Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Albatross on 24 April 2008, 21:22:37

Title: How does it know?
Post by: Albatross on 24 April 2008, 21:22:37
How does the self levelling suspension on the rear of an Elite facelift actually work?

I mean how does it know what level it is at and why doesn't it try to level itself out when going down or up a hill? :-/

Title: Re: How does it know?
Post by: Andy B on 24 April 2008, 21:51:47
Quote
How does the self levelling suspension on the rear of an Elite facelift actually work?

I mean how does it know what level it is at and why doesn't it try to level itself out when going down or up a hill? :-/

There's a level sensor on the rear OFF side trailing arm.
Title: Re: How does it know?
Post by: TheBoy on 24 April 2008, 21:52:42
If removing self levelling, pull fuse on it.
Title: Re: How does it know?
Post by: Albatross on 24 April 2008, 22:01:36
I'm not trying t remove it, I'm just technically interested in "how" it actually works. I mean what does it use to measure and to what point of reference?

It leads me back to the original question: Why doesn't it get its knickers in a twist about going up or down a slope?
Title: Re: How does it know?
Post by: TheBoy on 24 April 2008, 22:02:49
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I'm not trying t remove it, I'm just technically interested in "how" it actually works. I mean what does it use to measure and to what point of reference?

It leads me back to the original question: Why doesn't it get its knickers in a twist about going up or down a slope?
sensor osr arm, measures distance between suspension arm and chassis
Title: Re: How does it know?
Post by: Albatross on 24 April 2008, 22:04:48
Quote
Quote
How does the self levelling suspension on the rear of an Elite facelift actually work?

I mean how does it know what level it is at and why doesn't it try to level itself out when going down or up a hill? :-/

There's a level sensor on the rear OFF side trailing arm.

Yeah, bt is it measuring "level" with a fluid sensor? Surely this would get confused when the car was on a slope.

What is the point of reference; is it gravity or relative position to the rest of the car?
Title: Re: How does it know?
Post by: Andy B on 24 April 2008, 22:06:40
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.....
What is the point of reference; is it gravity or relative position to the rest of the car?


Quote
........
sensor osr arm, measures distance between suspension arm and chassis
Title: Re: How does it know?
Post by: Entwood on 24 April 2008, 22:07:20
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I'm not trying t remove it, I'm just technically interested in "how" it actually works. I mean what does it use to measure and to what point of reference?

It leads me back to the original question: Why doesn't it get its knickers in a twist about going up or down a slope?

It doesn't measure the "slope" of the car, it measures the distance of the suspension at the back, relative to the front, and makes them equal.

When you load the car, you compress the rear suspension relative to the front .. it pumps it back up to equal.
Title: Re: How does it know?
Post by: TheBoy on 24 April 2008, 22:16:00
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Quote
Quote
How does the self levelling suspension on the rear of an Elite facelift actually work?

I mean how does it know what level it is at and why doesn't it try to level itself out when going down or up a hill? :-/

There's a level sensor on the rear OFF side trailing arm.

Yeah, bt is it measuring "level" with a fluid sensor? Surely this would get confused when the car was on a slope.

What is the point of reference; is it gravity or relative position to the rest of the car?
I simply measures the distance between the distance between the suspension arm and the chassis, same way the HID level sensors do.  Look at sensor, it will make perfect sense.
Title: Re: How does it know?
Post by: Albatross on 24 April 2008, 22:26:56
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Quote
.....
What is the point of reference; is it gravity or relative position to the rest of the car?


Quote
........
sensor osr arm, measures distance between suspension arm and chassis


Yeah, thanks I saw that, my t'tinterweb connection is playing up >:( so our posts crossed in the disconnect delay
Title: Re: How does it know?
Post by: Albatross on 24 April 2008, 22:32:18
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Quote
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How does the self levelling suspension on the rear of an Elite facelift actually work?

I mean how does it know what level it is at and why doesn't it try to level itself out when going down or up a hill? :-/

There's a level sensor on the rear OFF side trailing arm.

Yeah, bt is it measuring "level" with a fluid sensor? Surely this would get confused when the car was on a slope.

What is the point of reference; is it gravity or relative position to the rest of the car?
I simply measures the distance between the distance between the suspension arm and the chassis, same way the HID level sensors do.  Look at sensor, it will make perfect sense.

I wonder if it can "adjusted" or tricked by a cm or so.
Title: Re: How does it know?
Post by: VXL V6 on 24 April 2008, 22:34:36
It won't lower your car, it simply aims to level out the back if it's loaded up and the rear is compressing the springs / shocks.

