Question about lowering an E38 740iL with sls

[PJs e32]

My mate has a 2001 E38 740iL and wants to lower it, he has purchased a set (front and rear) of lowered springs (not sure of the brand) and he is getting conflicting information in regards to if he should fit the rear lowered springs as well as the front. Some are telling him to only fit the front springs, and others say to fit both (front and rear).
Just thought I would ask the guys that have lowered their E38 for their opinion or what they have done to their cars with sls.
Thanks in advance.
PJ

[tjpike]

The problem with SLS is that the rear springs need to be specially designed such that it accommodates the suspension travel of the SLS system. If your friend bought regular springs they will not fit as I believe that SLS springs are longer. The fronts should work though. Although it might shorten the life of the shock. If you really want to lower the car the proper way, I suggest you look into name brand companies like H&R or B&G, they make springs for cars with SLS.

[acspecialists]

+1

[PJs e32]

Thanks for your reply tjpike, he has purchased the springs set, I will ask him what brand, and if it is specifically for a car with sls.
I did say to him that he wouldn't be able to install the rears, as I thought it would upset the sls system, and correct me if I am wrong, but I thought/think the rear springs are weaker as to allow the sls system to regulate the height more that the spring.
i also just thought I would put the question up here to hear from people that have lowered their cars, and to confirm my thoughts.
thanks again, PJ

[chrisn7]

The rear is already at an ok ride height, its the front which is too high. Lowered mine with Eibachs who sell a front and rear set specially for E38 with SLS (2029-140)

[OoVee]

The rear is already at an ok ride height, its the front which is too high. Lowered mine with Eibachs who sell a front and rear set specially for E38 with SLS (2029-140)

I was thinking of doing the same with my 750i with edc and sls. Was it an easy job and did the sls make replacing or removing the spring more difficult compared to regular shocks?

[chrisn7]

SLS is only on the rear, and I didnt change the rear springs, but you can de pressurise the system at the control valve between the rear wheels, before releasing the fluid line to the strut. Keep in mind that the spring pan at the rear is very prone to rust, and sound ones are hard to come by as they are not available as a separate part, even though they can easily be removed from the strut. I suggest you do the fronts first, then see if the stance is right for you, before tackling the rears.

At the front, you will need a big, good quality spring compressor, due to the diameter of the springs. You cant use typical DIY straight clamps due to the barrel shape of the spring. Its also useful to have the (inexpensive) tool to spread the clamp that secures the strut to the hub.

[CPHES]

Read this - but do the fronts first, and see http://www.bimmerboard.com/forums/posts/636513

[740ilDuke]

I installed OE 740i Sport Springs on a former 750iL I had, dropped the nose and had no issues. Not sure if I'll do that on my current 750iL, aim is to keep it factory.