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Discussion Starter · #1 ·
Hi,

The previous owner of my 3.8 M5 decided to replace all EDC dampers with regular BMW ones for the 535i, when one of the EDC's started leaking. I'm OK with this tradeoff since the handling is more than enough for my driving style anyway. However, the rear end is lowered compared to a stock M5, ie the 235/45-17" wheels are slightly covered by the wheel arches. (Looks like the front ride height is unchanged.)
The front/rear ride height seems to be about the same (or slightly lower front end); the rear is definitely not lower.

As far as I understand, getting lower springs is the usual way of lowering a car, but the original springs are still in place and untouched, so I wonder how this setup could have lowered the rear end? (Ie what other components affect the ride height?) How does the increased wheel angle (camber??) affect the car's handling?

Sorry about my poor chassis knowledge, I know hardly anything about the djungle of suspension and handling and have been trying to figure this out for quite a while now...

Any help would, as always, be greatly appreciated!

Regards,
Patrik
 

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Hi Mr J

hope you are well?

It is not hard to lower the rear using the SLS on the 3,8 - apparently you put some heavy weights in the boot which lower it to the required amount - then you turn the ignition to position 1 or 2 or the engine running (cant remember), and you take the weights off after which the level of the rear remains at the height it was with the weights in.

I am sure I have described this wrong - somebody help......
 

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Discussion Starter · #3 ·
Jahangeer said:
Hi Mr J

hope you are well?

It is not hard to lower the rear using the SLS on the 3,8 - apparently you put some heavy weights in the boot which lower it to the required amount - then you turn the ignition to position 1 or 2 or the engine running (cant remember), and you take the weights off after which the level of the rear remains at the height it was with the weights in.

I am sure I have described this wrong - somebody help......
Hi Jahangeer,
I'm fine thanks, how are you?
Hope you haven't hibernated the M5 yet; the Ford seems a little less exciting. :) Just as I'm enjoying the last few weeks of M5-driving, my clutch thought it was about time to start slipping. Will get it sorted next week, to a cost yet unknown...

Didn't know it was that easy to lower the SLS, its just that I don't think my replaced shocks are self-levelling... Or could that have been standard on the 535 too?
 

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Jahangeer said:
Hi Mr J

hope you are well?

It is not hard to lower the rear using the SLS on the 3,8 - apparently you put some heavy weights in the boot which lower it to the required amount - then you turn the ignition to position 1 or 2 or the engine running (cant remember), and you take the weights off after which the level of the rear remains at the height it was with the weights in.

I am sure I have described this wrong - somebody help......
Hi!
This should not be possible if the EDC/SLS is working properly. there is a fixed level sensor above the differential that makes the SLS/EDC to level itself to the same ride height regardless of the load, thats the point of the system.
If you pu a heavy load in the boot and start the car, it will jack itself up to the normal level. I fit don`t succeed at this there will be a "bong" from your OBC claiming EDC fault. Theoretically you could change the preset ride height by adjusting the sensor arm, but Why do this?
But this was not the question by Mr J anyway....

Mr.J: Have you measured the ride height? I`m pretty sure that there has been a thread about correct ride height, make a search.
If the EDC has been removed, then the previous owner must have replaced the damper struts also as the EDC dampers are a integrated design. The question is, from which car do the struts come from, the usual way is to replace the EDC items with ones from 3.6 M5 and the dampers also (the struts maybe same with the 535i) Are the dampers standard 535 items or the M tech ones as the damping on the standard ones is WAY too soft.
Are you sure that the springs are the 3,8 M5 ones (the question is if they fit the standard strut tower). But anyway I should think that the low rear end is due to lack of EDC/SLS and springs have sagged a bit (could be broken also, not unusual and propably more prone to do so with the softer dampers) This shows clearly as you lack the self leveling suspension.
I think that the increased camber at rear would increase understeer as the rear end grip is enhanced. It`s quite hard to tell though as I don`t have a clue how the changed components affect the overall geometry and damping characteristicts are changed also....

:cheers:
Sakke
 

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DrSakke said:
Hi!
This should not be possible if the EDC/SLS is working properly. there is a fixed level sensor above the differential that makes the SLS/EDC to level itself to the same ride height regardless of the load, thats the point of the system.
If you pu a heavy load in the boot and start the car, it will jack itself up to the normal level. I fit don`t succeed at this there will be a "bong" from your OBC claiming EDC fault. Theoretically you could change the preset ride height by adjusting the sensor arm, but Why do this?
But this was not the question by Mr J anyway....