Title: Re: How does it know?
Post by: hotel21 on 24 April 2008, 22:36:01
The length of the adjuster rod can be extended or shortened, as I recall, in the same way as those for the self levelling HID motors.
Title: Re: How does it know?
Post by: TheBoy on 24 April 2008, 22:40:24
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It won't lower your car, it simply aims to level out the back if it's loaded up and the rear is compressing the springs / shocks.

correct.
Title: Re: How does it know?
Post by: Albatross on 24 April 2008, 22:43:48
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It won't lower your car, it simply aims to level out the back if it's loaded up and the rear is compressing the springs / shocks.


If the sensor beleves that "level" is lower because it is sensing something different then I might be inclined to disagree.

Reading H21's post ^ I'd say it might be possible. It is just a case of understanding how the sensor works and is built before knowing.

I don't want to go mad, but if you look at the picture below you'll see why I'm asking...

(http://farm3.static.flickr.com/2302/2439744782_8f9bc9074f.jpg)


Title: Re: How does it know?
Post by: TheBoy on 24 April 2008, 22:46:48
pull off the airlines, and see if it lowers.
Title: Re: How does it know?
Post by: VXL V6 on 24 April 2008, 22:48:16
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Quote
It won't lower your car, it simply aims to level out the back if it's loaded up and the rear is compressing the springs / shocks.


If the sensor beleves that "level" is lower because it is sensing something different then I might be inclined to disagree.

Reading H21's post ^ I'd say it might be possible. It is just a case of understanding how the sensor works and is built before knowing.

I don't want to go mad, but if you look at the picture below you'll see why I'm asking...

(http://farm3.static.flickr.com/2302/2439744782_8f9bc9074f.jpg)



It can't pull the back down IMHO, it does the opposite, it lifts the back up when loaded.

I can see what your concern is from the picture though. Perhaps a chat with Tony at WIM would be a good idea......
Title: Re: How does it know?
Post by: Albatross on 24 April 2008, 22:50:28
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pull off the airlines, and see if it lowers.

? - how do I do that? Is that safe?

Am I wrong, is the angle of the car in my picture normal/correct?

I don't really want to lose the self levelling, but I think it just looks wrong. That picture is the worst angle mind you.

Here's another taken at the same time earlier today from a slightly different angle.

(http://farm3.static.flickr.com/2272/2439548558_d851099480.jpg)
Title: Re: How does it know?
Post by: TheBoy on 24 April 2008, 22:51:45
Hard to tell from picture, but sill should be roughly level, if that helps
Title: Re: How does it know?
Post by: Entwood on 24 April 2008, 22:52:50
Measure the wheel arch to top of wheel front and back .. should be about the same ...

Its possible yours is stuck in the fully up position - I guess which is why TheBoy says to disconnect the line and see if it drops ....
Title: Re: How does it know?
Post by: Albatross on 24 April 2008, 22:57:24
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Hard to tell from picture, but sill should be roughly level, if that helps

What about this picture?

(http://farm3.static.flickr.com/2075/2439768956_85dd5c0862.jpg)
Title: Re: How does it know?
Post by: Andy B on 24 April 2008, 22:57:45
Mine's a prefacelift car but I've just measured mine from the floor to the bottom of my wheel arch .....  26.5"
Title: Re: How does it know?
Post by: Albatross on 24 April 2008, 23:03:13
I've just popped out and, bearing in mind it is dark; from the floor to the top of the rear wheel arch is 27".

The gap between the top of the rear wheel and the arch is 3", on the front it is 2"
Title: Re: How does it know?
Post by: VXL V6 on 24 April 2008, 23:05:04
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I've just popped out and, bearing in mind it is dark; from the floor to the top of the rear wheel arch is 27".

The gap between the top of the rear wheel and the arch is 3", on the front it is 2"

Try measuring the height of the sill at the front and rear. The wheel arches are different sizes front / rear (front wheel turns!)
Title: Re: How does it know?
Post by: Debs. on 24 April 2008, 23:05:13
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Hard to tell from picture, but sill should be roughly level, if that helps

What about this picture?

(http://farm3.static.flickr.com/2075/2439768956_85dd5c0862.jpg)

Gosh!...
I wish my Miggy sat that high Albatross: mine skulks along and due to the deeply rutted state of my farm`s driveway, I fear it wont be too long before some vital bits are torn off the car`s undercarriage.
The sump plug seems favourite ATM as it leaves a grove in the central ground-ridge for many tens of metres.  :'(
Title: Re: How does it know?
Post by: Albatross on 24 April 2008, 23:14:41
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I've just popped out and, bearing in mind it is dark; from the floor to the top of the rear wheel arch is 27".

