axle max height setting. I don't know what would happen to OEM airsprings & shockers with all wheels in the air!!?? I'll address the down travel thing once I get tired of playing with my rear locker....." (See page on air supply for locker and tire inflation for more on Hardy's locker installation).
Musings on Remaining Problems and Alternative Approaches
During the process of
arriving at the final setup Hardy is now using (detailed above), Hardy
sent in the following reports about his thoughts on further
improvements to his EAS to gain more height and travel. These are
reprinted here in case other readers have ideas on how to solve the
"I'm having trouble finding longer travel shocks - required travel is quite specific, so it looks as though I have to make some extension brackets up instead. I have physically determined that I can achieve an extra 2" axle droop both front and back (2" at shock mounts - probably 3" at wheels) while still using original shocks. I prefer this option anyway as it's much cheaper.
"I may have to obtain sway bar disconnects s the sway bar does seem like it may hinder articulation by physically hitting the axle."
Part way through development of the Stage II system above, Hardy also considered lifting the rear further using spacers, and even made some up. "Below is a picture of 1" spacers I made for rear axle -- I had a mate use his plasma cutter for the cut out. I hadn't drilled mount holes as yet - still thinking..... The airspring and piston is ex front axle. I may end up using these spacers on the front. Dunno yet."
Spacers Hardy had made as one
method of gaining a lift (Photo shows spacer atttached to lower front
spring piston but original intention was to use it on the rear and gain
the front lift by using rear springs).
"Rovertym make a 2" spacer kit for SLS Discovery's. http://www.rovertym.com/slsspacers.htm. It confirmed I'm on the right track. They look 'canted' -- I thought of doing this too, but discounted it as it might cause problems under compression - mis-aligning the top of the piston out the edge of bag. I even tried to imagine some sort of hinged spacer to allow for the effect of the radius arm pulling rear of airspring away from piston. But I think a 'slinky spacer' would be the way to go. A hollow piston platform with an internal coil would allow the airspring and piston to pull away from axle under extreme droop, relying on the 'slinky spacer' spring to relocate.
"The next idea is to go back to basics. 2" spring spacers all round, reset the offroad height back down a bit. Increase bumpstops by 1" or 2", then I'll aim to increase axle droop front and rear using combination of correct length shock absorbers and my longer springs. I came across this idea while trying to fit front shocks onto rear - they really have a bit too much travel for the one inch spring spacers. I have to recheck their possible fitment too - if they work.... give rear axle 5" more down travel - less 2" for compressed size / bumpstops.... they'll be one cheap & easy performance enhancement!"
Like many of our Rovers, Hardy's RR is a work in progress, and these ideas may serve as fodder for someone else's efforts.