[ObsidianX]

I'm about to place the order for parts for the first mods to my 2011 335i xDrive (TiAg E90 Sedan with Chrome Trim around the windows). I'm going after a clean look. The car is primarily an interstate highway cruiser back and forth to work.

Tires: Michelin Pilot Super Sport
F: 235/40R18
R: 265/35R18

Wheels: VMR V703 (CSL Style) in Super Silver
F: 18x8.5 ET35
R: 18x9.5 ET45

Suspension: KW V1 Coilovers

I'll swap out the wheels in the winter for a square set of VMR V718 (18x8.5 ET35) that I already own paired with a set of 235/40R18 snow tires. I won't be able to run the PSS year round here in New England.

I'm also going to install a set of LUX H8 180 to whiten the Angel Eyes from their OE amber color.

Initial thoughts? Am I on track? Thanks in advance for your inputs!

[matteblue3er]

Do you plan on tracking the car?

Unless you specifically want height adjustment, you can save some money by just getting koni yellow or bilstein b8s and lower springs

[ObsidianX]

Originally Posted by matteblue3er

Do you plan on tracking the car?

Unless you specifically want height adjustment, you can save some money by just getting koni yellow or bilstein b8s and lower springs

No, I don't plan on putting it on the track. Part of the reason I am thinking coilovers is I want to ensure both the front and back are at the same height and I am concerned some springs will slam the car more than I am interested. I'd like the height to be similar to a stock M3.

Is there are particular brand's sport springs and shocks/struts that give a nice clean and even look on an E90 xi?

[matteblue3er]

I'd go with koni yellows and OEM sport springs. You can remove the 1/4" reinforcement plate between the strut hat and tower to lower the front a bit.

[NiNeTyOne]

The Eibach pro springs are almost exactly the drop he wants and are superior springs to the sport springs. Eibach ERS are even better, but linear and less ideal for street use.

The Eibach pro's are rate matched to the Bilstens and FSD's (I know as I have them on the e91 while I await the new Ohlins setup, and they are pretty damn good).

The FSD tech is Koni's take on Ohlins DFV system, and if you run them on a shock dyno the advantages are pretty clear over traditional Koni's or Bilstein twin-tube dampers. They are under damped for track applications (hence my swapping them for Ohlins), but on the street they are very good. Disregard reports of them 'losing their magic' as I have well over 15k on mine and they are as good as they day they went in.

Set up like this a xDrive car will essentially sit at the RWD e92 sport suspension or m3 ride height. The front will be raked about 7mm, which is almost perfect for on throttle balance.

[ObsidianX]

Originally Posted by NiNeTyOne

The Eibach pro springs are almost exactly the drop he wants and are superior springs to the sport springs. Eibach ERS are even better, but linear and less ideal for street use.

The Eibach pro's are rate matched to the Bilstens and FSD's (I know as I have them on the e91 while I await the new Ohlins setup, and they are pretty damn good).

The FSD tech is Koni's take on Ohlins DFV system, and if you run them on a shock dyno the advantages are pretty clear over traditional Koni's or Bilstein twin-tube dampers. They are under damped for track applications (hence my swapping them for Ohlins), but on the street they are very good. Disregard reports of them 'losing their magic' as I have well over 15k on mine and they are as good as they day they went in.

Set up like this a xDrive car will essentially sit at the RWD e92 sport suspension or m3 ride height. The front will be raked about 7mm, which is almost perfect for on throttle balance.

Thanks! Do you also recommend the yellow Konis for shocks/struts with the Eibach Pro Springs?

I'm surprised the recommendations against the KW V1 coilovers. I take it these are overkill for what I am looking for?

[NiNeTyOne]

Originally Posted by ObsidianX

Thanks! Do you also recommend the yellow Konis for shocks/struts with the Eibach Pro Springs?

I'm surprised the recommendations against the KW V1 coilovers. I take it these are overkill for what I am looking for?

I'd do FSD's before the Yellows. Honestly the Yellows are about 20 year old damper tech. The V1's are not really that great a damper. Sure, they are coilovers, but honestly, they are C tier coilovers using old uninspired damper tech.

If you're curious about where Koni's new tech is coming from, have a look at this little press announcement here.

For street cars right now the best performance for the dollar is either DVF (Ohlins at around $1800-ish w/springs) or FSD's (about $900-ish w/springs) dampers, especially with the crappy roads in most NA urban environments. The DVF's are custom, and they typically rate match ERS springs for the damping setup for the vehicle. ERS Springs are LINEAR, not progressive rate.

Again, the FSD kit for the e9x is rate matched to the Pro spring kit. Make sure you get the ones for xDrive, I had to order mine from Germany, but shipping was only $60 so no big deal there.

Some have complained about the FSD's 'losing their magic' but I instructed on mine recently and after 15k miles my lap times are nearly identical to when they were new, so that just doesn't hold water.

While you're in there changing the fronts, replace the front thrust arm bushing with poly. You'll thank me later.

There have been some recent tests where the Koni Sport dampers were compared to the FSD's and the results were pretty revealing. Note these tests were done with OE springs and dampers so you can expect even better results with good springs.

[matteblue3er]

Originally Posted by ObsidianX

Thanks! Do you also recommend the yellow Konis for shocks/struts with the Eibach Pro Springs?

I'm surprised the recommendations against the KW V1 coilovers. I take it these are overkill for what I am looking for?

I know you don't want to go that low but KWs are known to blow if you lower them too much. That's because they have fully thread strut bodies and they don't warn you that lowering past a certain range will put them outside the acceptable valving range.

I won't promote a company that sells a product that is setup to basically fail. They very well know many people will lower outside the valving range yet give no warning or marketing to not do so. When it comes time to claim warranty, it's very easy to see where the coils have been set and they will deny the warranty claim.

Pretty unethical and there are better options out there.

[ObsidianX]

Will the Koni FSD struts and shocks lower me if I use the BMW OE springs? My only concern with using springs is I won't like the rake height (either too low or uneven front to back).

I'm having trouble finding Eibach Pro Kit springs specific for the XI on the Eibach Europe website.

[NiNeTyOne]

Originally Posted by ObsidianX

Will the Koni FSD struts and shocks lower me if I use the BMW OE springs? My only concern with using springs is I won't like the rake height (either too low or uneven front to back).

1.25" rear, 1.33" front, which is ideal balance. You need a tiny bit of rake or the car does stupid shit under heavy acceleration. It also improves handling dramatically at high speed.

The lowering comes from the springs though, if you use the OE springs it should be exactly what you have now, which is too high unless you're offroading the car. :/

This puts you almost exactly at the same height as the e92 with factory sport suspension. It will be a tad high at first but settles in about a week.

[3p3rk5xi]

Great info guys, I have a 2008 E92 33XI and will be looking to do the same thing come spring. So Koni FSD with what springs ? will give me little to no front monster truck gap, if I plan on running 18' APEX wheels... currently I have 19" BBS but feel they may be to large and heavy

[NiNeTyOne]

E90, 91 or 92?



The Eibach Pro springs are great street springs. I'll look into the ERS rates if you are interested, as I have a contact within Eibach in Germany. They will be more expensive.

Vendors online abound. Google.de is your friend.