rear bushing and suspension upgrade recommendations

Hey everyone,

Currently on Ohlins R/T with GC camber plates up front.

I am currently planning on doing some suspension work:
1. SPL Tension Rods
2. Rear subframe bushings (solid Macht Schnell)
3. Rear diff bushings - Poly
4. SPL front and Rear end links


Lately when driving the car the rear end has felt unstable and floaty while turning or cornering. I am looking at refreshing and tightening it up as much as possible without making the car unbearable to drive on the street. My front end feels tight and has plenty of grip, but a bit different turning right or left (hoping end links fixes this).


With the subframe being dropped in the rear, I am thinking it’s a good time to refresh most of the bushings in that area. My question is - does anyone have a recommendation for good oem+ bushings for the rear arms that’s not fully solid but also better than the oem rubber?

Thanks in advance!

Just did a similar refresh on my E90. Overlap with your plan: solid subframe bushings, monoball bearings on the rear arms, adjustable toe links with eccentric lockouts, sway bars.

My read going in: rear wasn't floaty, it just wasn't communicating super well. Car felt planted but I couldn't always tell what the rear was doing, it was here and then it was there. Post-refresh, rear is maximally communicative and confidence-inspiring. Daily drive it, more taut but not harsh.

Meta on the NVH: the rear doesn't transmit NVH the way the front does, so arm and subframe bushings can go stiff without much cabin impact. Diff bushings are the exception because drivetrain whine has a direct path through them.

On diff bushings specifically: I'm running an aftermarket LSD and kept OE diff mounts. Stock diff + poly is probably OK. Even with OE mounts I hear some diff whine (although that's LSD more than bushings). Poly isn't fixing that and solid would make it worse. If an aftermarket LSD is in your future, go OE on the mounts now.

Nice! I think you will be happy with those. I have almost the exact same parts on my car. Solid subframe bushings and poly diff bushings. There is some whine, but while daily driving my car with stock exhaust it wasn't near enough to bother me. And girlfriend didn't notice it.

My understanding on the diff bushings from what I've read is: OEM vs. Poly you get a good increase in tightness/handling, with minimal NVH. Poly vs. solid diff bushings the handling difference is marginal, mostly increases noise. There's a lot more too it, that's just the general consensus I got summed up.

For the bushings, I think OEM vs aftermarket would depend on how much you track the car. But I am not super familiar with aftermarket options here. Remember: There is a reason street cars still use rubber suspension bushings!

Do this:

https://www.m3post.com/forums/showthread.php?t=1781245

The trailing arm monoball kit helped solve my bump steer.

https://www.fcpeuro.com/products/bmw-trailing-arm-spherical-bearing-set-fcp-euro-33326763092sm

Update for everyone:

I ended using that bimmerworld monoball kit, solid subframe, and poly diff bushings.

Rear end feels super planted and confidence inspiring, spent a weekend driving on in the smokies / tail of the dragon, feel pretty satisfied.

Car does whine now when I let off the gas, but it is pretty minor. Only time I felt it was too much was on the 8 hour drive back from tennessee.

Nice man! Sounds like a killer way to test out a fresh setup.

Interesting you get that much whine....but perhaps I just got used to it mine?