E30 to E34 suspension

I have been getting a lot of hits to my blog from people searching for ways to upgrade their E30 suspension to E34 suspension. My guess would be to go from 4 lug to 5 lug. I haven't heard anything about doing this, but since I have access to the parts, I thought I would investigate. I went out in the yard and grabbed an E30 rear control arm and an E34 525i rear control arm. Just by laying them side by side I can say that if it is possible to use E34 rear suspension it would require some heavy mods.


For starters the E34 is 2 inches wider that the E30. Also, I don't know if you can see it, the E34 shock mount is on the top of the control arm. The E30 shock mount is on the bottom of the arm.

Finally, E34's use coil over shocks where as E30's use springs separate from the shock, so there is no spring perch on the arm. I suppose you could us a coil over set-up on your E30, but for the sake of argument, the perch is missing from the E34 arm.

As for the front struts, I don't think E34is going to work because of the different control arm set-up.





If any one has any more info on doing an E30/E34 swap, feel free to leave me a comment.