[madriz]

Has anyone tried the powerflex rear inserts?
Are they worth it?

Is it better to put powerflex silentblocks instead of inserts?

[Jvac]

Hey man,
I haven't found anyone who has much to say about the inserts for the f30. I did find a few guys who did them on the 2 series bmws and were pretty happy. The inserts might offer about 30% of the benefit when compared to the solid subframe mounts, but the install is much faster and thus cheaper. With the inserts, you can 'lower' the subframe mounts one at a time and drop the insert in, then reattach and repeat for the other 3. To do the solid mounts, the entire subframe has to come out (several hours' labor) , and the existing bushings have to be pushed/cut/burned out before the new solid ones can go in. Unless you are doing the work yourself this will be a big ticket job, where the inserts can be fitted in an hour or two, I'm told.

[Jvac]

Also, I'm reading that once the rear end is stiffened so much, the front end will feel loose in comparison, so there's another thing to consider. Trying to keep the chassis balanced while modding should be a consideration.

[Lancelot]

Originally Posted by madriz

Has anyone tried the powerflex rear inserts?
Are they worth it?

Is it better to put powerflex silentblocks instead of inserts?

I have-
It's a very easy install compared to complete change of bushings, which is why I chose them.

I can't say it's night and day vs. stock, but more experienced drivers here could perhaps find it a more marked improvement.

[zole2112]

I installed the yellow rear subframe PolyFlex inserts but I did it along with the rear swaybar and coilovers so I can't give a review of just the inserts. I would do it again though, based on the design it will definitely stiffen up the bushings.