Mr.J: Have you measured the ride height? I`m pretty sure that there has been a thread about correct ride height, make a search.
If the EDC has been removed, then the previous owner must have replaced the damper struts also as the EDC dampers are a integrated design. The question is, from which car do the struts come from, the usual way is to replace the EDC items with ones from 3.6 M5 and the dampers also (the struts maybe same with the 535i) Are the dampers standard 535 items or the M tech ones as the damping on the standard ones is WAY too soft.
Are you sure that the springs are the 3,8 M5 ones (the question is if they fit the standard strut tower). But anyway I should think that the low rear end is due to lack of EDC/SLS and springs have sagged a bit (could be broken also, not unusual and propably more prone to do so with the softer dampers) This shows clearly as you lack the self leveling suspension.
I think that the increased camber at rear would increase understeer as the rear end grip is enhanced. It`s quite hard to tell though as I don`t have a clue how the changed components affect the overall geometry and damping characteristicts are changed also....

:cheers:
Sakke
--------------

Yep Dr Sakke is right Mr J - I forgot to mention the bit where you have to adjust the screw at the bottom of the car - cannot remember wether its clockwise or anti-clockwise. Sorry.
 

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Discussion Starter · #6 ·
DrSakke said:
Mr.J: Have you measured the ride height? I`m pretty sure that there has been a thread about correct ride height, make a search.
Not yet, but I'll check that.

If the EDC has been removed, then the previous owner must have replaced the damper struts also as the EDC dampers are a integrated design.
Having studied the illustrations at realoem.com, I've come to the conclusion that the dampers are put inside the damper strut, which basically seems to be a tube for the damper..? I've been thinking that all dampers were an integrated design like the EDC - ie. one unit which flexes and has a support ring for the spring.
So it is about time I get things right! ouich (Btw: damper strut=fjäderben in Swedish?)

The question is, from which car do the struts come from, the usual way is to replace the EDC items with ones from 3.6 M5 and the dampers also (the struts maybe same with the 535i) Are the dampers standard 535 items or the M tech ones as the damping on the standard ones is WAY too soft.
I don't know about the struts but guess they're also from the 535 too.
There's a BMW-sticker with product number visible; I believe it's on the strut since its right behind the brake disc. Will check that one. Do they play a role in the ride height depending on where the "support disk" for the spring is?

I sincerely hope they are M-tech dampers but I don't know. What I do know is that the car is still incredibly fun to drive, although it would certainly be even better with the right stuff. The car still has a greater potential on the track than I can master, so I'm not yet in a hurry upgrading it.


Are you sure that the springs are the 3,8 M5 ones (the question is if they fit the standard strut tower). But anyway I should think that the low rear end is due to lack of EDC/SLS and springs have sagged a bit (could be broken also, not unusual and propably more prone to do so with the softer dampers) This shows clearly as you lack the self leveling suspension.
The owner told me that he kept the springs and changed the dampers only, so I believe they're stock. That's probably why the car feels firm enough to me although the dampers are softer than standard.
Haven't inspected the springs for a while, but none of them were visibly broken (in two pieces) when I last did. The strut tower is the part of the body containing the suspension, right?

However, Stevie just answered the ride height issue in another thread: "...but the back springs will be very low & soft. The rear spring of an SLS-car is too soft and short to work without the SLS damper."

I think that the increased camber at rear would increase understeer as the rear end grip is enhanced. It`s quite hard to tell though as I don`t have a clue how the changed components affect the overall geometry and damping characteristicts are changed also....
I believe you're right. At least it was rock steady when cruising the Autobahn! :M5launch:


Great info, thanks a lot Dr Sakke! :M5thumbs:


Patrik
 

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Det var så lite så.

yes, damper strut=fjäderben, and no; all are not integrated ie. as with the EDC dampers the damper is built in directly in the strut and cannot be changed as separate component-the whole installation must be changed.
Its quite usual for "normal" cars to have struts with insert type shocks ie the shock is a separate component that can be changed alone and the original strut stays on the car. they look quite a like , but the difference is that in integrated design the strut body (the outer tube) works as the cylinder for the damper. In insert design the damper has its own body within the strut.
I hope I explained it understandably..... :confused3

Good luck
Sakke
 
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