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      10-29-2020, 10:57 AM   #24
435i_Phil's Avatar

Drives: 2015 BMW 435i Xdrive Sportline
Join Date: Mar 2020
Location: Bucks County

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Originally Posted by LYTSOUT View Post
I love my F30 xDrive, but my biggest issue from day 1 has been the suspension. Too tall, too soft, too floaty, etc. This is my 5th BMW, and (besides the X3) it's by far the softest, most Buick-like ride I've experienced, even with the EDC in Sport mode. I had planned to flash the Dinan Shockware, but sadly, my car was one of the [supposedly] rare cars that wouldn't accept it so my options were:
A) do nothing and be miserable
B) lower it on springs but that wouldn't fix the dampers
C) do springs and EDC compatible dampers (like the Bilstein B6, etc) but that would give a potentially uneven drop front-to-rear
D) do non-EDC-compatible coilovers (KW, PSS10, etc) but lose the EDC functionality
E) use an EDC-compatible coilover (B16 Damptronic) and tick every box

After a TON of research, I decided on the Bilstein B16 Damptronic coilovers which is the B16 version (similar to the PSS10) that plugs directly into the OEM EDC and is activated by the center console's Comfort/Sport button, exactly as the OEM dampers do rather than having to turn the knob under the car like the PSS10.

I haven't seen any first hand reviews of this kit so I suspect I may be one of the first adopters, at least in the Bimmerpost community, so I feel compelled to do a thorough write-up.

Cost: not cheap. $2,586 shipped from

Installation: relatively straight forward. Biggest issue was the strut nut where the top of the damper inserts into the top hat. It takes a special socket attachment, but the one I purchased (I think it was 18mm?) only fit the rear OEM strut. The front was larger (19mm?). To make matters worse, the new dampers used an even different, larger size (21mm?) so if you really want to do this right, get a full set of these stupid sockets. I ended up just tightening them down with an open ended wrench with an allen wrench stuck through it. Unfortunately, I was unable to torque them with that method. Oh, and you have to remove the entire front fender liner to get to the OEM EDC plug, but that was no biggie, just a minor surprise.

It's hard to explain the strut nut so here's how it works:

This is the one I bought which only worked for the OEM rear

This is the set you'd (probably?) need to do the whole job:

You'll also need a spindle spreader b/c the spindle his held on via tension:

Performance: I've put about 1000 miles on them so far so over the course of about two months I've got a very good idea of how they're doing. I'm not going to lie like so many others around here and say "THIS CAR NOW HANDLES LIKE IT'S ON RAILS!!!", but what I will say is that handling is dramatically improved. Gone is the floatiness, the dive with hard braking, the squat with hard acceleration, and much of the lateral body roll with cornering (but not all of it). There's still a noticeable difference in Comfort vs Sport. It's hard to quantify, but I'd definitely say that Comfort is tighter than OEM Sport used to be, and Sport is even tighter still. But neither of them are uncomfortable whatsoever, even on shitty midwestern roads, and although I haven't driven them back-to-back yet, I'm pretty sure my car is still softer in Sport than my dad's F80 ZCP in Comfort.

Generally speaking, it's a very good, compliant yet firm, sporty ride. Basically this is more-or-less what you might expect from a proper OEM sport suspension in a German sedan (rather than the joke of a suspension that came on the car). My only complaint is that they sometimes feel underdamped, but this is only noticeable upon braking. It's not overly dramatic, and my indy mechanic didn't even notice it. This is not noticeable whatsoever in any other driving condition over potholes or other bumps in the road...only when coming to a complete stop. Not a huge deal and not a deal-breaker, but the kit was expensive enough that anything much short of perfection is mildly annoying.

Drop: Here's where it gets interesting. Bilstein *suggests* (more on that later) a 30-50mm drop and in order to accomplish that range, and they recommend adjusting the shock collar to specs from a fixed point on the damper within a given 20mm range. One would assume that the upper end of this range would give the 30mm drop and the lower end of this range would give the 50mm drop...but that didn't happen. I initially set them up at the highest recommended level, assuming this would be around a 30mm (1") drop...but the front barely dropped at all while the rear did drop about 1 1/8". I then lowered the front all the way down as far as I could possibly get the collar on the threads of the shock body (obviously this was far below their recommended range) and only then got about 1.5" of drop. At that point, I was noticing much more harshness in the suspension and some mild clicks/clunks when I'd do a full lock turn at slow speeds so I raised it back up after just a few miles. I assumed I had done something wrong during the installation, so after several emails and phone calls to the techs at Bilstein, the answer I finally got back was:

"Bilstein does not give minimum and maximum drop ranges, it is more or less optimal performance range. These kits have been tested and built in Germany then re-tested on US spec models before they are cataloged. Do you have measurements of the vehicle prior to the install? My assumption would be that the kit is installed correctly if the dampening stages are working correctly. We recommend on all adjustable kits be corner balanced prior to alignment. The corner weights of the vehicle are not the same on all 4 corners which means it will require different preload per corner for the vehicle to sit correct and level. This will also allow the alignment tech to give it a once over to determine if everything has been installed correctly.

Not sure how to get past the part of you feeling our optimal performance range is not correct, again we have tested these on US spec chassis and populated our catalog notes to reflect our chassis measurements.

We have sold quite a few of these kits in the US and have had no issues to date."

I didn't bother responding once I got that answer b/c I got the sense they were blowing me off.

Long story short, after even more adjustment, where I ended up was lowering the front halfway between the lower end of their recommended range and the very bottom of the threads, and I left the rears at the upper limit of their recommended range. This ultimately gave me about a 1 1/8" drop overall, very even front-to-rear. It looks good, and, to be honest, I'm not really sure I'd even want to go any lower if it were possible, but I do feel somewhat let down that I didn't get the range I expected, even if I didn't plan to use it to the max.

So would I get them again? Yes. I absolutely wanted to keep the EDC functionality and have the ability to fine tune the ride height. Am I 100% satisfied? Not 100% but maybe 95%. The lack of *suggested* lowering is a bummer and the underdamping of the rear when coming to a full stop is mildly annoying, but not enough to give me any level of buyers remorse. I was so unhappy with the car before I installed them that I was considering selling it. But now it's just about right from both an aesthetic and performance standpoint, and with FBO/Stage 2, it's a freaking blast to drive. Had I not done the suspension, I don't know how the in the hell his car would handle that level of power so I'm very glad I went this route.

Hope this helps some of you, and I'd love to hear any feedback you may have!

P.S. The one thing I didn't do during install was loosen and retorque the preloaded rubber-steel interfaces so I had my indy shop do this later. Kind of annoying that this key piece of info was buried in the British version of Bilstein's website and not in the instruction manual nor even the American website. You'll see what I mean about halfway down this page:
Gonna have to add these to my list of "must buy." That fitment is great, and I also believe I had EDC. I have Xdrive and the fitment sucks.
2015 435i Xdrive (The Machine)
Stanced 8th Gen Honda Civic (The daily) Instagram: f32_phil