E24/E28 suspension replacement questions

[pbrutsche]

Hello all,

I am the new owner of a 1989 635CSi (E24 chassis), and my car needs new a front AND rear suspension.

My self-leveling rear suspension is malfunctioning, and I am debating doing an "SLS delete" (disable it and put in standard coil springs & shocks) as an option that will be cheaper in the long term.

I am looking for something that is as close to factory ride height & ride quality as I can cost-effectively get it. I'm not opposed to lowering it an inch or so if that is my only cost-effective option. I am not looking for a "sport" suspension, as this car will not be raced or tracked.

The 5-series suspension up to 1988 (E28) is identical to the 1980s 6-series, so anything anyone can suggest for an E28 will apply to my car.

I would greatly appreciate any suggestions anyone can make, even if someone can point me in the direction of a common brand of coilover that I can contact to figure out what will get me the closest to what I want.

[circuit.heart]

If RockAuto doesn't have what you need, you can piece together the necessary bits from eBay.

Front dampers: https://www.ebay.com/itm/254776627782
Rear dampers: https://www.ebay.com/itm/264926716130
New BMW springs are cost-prohibitive so I would probably eat the 1" lower ride height with something like this: https://www.bimmerworld.com/Suspensi...-6-Series.html

That is the closest combo to a factory experience that I could find for not insane money. If you are looking at any combo above $1000, just weld in BC Racing coilovers and choose soft springs at order time to deliver the ride comfort.

[RBNetEngr]

Definitely stay away from BC coilovers if you’re interested in a close to stock ride. BC coilovers will give you a firmer ride, and will likely lower the ride height. If you want to keep things at or new factory performance levels, it looks like Bilstein B4 shocks and strut inserts will give that to you. For an small increase in firmness, the Bilstein B6 will give you that improvement.

While you are planning to keep your stock springs, you should plan to replace all bump stops, gaskets, and perhaps even some mounting bolts, while you replace the shocks and strut inserts.

I did a quick check, and both Bimmerworld and Turner Motorsports have everything you need. They also have helpful people available to answer questions and help you select everything you’ll need.


-rb

[pbrutsche]

Thanks guys. I was looking at H&R springs + Bilstein B4 struts. A local BMW shop said the OE parts for a E28 528e will fit but will probably compromise ride too much, even though it's the cheapest option.

Am I correct in reading that the H&R springs don't need any camber adjustments, and if I have too much camber I should look at suspension bushings?

[RBNetEngr]

If you go with aftermarket springs, which are generally stiffer and will lower the ride height, then the B4s are not the right shock or strut to use with them. The B6/B8 would be a better match. Generally, the B6 and B8 are valved the same, but the B8 has less damper travel, to better match shorter springs.

But doing so will go against your original statement wanting to maintain stock ride comfort and height.

Given the longevity of Bilstein dampers, don’t look for a cheap solution. Expect to spend good money for quality parts and installation, and it will last longer than the car will.


-rb

[circuit.heart]

Absolutely no Bilstein B6/B8's. I don't know who decided on the damper valving for that product but it's extremely overdamped with a lot of force on compression impacts. I have had them on my car once, and literally bent a wheel every time I drove over a railroad crossing above 20mph.

B4's with mild lowering springs will work, but Sachs is better. If you managed to find OEM springs, use them, unless the car they came off of is significantly lighter than your E24. For example, E28 535i springs I'd expect to work on a 635.

[pbrutsche]

6 month update: I ended up going with 535i springs and Bilstein B4s front and rear

[Gus Underfoot]

6 month update: I ended up going with 535i springs and Bilstein B4s front and rear

I really should have bought B6 as I don't mind a firm ride but now having bought the B4s and they are installed I discovered that you can't find the mythical H&R OE Sport springs (maybe I can find them for an E30 and they MIGHT work). Springs on my car have long since vacated, with 200K miles LOL.

That being said I guess I can suffer the new regular springs and return the H&R sports that are on the way but it's not really what the is was about but whatever.

Where did you get your springs and how do you like your setup now as that is basically what I would be winding up with. Thanks in advance.