Confused about rear upper shock mounts

For an EDC equipped e92 m3 , when installing bilstein b16 pss10 coilovers , do you reuse the factory rear upper shock mount bushings which I think are 14mm from factory ?

Or do I have to get something like a power flex 12mm kit ?

I'm going through the install now and the video will be up on my YT channel in a couple of weeks.

You can run the factory rear shocks mounts and you don't "need" the Powerflex RSM for non EDC when installing on EDC cars.

My car is an EDC car and I have B16 PSS10. The EDC rear shock and Bilstein rear shock has a shaft (sleeve) ID of 12mm and an OD of 14mm, so OEM works perfectly.

With that said, I upgraded to the Powerflex Track (black) RSM and the sleeve ID is 12mm, but the sleeve OD is smaller than the OEM and Bilstein, probably 13mm. And the Powerflex RSM sleeve and bushing is a little taller/thicker which could be a problem when installing the B16 rear shock knob. But I'm working through it and will know more in a week.

Here's the video. Skip to 9:47 if you want to see what I'm talking about.

By the way, that Gemini A.I. is not 100% correct... The Bilstein sleeve ID is 12mm but the sleeve OD is 14mm which matches the OEM. I just installed the Bilstein using the OEM RSM and it fits perfectly.

The PowerFlex RSM sleeve is too tall (main issue) and the OD is too small (secondary issue) so it will not work with the Bilstein B16 PSS10.

SeanS54 wrote

Here's the video. Skip to 9:47 if you want to see what I'm talking about.

By the way, that Gemini A.I. is not 100% correct... The Bilstein sleeve ID is 12mm but the sleeve OD is 14mm which matches the OEM. I just installed the Bilstein using the OEM RSM and it fits perfectly.

The PowerFlex RSM sleeve is too tall (main issue) and the OD is too small (secondary issue) so it will not work with the Bilstein B16 PSS10.

Cheers for that . Any idea which shocks these will actually work with ? Shockworks? Bc racing? MCA? Kw v3? Ohlins?

sct911 wrote

Cheers for that . Any idea which shocks these will actually work with ? Shockworks? Bc racing? MCA? Kw v3? Ohlins?

Not sure, it all depends on the rear shock design. Bilstein's B16 PSS10 rear shock has a "sub assembly" with a couple of sleeves and nuts which makes the Powerflex RSM difficult to install unless you're willing to modify the upper Bilstein sleeve, which I don't recommend.

SeanS54 wrote

Not sure, it all depends on the rear shock design. Bilstein's B16 PSS10 rear shock has a "sub assembly" with a couple of sleeves and nuts which makes the Powerflex RSM difficult to install unless you're willing to modify the upper Bilstein sleeve, which I don't recommend.

technically if someone wants, they can grind down the "sub assembly" and make it fit ?

sct911 wrote

technically if someone wants, they can grind down the "sub assembly" and make it fit ?

Theoretically, you can probably grind down the upper Bilstein sleeve, but I don't recommend it. You'll potentially create other issues when reinstalling the adjustment knob.