BMW E39 530i M-Sport Suspension suggestion

[Luka08]

Hello, i am planning on changing front and rear struts. My car came with M-sport suspension II from factory and it sits quite nice right now(everything is OEM). i want to change struts with Bilstein B4 but i see that my OEM sachs strut axis is lot shorter than Bilstein, so i am thinking that it will cause to raise the car up. Please give me suggestions about this

[MotorMouth93]

Koni yellows have been pretty close to stock for me, my 540 has the Mtech suspension II as well, I adjusted them as per some forum threads on M5board. Some people just set them to full soft as well.

Apparently, if you call Bilstein they have a stock Mtech II replacement option as well that isn't listed most places.

[Aubergine]

Hello, i am planning on changing front and rear struts. My car came with M-sport suspension II from factory and it sits quite nice right now(everything is OEM). i want to change struts with Bilstein B4 but i see that my OEM sachs strut axis is lot shorter than Bilstein, so i am thinking that it will cause to raise the car up. Please give me suggestions about this

Agreed. You will need the Sachs versions with the red label to be closer to the M Tech (Sport) suspension. I recommend downloading the PDF catalog from their site and shopping using part numbers.

The B4 option will probably be okay, but honestly, my friend paired B8s with new M Tech (Sport) springs on his Sport Pack 528i and it rides and handles very well. Just be warned that the ride is quite a bit firmer.

In regard to Koni, The Sports (Yellow) front struts have been NLA for I6 E39s for a while. The Special Actives are great and my mother has them all around on her E39. It rides very smoothly and just the right level of tightness. I would pass on their Street model.

[kallekula]

That’s why I bought Sachs OE. Not interested in feeling every little pebble on the road.

[Jason5driver]

That’s why I bought Sachs OE. Not interested in feeling every little pebble on the road.

LOL !
Oh so true ! lol ....

- - - Updated - - -

Agreed. You will need the Sachs versions with the red label to be closer to the M Tech (Sport) suspension. I recommend downloading the PDF catalog from their site and shopping using part numbers.

The B4 option will probably be okay, but honestly, my friend paired B8s with new M Tech (Sport) springs on his Sport Pack 528i and it rides and handles very well. Just be warned that the ride is quite a bit firmer.

In regard to Koni, The Sports (Yellow) front struts have been NLA for I6 E39s for a while. The Special Actives are great and my mother has them all around on her E39. It rides very smoothly and just the right level of tightness. I would pass on their Street model.

I have been on the fence over the new Koni Red Actives , or OE Sachs stuffs ...
Even the Koni Str's ?

[chuckesteeze]

I have been on the fence over the new Koni Red Actives , or OE Sachs stuffs ...
Even the Koni Str's ?

I have all three of those on various cars. My 525iT has the Koni Special Actives (AKA Reds, $$), my family's 530i sport package has stock Sachs ($$$), and my Fiesta ST has Koni STR.T (AKA orange, $).

The Koni reds are definitely the stiffest, and driving on crappy roads with them sucks. Expansion joints that I'd hardly notice with the Sachs will cause me to wince with the Koni reds. That said, I'll pick the reds for spirited backroads driving every time. Ditto for freeway driving, where the wagon with the reds feels most stable and planted, not that the Sachs are bad in this regard. I knew what I wanted when I bought them though, and can accept the compromised ride quality around town in exchange for excellent composure in the twisties.

If you've got the money for Sachs and want to retain a comfortable ride everywhere, get them. The 530i on stock sport suspension can still dance, don't get me wrong, but there is definitely a greater emphasis on luxury. I feel like Sachs also has better QC than Koni, FWIW.

I'd only get the Koni orange shocks if cost is the primary factor. They work fine in my FiST, where the goal was more compliance on shitty roads and keeping running costs as low as possible. While the Fiesta is a wildly different platform than the E39, my guess is they would feel more similar to stock Sachs without the refinement and build quality. Koni does offer a lifetime warranty which is nice, just be sure to read about how you go about using it.

[Luka08]

But if i go with bilstein b4 , will it cause to raise the car up? I live in a different country and at the moment there is not available OEM sachs with red label so thats why i am considering bilstein b4

[StephenVA]

With poor quality roads and lots of pot holes and such, you need a compliant suspension. OE set up (shocks, struts and springs) will get you 90% of what you are seeking. Add in a larger rear sway bar (M5 recommended) and new bushings w/new links Front & Rear will provide the roll control that so many seek here on the forum. I would replace your REAR bushing with Poly and use these STEEL replace brackets as they are cheap and will use the same fasteners from the factory.

OE Brackets replacement:
https://www.ebay.com/itm/14487091402...AAAOSwVClfaS6z

Bushings
There are lots of Euro suppliers who make rear bushings for the E39 suspension. Your rear bar is currently 14mm. The M5 bar is 16.5mm so that is the hole size you need for the bushings.

Note: BMW E39's have three OE size bars depending on engine/suspension options.

Bar Sizes for Euro production
MSport			Part No
M Sports suspension	S704A=Yes	Dia: 13MM	33551092835
National version eastern Europe
	L816A=Yes	D=14MM	33551092834
or
M sports suspension II	S705A=Yes
or
Poor road package	S815A=Yes
Stabilizer, rear		D=15MM	33531093816

Measure what you have and move to the M5 bar for better handling.
33552229136 Stabilizer, rear, D=16,5MM

[haolibird]

I put B4's on my '03 540, and deeply regretted it.
They were entirely too soft, and handling was poor.
I went cheap knowing I was going to sell the car, and thought about putting it back to stock.
It was a bad decision, especially for the next owner...