The gap between the top of the rear wheel and the arch is 3", on the front it is 2"

Try measuring the height of the sill at the front and rear. The wheel arches are different sizes front / rear (front wheel turns!)

I understand that the wheel arches are different heights, but I was giving measurements as a comparison with other people's cars.

Sill height behind front arch is 6.5" and just in front of the rear arch is about 7.5" :-/
Title: Re: How does it know?
Post by: VXL V6 on 24 April 2008, 23:16:59
Looking at the picture again I think there's also a bit of an optical illusion going on.... The tyres have so little sidewall compared to standard 235/45/17's that it exagerates the gap even more.

As I said earlier, a chat with Tony at WIM would be a good idea.
Title: Re: How does it know?
Post by: hotel21 on 24 April 2008, 23:19:45
The first pic certainly looks high, to my eye at least.

If there is a fault with the elctrical connection to the sender on the suspension the system defaults to max height, rather than min height, if you follow.

Not sure which fuse powers the compressor (check the FAQ/Tech info sections) as pulling same should stop the compressor.

Or pull the airline off the top of the shocker (carefully, so as not to get squished) and it should lower....

Or unbolt the sender and play with it.  Car should raise/lower if all working OK....
Title: Re: How does it know?
Post by: Albatross on 24 April 2008, 23:20:16
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Looking at the picture again I think there's also a bit of an optical illusion going on.... The tyres have so little sidewall compared to standard 235/45/17's that it exagerates the gap even more.

As I said earlier, a chat with Tony at WIM would be a good idea.

I'm booked in at WIM on Saturday 17th of May (I was talking to him earlier today, but didn't discuss this issue), but that is to get the car's tracking checked etc. I'm afraid that if there's something wrong here that the visit to him will be wasted because the car should be set at the right height before he adjusts it.

Do you reckon he'll be able to advise in advance over the phone?
Title: Re: How does it know?
Post by: Andy B on 24 April 2008, 23:22:15
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............

Not sure which fuse powers the compressor (check the FAQ/Tech info sections) as pulling same should stop the compressor.....

fuse 27
Title: Re: How does it know?
Post by: VXL V6 on 24 April 2008, 23:22:55
If it helps I'll check the ride height (at the sills) and to the top of the front and rear arches on mine, should give you roughly the correct heights for the identical model of Omega then.

NB. My car is on original shocks / springs etc and has covered 68K.

Title: Re: How does it know?
Post by: Albatross on 24 April 2008, 23:23:41
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Quote
............

Not sure which fuse powers the compressor (check the FAQ/Tech info sections) as pulling same should stop the compressor.....

fuse 27

Are they obviously numbered?  Are they under the steering wheel?
Title: Re: How does it know?
Post by: hotel21 on 24 April 2008, 23:25:18
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Quote
Quote
............

Not sure which fuse powers the compressor (check the FAQ/Tech info sections) as pulling same should stop the compressor.....

fuse 27

Are they obviously numbered?  Are they under the steering wheel?

yes and yes....

or check your handbook, if you have one, or the FAQ if not....   ;)
Title: Re: How does it know?
Post by: Albatross on 24 April 2008, 23:25:46
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If it helps I'll check the ride height (at the sills) and to the top of the front and rear arches on mine, should give you roughly the correct heights for the identical model of Omega then.

NB. My car is on original shocks / springs etc and has covered 68K.

 

Excellent thanks, mine's original too and has done about 90k now, so should be lower if anything given the greater mileage.
Title: Re: How does it know?
Post by: VXL V6 on 24 April 2008, 23:29:28
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Looking at the picture again I think there's also a bit of an optical illusion going on.... The tyres have so little sidewall compared to standard 235/45/17's that it exagerates the gap even more.

As I said earlier, a chat with Tony at WIM would be a good idea.

I'm booked in at WIM on Saturday 17th of May (I was talking to him earlier today, but didn't discuss this issue), but that is to get the car's tracking checked etc. I'm afraid that if there's something wrong here that the visit to him will be wasted because the car should be set at the right height before he adjusts it.

Do you reckon he'll be able to advise in advance over the phone?

Send him a message on the WIM forum.
Well worth getting the Geo done regardless as he can highlight any issues for you. He will also work out the ideal settings for cars with modified suspension / non-standard wheels.
Do make sure you have a full tank of fuel when you get to the centre though as all calculations are performed with the tank full.

He is going to fit two new wishbones to mine (far less hassle for me!!!!)and redo the Geo for free, Top Man!
Title: Re: How does it know?
Post by: VXL V6 on 24 April 2008, 23:32:04
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Quote
If it helps I'll check the ride height (at the sills) and to the top of the front and rear arches on mine, should give you roughly the correct heights for the identical model of Omega then.

