03 M sport suspension alternative

[bostonaudi]

Like others with 03 M sport 540i’s with the aluminum M5 dampers, I faced about $1600 for a set of replacement dampers from BMW. Ouch.

The stock springs also leave a bit of wheel gap up front, also was looking for a mild drop and didn’t want coil overs. Went with Eibach Pro-kit springs and Koni STR.T dampers after talking to a Koni rep on the phone.

This turns out to be a great alternative to the good but very expensive factory parts. The Eibach’s provide a bit of drop and the Koni’s are about 10% stiffer than stock. Car rides and handles great. Koni Yellow sport shocks also a good choice, for this car I didn’t need adjustment and the STR.T’s are set perfectly for spirited street driving. The car is also fine loaded with 4 adults. The Eibach’s drop the front perhaps a tad more than I wanted but overall pleased with the setup.




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[indy525]

Looks great.

Question: Do the orange koni's have the adjustable spring perches like the yellows? I had the yellows with vogtland springs on my last e39 and starting to decide on what to do with my 540.

[Iamthebull]

I recently installed Koni yellows with Eibach on my 02 Sporr. I agree, too low in the front. I reused the factory bumpstops, bottoms out more than I like.

[JimLev]

I recently installed Koni yellows with Eibach on my 02 Sporr. I agree, too low in the front. I reused the factory bumpstops, bottoms out more than I like.

You could raise it up a little like I did with some spacer rings on the bottom of the strut tubes.

[Iamthebull]

You could raise it up a little like I did with some spacer rings on the bottom of the strut tubes.

Oh yea? Where did you source those from? Thanks Jim!

[BimmrMeUpSnotty]

Jim had them made, interested in this myself, as I too, think that the Eibach pro front springs drop the front end a tad too low. Not hard to fab up, just need to do some measuring of the outer diameter of the lower front struts, source some tubing whose inner diameter fits right over the struts lower tubing up to the stops, figure, what, 3/8" or so wide, cut them equally, walla, custom spacers. I'd use aluminum so as not to introduce galvanic corrosion into the equation.

[JimLev]

I had a machine shop make them from aluminum for me.
The H&R springs I bought dropped the front 1.5" which looked cool but the lower part on the bumper and the belly pan was scraping on just about everything.
I'll dig up the drawing I made and post it here soon.

[JimLev]

Here's the ring info.
After I had them made I used a hacksaw to put the slice in them to make it easier for me to slide them onto the bottom of the strut tube.

StrutRings_1.JPG

F_Eibach7.JPG

F_Eibach8.JPG

StrutRings_1a.JPG

Eibach14.JPG

[f355spider]

I went with Suspension Techniques ST-X coilovers (made by KW in Germany), then I have adjustable height at all corners, about $820 for the kit with their springtime $100 rebate. Agree, the M5 shocks and struts were simply too big a bite to take for replacements.

[bostonaudi]

To follow up, the rear STR.T’s have 3 slots for the spring perch so unlike Bilsteins you can adjust them to factory height. I have scraped a few things here and there, like the idea of a spacer to raise it a bit.


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[Bojangles311]

@Bostonaudi,
I know it’s an old post, but not sure if you have any more photos of your set up but I’m looking to do the same suspension set up with the Koni STR.T and Eibach pro kit.
I also have a 2003 E39 540i M Sport /6spd.

After driving it for a few years, how’s it holding up? Thanks!

[bostonaudi]

The 540i held up great. So what I finally did to fix the front being too low was to reinstall the factory springs up front, and left the rear Eibachs in. This then created perfect front rear stance. I think the front Koni’s may have a slightly lower front perch height.

I have an E39 M5 now and at 130k miles about to do it’s suspension and facing same question , pay up for OEM or do Koni’s.

IMO a stunning E39:

[Jason5driver]

How's the ride of the Koni STR's ?

[Asphyx666]

how did u make this m pars fit on the e39? correct me if im wrong but e39 wheel hub is slightly bigger than the e38 (74 vs 72)

[Nfs021]

how did u make this m pars fit on the e39? correct me if im wrong but e39 wheel hub is slightly bigger than the e38 (74 vs 72)

BMW also made m pars to fit the E39's bore. Got them on my M5.

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[crazy4trains]

If you're going to throw numbers out there, the e39 center bore is 74.1 mm, not 74 mm.

[peter540]

When I overhauled my suspension, I experimented with a number of setups:

* Fortune Auto coil-overs. I was part of the beta group when they were developing this product. FA is a top-notch player in the coil-over space. While I liked the flexibility to adjust the ride height, they rode far too hard for me, and I ultimately couldn't take it anymore.

* Eibach Pro-Kit lowering springs (like the ones the OP used) with Koni Yellow shocks/struts. As with the OP, I found the front was too low for my liking, and I also felt that the setup was too softly sprung.

* Dinan M5 lowering sprints with the Koni Yellows. This is the setup that ultimately worked best for me. Very happy with the ride height and ride quality. Good luck finding the Dinan springs specific to the 540 -- they stopped producing them. I did a ton of research, even connecting with another 540 owner who went with the M5 Dinan springs and who was happy with them (rear springs are the same for both the M5 and 540; the front springs had different rates, since the M5's motor is heavier than the M62TU). The M5 front springs have been just fine. Here's a photo of how it sits. Just perfect for me...
BMW540.jpeg

I hope this saves some of you some time, money and aggravation. I wish I'd thought to go with my current setup from the beginning -- I spent a lot of money on buying the wrong parts and going through the labor to change out everything (the rears are no joke, since you have to remove the rear seat back and rear parcel shelf to even get to the rear shock mounts).

--Peter

[bostonaudi]

how did u make this m pars fit on the e39? correct me if im wrong but e39 wheel hub is slightly bigger than the e38 (74 vs 72)

03 M sport 540’s came with these wheels when new. They are definitely one of the finest wheels BMW ever did.


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[bostonaudi]

How's the ride of the Koni STR's ?

Excellent - the valving is very close to the original aluminum shocks, almost indistinguishable and at much lower cost. I would definitely recommend if you want an install and forget setup. Otherwise the suggestion above to use the Dinan M5 setup also very good.