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Discussion Starter #1
help i am going to replace my sls suspension on an e34 m5 1989.i previously fitted coilovers all round but in devon our roads are way too rough and i still havent found spring rates which suit the car.i have the sls power steering pump and reservoir,good rear legs and two new springs.i have just bought a rear anti roll bar from the 525 touring which someone told me would help with underteer and finally 5ltrs of correct oil
how do i set the ride height?
should i replace the spheres?
any special way to bleed the system?
is the touring bar better than the m5?
need help quick as next ring trip in three weeks
 

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Ian, hopefully you have got some of your answers from reading Elekta's - EDC not active, thread. George K's recent suspension replacement thread will give you some pointers as well.
I don't know where you got the info regarding fitting a 525 touring arb, I understand that the bar you should be considering is the M5 touring arb. whether or not it is a worthwhile tweak is debatable, some think it's better others have said it can make the car a bit of a handful in the wet on public roads.
All the points you have raised have been well covered in the past so you'll have to employ the search function to get a fuller picture,I suggest you also try, www.bmwe34m5.com - faq's
Cheers.
 

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Can anyone provide more background to this?

I'm looking at going down the delete option although, having said that the sls pipes were replaced last year (thanks Chas :)).

Can anyone give me an idea of the possible options?
 

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Can anyone provide more background to this?

I'm looking at going down the delete option although, having said that the sls pipes were replaced last year (thanks Chas :)).

Can anyone give me an idea of the possible options?
Mate, I got my Koni/H&R rock hard & too low suspension replaced with a kit Faz found for me - which means the car does not get launched in bumpy corners, but still has less roll than the standard set-up.

Can't give the exact details on it as I don't know them, but I'm sure Faz would be happy to discuss if you give him a PM.
 

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Cheers Tony,

I've already PM'd the good man.

Strange this 'aint it? Only last week I was getting ready to throw her away, now I'm about to throw the rest of this years' salary at her :hihi:

Ah well, keeps me off the streets I guess.

cherrsagai
 

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help i am going to replace my sls suspension on an e34 m5 1989.i previously fitted coilovers all round but in devon our roads are way too rough and i still havent found spring rates which suit the car.i have the sls power steering pump and reservoir,good rear legs and two new springs.i have just bought a rear anti roll bar from the 525 touring which someone told me would help with underteer and finally 5ltrs of correct oil
how do i set the ride height?
should i replace the spheres?
any special way to bleed the system?
is the touring bar better than the m5?
need help quick as next ring trip in three weeks
Rollbar:

According to RealOEM the rear antirollbar on a 1995 Euro 525i Touring is 15mm diameter for the standard car and 16mm if it was the factory Sport trim with lowered and uprated suspension.

http://www.realoem.com/bmw/showparts.do?model=HJ52&mospid=47393&btnr=33_0283&hg=33&fg=45

If this is the case then you need to return the rollbar if you can. The M5 rear bar is 18mm on the 3.6 cars and early 3.8 cars, then when EDC-III Nurburgring "pack" came in with the wider wheels as standard it went up to 19mm.

The "someone told me" aspect comes in with the fact that a 3.6 car with staggered 17" wheels has quite a lot of understeer. The 3.8 cars with the wider wheels still had some understeer as you'd expect, as most manufacturers dial this in as standard as it is safer for nearly all drivers.

Adding the 20mm rear antirollbar from the M5 Touring (and the brackets, bolts, links and bushes to match, all in £100ish) will have the effect of bringing the car to a more neutral handling stance with sticky or larger-than-stock staggered tyres, but comes at the price of the back end breaking away harder and faster when it does let go. On a non-staggered or poorly shod car the balance may go into oversteer biased which is not recommended for anyone by the most talented drivers.

Remember the resistance to torsion does not go up linearly from 18, 19 to 20mm, each mm makes a far bigger difference than before.




Spheres:
Many early cars have had the spheres replaced. I have not so could not comment on their method of failure or symptoms.




Ride Height: (3.6 SLS, I do not have EDC-III personally)
I think this is on the FAQ link published for you, but if memory serves the car has to be fuelled up and the 200kg put over the rear axle (in the boot) before measuring the ride height. The valve near the rear diff that controls the SLS is altered which adjusts the height of the car. You have to get factory height which is measured from the point on the wheelarch directly above the centre of the wheel to the wheel rim where the tyre touches it below the centre of the wheel. I only have height figures for the E34's but not the M5.
It needs a new self-locking nut once adjusted and really a pit or proper garage lift to do. Read about it on the LAD SLS pages 330-12 of the Bentley book for a rough E34 overview before embarking on this thankless task.



'Ring trip:
If you have been driving the car on coilover or aftermarket suspension for years, then changing back to factory SLS and messing with the antirollbar to change the handling of the car a few days before going to the Nordschleife is not a very good idea. Take it easy, else we'll be seeing you on the Bongard lorry!





Seeing as you may have some coilovers, is it not worth getting them set up properly, each corner weighed and adjusted first with springs the same or near factory rates? (Assuming the dampers are decent ones that roughly suit the E34 M5)
I think you need to visit someone who does this kind of thing properly. Devon is in England and there's some bloke called Fonz or something like that who is not exactly local, but in the forties and fifties once worked on this kind of thing. He has a flat cap, a coal fire and uses and ear-trumpet, but he does know his stuff.

