Rear end update!
Alright, time to match the rear to the front with the following:
- TRW Guide rods
- E92 / E84 rear chassis strut brace
- Whiteline subframe bushings (wagon specific install notes below)
Guide Rods
These are pretty well covered on E90 post. Known to enhance braking and acceleration feel thanks to replacing a bushing with a bearing. The only negative I'm aware of is the fact that they effectively lower your spring rate slightly due to bushing wind up. Thanks to @freedomfries for the tips!
Install notes:
- you don’t have to disconnect the sway bar if you Jack the hub to ride height. Found out this after I unbolted the sway, of course :-)
- E92 / E84 rear chassis strut brace
$46 Pick N Pull find with all hardware Woot! I considered the M3 version of this but it was 2-3x the cost, and this accomplishes the same thing, plus this is welded and uses 4 pinned connections on the chassis connection front versus 2 for the M3 brace. Also, some chassis (e9x variants) have been produced with only the two middle threads on each side, which means you'll need to know if your car has all 4 threaded to utilize all bolt holes. Of course, you could just use 2 bolt holes with the 4-hole plate, but since mine came with all 4 threaded it made the choice easy.
Scarcity; No one is looking for them so they're cheap and plentiful. Easy decision.
Impressions - this one is hard to say as I did all three together. Certainly, I am feeling road sensations through the seat bottom that were never there. In a good way - finally, the rear end motions are communicated to the driver.
What I mentioned above about the stock locations in some cars not being threaded. Thanks for the info @soravia.
For E91 shim up the stock wagon brace with hardened washers at the red circles. Also, I would like to weld this structure together to make one big brace with some connectors shown with red lines. The F80 cars have a similar webbing that people are welding as such. Anyway, just a thought
Whiteline subframe bushing - wagon specific install
These have been on my shelf for 4 years. And now they are alive and well! The wagon specific portion of this applies to the rear bushing as it is different than the M3 or the regular e90. Apparently, the 335d bushing is the same as thee91, but I can’t confirm. In essence, the rear upper portion of the bushing is different enough that the standard Whiteline doesn’t fit in its provided form. I hacked it up and used the corners. See pic below.
Other info:
https://www.bimmerworld.com/Suspensi...Track-Kit.html
Powerflex makes a wagon specific kit, but for the extra $150 it would have cost I would prefer to go whole-hog with solid mounts. These cost me peanuts on here and do 90% the same thing. I'd argue likely 100%, but we know how arguments get started!
Impressions - the suspension finally is allowed to work as it should. So happy that soggy, saggy rear end feeling is gone. This install definitely eliminates the 3rd unnecessary oscillation you get on the freeway, etc. pitch and sway is nicely mitigated. Also, gives more feel for the hooligans! Previously, I never pushed this car outside an auto-x course bc the damned thing just felt scary and unpredictable. Now, tale-our wet pavement antics are finally a thing.
Here you can see (maybe?) in the yellow circle the slivers of Whiteline top bushing I cut to fit.