I have B6's on my current '03 540, and they handle excellent.
Stiff, but excellent.

My $0.02...

[Jason5driver]

I put B4's on my '03 540, and deeply regretted it.
They were entirely too soft, and handling was poor.
I went cheap knowing I was going to sell the car, and thought about putting it back to stock.
It was a bad decision, especially for the next owner...

I have B6's on my current '03 540, and they handle excellent.
Stiff, but excellent.

My $0.02...

Were the B4’s similar to the Sachs stuffs ?

[Aubergine]

I have all three of those on various cars. My 525iT has the Koni Special Actives (AKA Reds, $$), my family's 530i sport package has stock Sachs ($$$), and my Fiesta ST has Koni STR.T (AKA orange, $).

The Koni reds are definitely the stiffest, and driving on crappy roads with them sucks. Expansion joints that I'd hardly notice with the Sachs will cause me to wince with the Koni reds. That said, I'll pick the reds for spirited backroads driving every time. Ditto for freeway driving, where the wagon with the reds feels most stable and planted, not that the Sachs are bad in this regard. I knew what I wanted when I bought them though, and can accept the compromised ride quality around town in exchange for excellent composure in the twisties.

If you've got the money for Sachs and want to retain a comfortable ride everywhere, get them. The 530i on stock sport suspension can still dance, don't get me wrong, but there is definitely a greater emphasis on luxury. I feel like Sachs also has better QC than Koni, FWIW.

I'd only get the Koni orange shocks if cost is the primary factor. They work fine in my FiST, where the goal was more compliance on shitty roads and keeping running costs as low as possible. While the Fiesta is a wildly different platform than the E39, my guess is they would feel more similar to stock Sachs without the refinement and build quality. Koni does offer a lifetime warranty which is nice, just be sure to read about how you go about using it.

I must say I have to kindly disagree with your assessment of the Koni Special Actives (FSDs/Reds). They are firmer than the OE Sachs options (Standard and Sport) but have a compliance you just cannot get with a Bilstein. They smooth our super rough roads and potholes but firm up nicely in corners. I feel they make an E39 what it should have been to begin with.

All that said, we had a set of front struts go bad after 50k miles and then the variable dampening did not work and they were super firm. Koni covered new units (no labor) under warranty and it was back to the good feelings after we replaced them. I have to wonder if yours aren't working correctly when you describe them as very firm.

[StephenVA]

firm is subjective as everyone's butt dyno is either compliant or useless

[Nfs021]

Roads play a factor too. Have Bilstein B6 on my M5. On the crappier roads, the ride can be a bit harsh. On better roads it's fine. Despite that though, the car handles great with them. Of course I also overhauled the rest of the suspension as well which obviously helps lol.

I've heard that B4's are basically like factory Sachs. Mixed reviews, some liked them, others didn't. Looks like Rockauto has aftermarket Sachs. But pretty sure they are for M-Tech 1 suspension, not your M-Tech II. Otherwise if you want factory ride, bend over for genuine parts.

[Aubergine]

Roads play a factor too. Have Bilstein B6 on my M5. On the crappier roads, the ride can be a bit harsh. On better roads it's fine. Despite that though, the car handles great with them. Of course I also overhauled the rest of the suspension as well which obviously helps lol.

I've heard that B4's are basically like factory Sachs. Mixed reviews, some liked them, others didn't. Looks like Rockauto has aftermarket Sachs. But pretty sure they are for M-Tech 1 suspension, not your M-Tech II. Otherwise if you want factory ride, bend over for genuine parts.

It is worth noting that Sachs own catalog lists M Tech I and M Tech II sharing the same dampener. The info on Sachs in really scattered so the only way I learned this was by downloading the PDF catalog and shopping by part number.
https://aftermarket.zf.com/go/en/sac...2iqI4puRzZZ_dE

[patrm99]

I put B4's on my '03 540, and deeply regretted it.
They were entirely too soft, and handling was poor.
I went cheap knowing I was going to sell the car, and thought about putting it back to stock.
It was a bad decision, especially for the next owner...

I have B6's on my current '03 540, and they handle excellent.
Stiff, but excellent.

My $0.02...

Fully agree on the B4's being way too soft particularly when cornering at speed. I plan to install Koni yellows as the adjustability is appealing.

BTW, I suspect I am the "next owner" haolibird refers to above !

[Jason5driver]

Oh snap ! lol ...

[MotorMouth93]

Fully agree on the B4's being way too soft particularly when cornering at speed. I plan to install Koni yellows as the adjustability is appealing.

BTW, I suspect I am the "next owner" haolibird refers to above !

Keep in mind that the Konis are only adjustable for rebound and not compression. You also have to take the rear shocks off the car to adjust them which is fun.

If you take the front shocks off I'd recommend putting a reinforcement plate between the shock and the chassis to prevent them from bowing out.

[haolibird]

Patrick,

I suppose you are...

Look at the bright side, had I put the B6's on, I would never have sold the car!
My wife is STILL pissed I let that one go.

Hope all is well.

Tom

[chuckesteeze]

I must say I have to kindly disagree with your assessment of the Koni Special Actives (FSDs/Reds). They are firmer than the OE Sachs options (Standard and Sport) but have a compliance you just cannot get with a Bilstein. They smooth our super rough roads and potholes but firm up nicely in corners. I feel they make an E39 what it should have been to begin with.

All that said, we had a set of front struts go bad after 50k miles and then the variable dampening did not work and they were super firm. Koni covered new units (no labor) under warranty and it was back to the good feelings after we replaced them. I have to wonder if yours aren't working correctly when you describe them as very firm.

You could be right about them being defective. I know Koni QC doesn't have the best reputation.