Regards

Ivan
 
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Having driven his car would back up Tony. Faz has a great kit that is due to be fitted to my car in about three weeks. I will report my own findings but my experience of Tony's car was an eye opener. I didn't think these lardy old saloons could feel so light and take bumps so well.

It was a very very impressive setup and a credit to the Faz. I think it's best as a job lot, which for my 3.8 is a bigger undertaking than the 3.6 cars, but, as per George K I've sourced some 540i front legs (used though to cut >£600 off my bill) which will form the basis of my conversion.

I don't have particulars but Farrell has sourced top mounts and other detail parts that are crucial to the kit, and it seems a thoroughly researched package. If anyone is in the Midlands in mid July (I will be playing for the first half of the month solid) and fancies a go (plus some of my wife's excellent cooking) please give me a pm. You will not be disappointed on either count, I promise.

I'm expecting to pay c. £1800 all round to delete SLS, maybe more, maybe less. It should be nearer £1500 on a 3.6 I believe. Either way this will be the end of suspension headaches for a few years and therefore represents a relative investment.
 

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The only thing that I would add is that having had all of the sls pipes , front to rear , replaced , it would be a shame to lose the original sls .

I was faced with this option with Sebring Sienna and decided to retain the original sls at the rear , replacing all sls pipes at the same time .

The front dampers were replaced with Hartge Bilstein dampers in the original 3.6 struts and H&R springs .

Sebring Sienna now handles like she is on rails and the original rear suspension has been maintained .

I am interested to see how , after such a push to maintain original EDC suspension previously and a complete rebuild package being made available , in recent months , the sentiment has changed to that of aftermarket suspension being preferable .
 

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David,

In my case it was a no brainer, as my car already had a H&R/Koni set on all round. Unfortunately it was too stiff and low, which meant it jumped from pothole to pothole and hit the sump/exhaust/diff everytime I went over a 'speed cushion' :mad:

The previous owner also removed the accumulators, so there really was no going back without a lot of expense. If you've got a 94/95 3.8 6-speed in good condition it's probably worth it, but for a 1990 3.6 worth £3k (i.e. mine) it wouldn't be :dunno:

For these others with EDC/SLS, I can only assume it's the cost. Original EDC struts for each corner would probably end up with a £4000 bill. Rebuilt ones will be a £1000 bill. An after-market set will be £500-£2000 depending on preference & spec. All of these will have similar labour & ancillary costs.

I know there's the rebuild service available now, and if this had been available 2 years ago I would probably have taken advantage of it for my old 3.8. The only concern I would have had was the lack of long-term on-road testing of these rebuilt units. I'm not saying they would fail within a year, but there's only a 3 month warranty on them, so if the worst was to happen you'd have the cost of another rebuild and another strip & fit.

I think some owners are just fed up with BMW's ever increasing prices and want to get out of their grip. We can do it with a lot of the parts from GSF/ECP, but some of the major item are dealer only.

I bet if Phil Crouch found a direct replacement Quaife gearbox for £1500, a few of use would eschew the BMW/rebuilds and get one of them (well I would, especially if it was a 7-speed sequential) :hihi:
 
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Discussion Starter #10
well i did replace the sls as my old units are all still good. back to very good handling but not adjustable. ride height looks right but dash still comes up with a fault on some trips. not as fast round the ring but much more comfortable .have managed to get a staggered set of throwing stars so i will fit these next and decide which way to go from there.also found ap racing 6pot calipers which will sort out the brakes if i can find the correct discs in 343 x 32 mm:M5launch:
 

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The only thing that I would add is that having had all of the sls pipes , front to rear , replaced , it would be a shame to lose the original sls .

I was faced with this option with Sebring Sienna and decided to retain the original sls at the rear , replacing all sls pipes at the same time .

The front dampers were replaced with Hartge Bilstein dampers in the original 3.6 struts and H&R springs .

Sebring Sienna now handles like she is on rails and the original rear suspension has been maintained .

I am interested to see how , after such a push to maintain original EDC suspension previously and a complete rebuild package being made available , in recent months , the sentiment has changed to that of aftermarket suspension being preferable .
Hi David

This is only my opinion and personal decision and I suspect most 3.8 owners may not agree but I've decided EDC is impractical for me.

I want to use my M5 everyday because I love it and IMHO its the best way to minimise decay. EDC/SLS is a very complicated system, and pipes, accelerometers, ECU, pump, accumulators, sensors, as well as 4 outrageously expensive shocks can all cause a check control warning. With my previous M5 I had the time to take it to garages between services, now I don't - nor the money. The rebuilt EDC shocks are a great solution but they don't help the durability of all the other components, and are still of unproven durability themselves.

The kit I'm hoping to fit will exclude all the other complicated components, exclude the chance of an SLS or EDC warning, and should be very durable high quality hardware. The fact that initial experience suggested it was also much better on the road than the ageing stock suspension on my previous LE 44/50 clinches it. Some staggered TS's, a fat rear roll bar, and that's suspension to bed for several years:applause:
 
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