NB. My car is on original shocks / springs etc and has covered 68K.

 

Excellent thanks, mine's original too and has done about 90k now, so should be lower if anything given the greater mileage.

No problem, but will have to do it tomorrow when I get back from work now!  :y

Title: Re: How does it know?
Post by: Albatross on 24 April 2008, 23:37:55
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Quote
Quote
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............

Not sure which fuse powers the compressor (check the FAQ/Tech info sections) as pulling same should stop the compressor.....

fuse 27

Are they obviously numbered?  Are they under the steering wheel?

yes and yes....

or check your handbook, if you have one, or the FAQ if not....   ;)

Took out fuse 27. Ran the car for 5 minutes. Sat on the boot lip whilst it was running and bounced.

Stopped car.

Measured: no difference.

Replaced fuse.

Ran car and watched, heard compressor, but no ride height change.

(I did notice that fuses 4, 10 & 24 are not present though :-/)
Title: Re: How does it know?
Post by: VXL V6 on 24 April 2008, 23:39:44
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(I did notice that fuses 4, 10 & 24 are not present though :-/)

Pretty sure they are missing from mine as well, will have been for non-uk options etc.



Title: Re: How does it know?
Post by: Albatross on 25 April 2008, 00:23:47
As a comparison to the 3rd picture, the car from the original Autotrader pictures that I bought it based on, and from a similar OSR angle, the ride height at the rear hasn't changed much, if at all, as far as I can tell from then.

(http://farm3.static.flickr.com/2075/2439768956_85dd5c0862.jpg)
(http://farm3.static.flickr.com/2060/2439089005_15ec363897.jpg)
Title: Re: How does it know?
Post by: Danny on 25 April 2008, 00:47:22
i was gonna say that sometimes the sensor can be knocked if you're not careful when changing the wheels.... until i saw the photo of the standard one before the 19s went on it...
Title: Re: How does it know?
Post by: Albatross on 25 April 2008, 00:50:52
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i was gonna say that sometimes the sensor can be knocked if you're not careful when changing the wheels.... until i saw the photo of the standard one before the 19s went on it...

Unless someone did that before I bought it?

What do you think?

Here's a side view from when I bought it, if you look at the angles of the side of the land Rover behind it ou can see that the camera was on the p!ss when the picture was taken. Look how much lower the rear wheel is than the front too...

(http://farm3.static.flickr.com/2072/2238548775_1e4ac9a23c.jpg)
Title: Re: How does it know?
Post by: Danny on 25 April 2008, 00:54:58
wouldnt a faulty sensor push it right the way up though? yours doesnt look overly high, just slightly higher than it should be
Title: Re: How does it know?
Post by: Albatross on 25 April 2008, 00:57:27
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wouldnt a faulty sensor push it right the way up though? yours doesnt look overly high, just slightly higher than it should be

It still looks a lot higher than the rear end of the car in your pictures in your signature though
Title: Re: How does it know?
Post by: Danny on 25 April 2008, 01:07:39
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wouldnt a faulty sensor push it right the way up though? yours doesnt look overly high, just slightly higher than it should be

It still looks a lot higher than the rear end of the car in your pictures in your signature though

my shocks are leaking tho, both need replacing
Title: Re: How does it know?
Post by: Marks DTM Calib on 25 April 2008, 08:31:06
Pop the arm off the sensor and move it to check the back goes up and down .....
Title: Re: How does it know?
Post by: VXL V6 on 25 April 2008, 18:17:30
68K, Engine not running, 1/2 tank of fuel:-

Rear Wheel Arch - 67cm
Front Wheel Arch - 67cm
Rear Sill - 19cm
Front Sill - 17cm
Centre of wheel - 30cm

HTH
Title: Re: How does it know?
Post by: markey mark on 25 April 2008, 18:23:05
could it possibly have had the wrong springs fitted on the back nath ?? does look bloody high !! what size are your tyres on back ?? :(
Title: Re: How does it know?
Post by: Albatross on 25 April 2008, 22:29:24
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68K, Engine not running, 1/2 tank of fuel:-

Rear Wheel Arch - 67cm
Front Wheel Arch - 67cm
Rear Sill - 19cm
Front Sill - 17cm
Centre of wheel - 30cm

HTH

Mine is

Rear Wheel Arch - 67cm
Front Wheel Arch - 67cm
Rear Sill - 19cm
Front Sill - 17cm
Centre of wheel - 30cm

Exactly the same :-/


Quote
could it possibly have had the wrong springs fitted on the back nath ?? does look bloody high !! what size are your tyres on back ?? :(

Nope, and 235x35x19 which is the same rolling radius

I'm confused now. I'll try what MarksDTM suggested about the sensor tomorrow and report back
Title: Re: How does it know?
Post by: Albatross on 26 April 2008, 14:32:04
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Pop the arm off the sensor and move it to check the back goes up and down .....

