Originally Posted by W Cole
I have been meaning to start a similar thread as going supercharged has recently peaked my interest.
My main concern is with the main bearings. I know these engines have main bearing issues at stock power levels and I would think these problems would only be exacerbated by an additional 50% HP.
I have done a ton of research on the main bearing issues and many say the issues were unique to the 2008s. However, I have also read that there were no part number changes and that the bearing tolerances did not change from 2008 so I'm not sure why these issues would be unique to the 2008s other than they have the highest miles.
Would it be recommended to inspect and replace/upgrade the main bearings before going forced induction? I am assuming this would be a ton of labor since the engine would need to be dropped?
From ESS's website regarding the 625+ kits:
"...on 2007 and 2008MY cars we recommend upgrading the rod bearings to latest BMW spec before installing this kit."