Are Current OE Rear Subframe Bushings Improved?

[jbfrancis3]

Since you mention upgrades, I'll volunteer the option I went with a set made by SuperPro. Everyone is partial to the products they install of course. I'm happy and everything feels solid without added NVH, so that's why I mention. I don't know of any other members running them.

Its amazing how many schools of thought there are around suitable replacements, varying from OEM-or-bust, to "upgrade" (define upgrade), to solid mounts.

https://superpro.com.au/find/superpro-subframe-mount-bush-kit-for-a-superpro-suspension-parts-and-poly-bushings-for-bmw-3-1998-2006-e46-/productnr-SPF4328K/cid-999500345/vid-

https://www.urotuning.com/products/superpro-rear-subframe-mount-bushings-bmw-e46-e89-z-spf4328k?variant=8384778797111#collapse-tab4

[oceansize]

I went from fresh OE to Poly to Solid (within 7000 miles). I won't be going back to either OE or Poly. Assuming you are reinforced then the only concern would be the NVH which is of no consequence. I think there are enough people running solid RTABs and subframe bushings that if NVH was an issue the choir would have already sung its chorus.

[old///MFanatic]

Thanks, yeah not sold on the solid or the Delrin versions quite yet. Not for street. I mean there’s a good deal of engineering that went into these factory mounts. The front two are different designs L and R from each other. Both are different from the rears. You can see the differences quickly. All these poly are the same mushroom design(mostly to hold in place), nothing engineered about their functioning really.

And looking in the ETK all the factory M3 subframe bushings were revised in 3/06. So one could expect they’re even better. Unsure how many made it onto the late M3s or if they just had enough old stock.
As we know any new bushing, be it poly or stock is going to feel better than worn bushings.
Hoping to hear some thoughts or feedback from use.

[Slideways]

How about solid bushings? It's what all the cool kids are doing

Poly is the only in-between for stock and solid.

[old///MFanatic]

Going to change out my four RACP bushings. I’ve used poly in the past (over the decades) on several other components and learned it’s not always the best. In fact it’s mostly a scam in design over stock in some cases. Also it can deform and oval out, not rebounding well after deflection.
Anyhow, question is are the current stock subframe bushings improved over the years. I noticed they look different on the bottom/top. Although it may just be a shipping protection/installation guide, the green area looks somewhat changed too.

I’d like to upgrade on them, but everything out seems to be basic two-piece split replacements and nothing in a firmer stock design firmer durometer rubber.