What exactly, and where, am I looking for here?
Title: Re: How does it know?
Post by: hotel21 on 26 April 2008, 14:37:33
Rear offside suspension arm.

Towards the front 'hinge' section.

Plastic block with electrical connectors to it.  There is a small (2 inch or thereby) arm linking the block to the bodywork with balljoints at either end.

The balljoint can be carefully popped off and movement of the arm whould give movement of the suspension.

Had a look for a piccy but none to hand yet.  My car does not have self levelling so will see if I can find one somewheres on here....   :y
Title: Re: How does it know?
Post by: Albatross on 26 April 2008, 14:45:53
OK, found it and done that, thanks :y

I can make the car jack itself up by sliding the arm upward and then back down again to where it is (lowest point) by pulling the lever/arm back down again.

What do you reckon to lowering springs (maybe from a MV6) and then adjust (bend) the arm accordingly so that it is tricked into thinking the new ride height is where it should be?

Title: Re: How does it know?
Post by: hotel21 on 26 April 2008, 14:49:55
so....  where your car normally sits is at its lowest limit when you manually move the arm to its limit when disconnected?  If thats the case then it appears to be adjusted correctly?

If there is something out of sync then carefull adjustment should be in order.
Title: Re: How does it know?
Post by: Albatross on 26 April 2008, 14:55:26
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so....  where your car normally sits is at its lowest limit when you manually move the arm to its limit when disconnected?  If thats the case then it appears to be adjusted correctly?

If there is something out of sync then carefull adjustment should be in order.

I'd say it appears to be adjusted correctly, but my question was with a mind to trying to lower the rear end ever so slightly (maybe the 15mm that is the MV6 ride height?), but still retain the self levelling, to that level.


Do you see what I mean? Am I making sense?
Title: Re: How does it know?
Post by: Ian_D on 26 April 2008, 14:55:31
Not read all of the thread, but on mine, the rod is disconnected (long story.. I got stuck in mud - car bottomed out, so I unclipped it to make the suspension rise the car!), and its now left in its lowest position (need to clip it back on one day)

All I can say, is that is WAY off full hight! I will take a pic of mine sometime, as I can manually controll it now  ;D

Trust me... The Omega looks like its a monster truck in the making when its at full hight (the gap between wheel + arch is a good few inches) ;)
Title: Re: How does it know?
Post by: Albatross on 26 April 2008, 23:55:03
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so....  where your car normally sits is at its lowest limit when you manually move the arm to its limit when disconnected?  If thats the case then it appears to be adjusted correctly?

If there is something out of sync then carefull adjustment should be in order.

I'd say it appears to be adjusted correctly, but my question was with a mind to trying to lower the rear end ever so slightly (maybe the 15mm that is the MV6 ride height?), but still retain the self levelling, to that level.


Do you see what I mean? Am I making sense?


Do you see what I mean? Am I making sense?
Title: Re: How does it know?
Post by: Albatross on 27 April 2008, 14:49:11
I'd say the self adjustment and current ride height appears to be adjusted correctly, but my question was with a mind to trying to lower the rear end ever so slightly (maybe the 15mm as that is the MV6 ride height?), but still retain the self levelling, to that level.

I'm wondering whether fitting MV6 springs all round and then slightly shortening the length (carefully and under a watchful and knowing eye) of the self-level sensor arm to suit would then allow me to lower the car to MV6 height and retain the self levelling.


Do you see what I mean? Am I making sense?
Title: Re: How does it know?
Post by: hotel21 on 27 April 2008, 18:53:01
Quote
I'd say the self adjustment and current ride height appears to be adjusted correctly, but my question was with a mind to trying to lower the rear end ever so slightly (maybe the 15mm as that is the MV6 ride height?), but still retain the self levelling, to that level.

I'm wondering whether fitting MV6 springs all round and then slightly shortening the length (carefully and under a watchful and knowing eye) of the self-level sensor arm to suit would then allow me to lower the car to MV6 height and retain the self levelling.


Do you see what I mean? Am I making sense?

yes.   :y

Title: Re: How does it know?
Post by: TheBoy on 27 April 2008, 19:51:42
I wouldn't. If you want it lower/stiffer, put sports suspension on, junk the self levelling.  If you want self levelling, keep the elite setup.  Mismatching shocks and springs may lead to unpredicatable handling.