I was extremely fortunate to find a fantastic deal on a full Bilstein B12 Pro-Kit with Eibach springs as well as a full set of genuine BMW Performance Springs. I sold the Eibachs since I cannot run a drop that aggressive with my setup (1.2" drop from stock) and the roads here are such garbage I was worried about damaging something. So I went with the BMW Perf springs, T2 front, T3 rear.
Parts used:
I also purchased all new mounting hardware, but only ended up using some of it since the Bilstein kit came with some components and others were completely fine. I suggest doing the same, as you should replace whatever is damaged or old and you can always return what you don't use.
It took me a very long time to settle on this configuration but it seemed to offer the characteristics I was looking for:
- Slightly decreased ride height (.5" in this case)
- Stiffer all-around springs (about 35-40% stiffer)
- Better road feel
- Reduced body roll
- More planted rear in corners
First impressions:
I'm going to give my conclusion/first impression here, and then below you can find DIY info and an install video.
- Ride Height: I have only driven about 20 miles so far and I have not had the car aligned yet. The susepension has just settled and the drop is barely noticeable from the stock m-sport springs, and it's exactly where I want it to be. I expect it to settle a little more over the next month.
- Spring Rates: The BMW Performance springs are noticeably stiffer than the M-Sports, and I would say they feel like more than the advertised 34% stiffness increase. The ride is not at all jarring, and the Bilstein shocks soak up bumps much better than OEM.
- Road Feel: There is a noticeable increase in road feel but without an alignment there is also some oddities in the steering, this will after a trip to the shop this week.
- Body Roll: This is by far the most notable change, immediately you can tall that body roll and pitch has been decreased significantly. Braking and acceleration feels much more confident, there's no more nose diving on hard braking and the rear doesn't faff about under hard acceleration. Roll in corners has easily been reduced by 75%+ and the car feels much more responsive.
- Rear End: The back end of the car feels much more planted, especially over bumps in turns. I think adding a diff lockdown bracket in combination with this setup will make a world of difference from stock.
Overall Conclusion:
For the money, the B12 kit cannot be beat. However, I am also glad that I opted for the BMW Performance Springs as the drop with the Eibachs would have been way too extreme for local roads and my tire/wheel setup. The BMW Perf springs with the Bilstein shocks is a match made in heaven and the car feels much more confident overall. The car handles bumps and potholes well, with no increased stiffness that I can tell. The OEM shocks do not handle bumper roads well so this has been a great improvement. I have not found any downsides, and there's nothing I would do differently at this time. Some suggested camber plates, but with the BMW springs you do not need them. If you stick with the Eibachs, that is likely a different story. I am extremely satisfied and highly suggest this combination to anyone looking for a better-than-stock ride without breaking the $1k mark or jumping to coilovers.
Crappy cell-phone pics at my work garage until I can get some better ones:
20171211_095131 by
Matt Steele, on Flickr
20171211_095152 by
Matt Steele, on Flickr
20171211_095118 by
Matt Steele, on Flickr
20171211_095104 by
Matt Steele, on Flickr
The install:
I was nervous about the installation process because a few threads I had dug up made it seem like a very difficult task for the weekend garage warrior, and some suggested to just bring it to a shop as it took them 6+hrs to complete. Nevertheless, a good friend of mine helped me do some research and convinced me it was worth it trying to do this ourselves, and I'm very glad we did! We got it done in about 5 hours, and that included my friend having to drive around for 45mins for me to find a couple sockets we needed.
I won't go into too much detail simply because the DIY/How-To video we used from ECS Tuning covered nearly everything you'll need to know, I'll link that at the bottom of this post (
also click here for link) so it doesn't take up the whole screen.
Please note: You will NEED to get a 4-wheel alignment after this. Do not try to install a full suspension, especially one that lowers the car at all, and then drive normally. Let it settle for a few miles and then get it to an alignment shop.
Tools you'll need:
- 2x 18mm Sockets, at least one deep
- 2x 19mm Sockets
- 6 mm, 13mm, 15mm, 16mm, 17mm, 18mm, 19mm deep sockets and box wrenches
- 21mm thin-walled (or non-impact) socket for the top shock nut for Bilstein installs
- 22mm Socket
- Spring compressor kit (like this one, may not be needed if doing coilovers or pre-assembled struts).
- Extensions
- Schwaben Spindle Spreader
- Torque wrench
- Impact driver certainly helps, but is not required. We used an electric one my friend has.
- Metric allen wrench set
- Torx Set (for strut tower bars)
- Lots of penetrating oil
- Anti-seize and grease
- Needlenose pliers
- Various flathead screwdrivers
- Jackstands
- Jack (floor jack, not bottle or scissor type)
- Painters tape or masking tape, for protecting the paint on the front fenders
As I said before I used the linked video from ECS tuning and it did an incredible job of walking us through this project. I'll just add a few notes here on things that gave us trouble or things that are different from the e90 platform that they used in the video (everything is 99% the same, really).
e82 Platform Suspension Install Tips (video time-stamp links included):
[
Video] Have a friend help, even if you're a veteran. There's a few parts that are just damn near impossible to do solo, and it's always safer to work with a friend.
Get the car on 4 jackstands, set the e-brake and put the car in gear, lift the front first, then the back. The first setting on my jack stands was plenty of height to do everything we needed to do. If you're using a lift, you're a lucky SOB, ignore this tip.
[
Video] When doing the front shocks, make sure you take off the calipers and rotors and zip tie the calipers out of the way so there is no strain on the lines. This will make life much easier, especially when re-installing.
Loosen the control arms as little as possible to prevent too much adjustment to your alignment.
When pulling the front struts, do not push too hard on the suspension to get them out, you can damage components this way.
When removing the front struts, take a picture of the lines and wires so you know how they go back together, it's not always easy to remember!
USE THE SPRING COMPRESSORS if you need to dissemble the struts. They are under load and trying to remove the top nut can get you seriously injured.
[
Video] When lining up the lower control arm bolt near the hub for the rear suspension (on re-assembly), use a jack to help you out. The spring will be compressed and this will make things difficult. Take your time and be careful. Get that bolt in before doing the rear shock as you can insert the shock into the bottom, compress it down, and then guide it into the top mount.
[
Video] Removing the trunk liner is different from the e90, you will need to put the rear seats forward, remove some pins, and then wrestle each side completely out of the car. It's annoying, but you can do it.
Some other pics:
20171210_125659 by
Matt Steele, on Flickr
20171210_125730 by
Matt Steele, on Flickr
20171210_125742 by
Matt Steele, on Flickr
Update:
Got the car aligned yesterday, didn't take the pins out of the front shock mounts so front camber was limited but so far the car feels fantastic. Way more confident around corners than before, much better turn in, and way more responsive. The reduction in body roll is nothing short of astounding, it really feels like a sports car now and not some mushy sedan!
Spec sheet from the alignment is attached, and here's some bonus pics and the final product.
20171213_130751 by
Matt Steele, on Flickr
20171213_134325 by
Matt Steele, on Flickr
20171214_143432 by
Matt Steele, on Flickr