Question on ECU and swap.

[Notsafe335]

I've been searching/researching for hours on swaps with m20s for my daily. Correct me if I'm wrong, but all 325i parts on a 325e car with double valve springs added and I should be pretty good to go? I found an ECU, it's a Motronic with part numbers 0 261 200 525 and 1730527 001 810. Would this work in my 87 325e manual. Stated to have came out of a auto convertible car. Also, if I snatch up an i head, it should have the double valve springs no? And I can also swap the cam over. Thanks for correcting my ignorance.

[MR 325]

Don't bother swapping anything in to the Eta head. Swap the i head on along with the rest of the i top end parts. Yes the i head (885 head) will have the dual valve springs. For the ECU the 525 ECU will work just fine.

[TurboJake]

Yes and no. The critical part is the head. If that head isn't an 885, you're wasting your time, and very well could kiss your valves with the pistons. The double springs will not swap into the 200 ETA head, and along with that the 885 cam will not swap into the 200 head.

[Notsafe335]

Thanks fellas.

Here's my concern though, everyone(in the sticky I read) has stated that the 885 head is wasted on stock ETA pistons due to compression and the flat top pistons. I know SETA pistons are the ticket, however I really didn't want to pull the motor at this time. I guess two people saying otherwise is enough for me.

I guess that confirms all my suspicions. I've seen dyno plots from 885 heads on ETA bottoms make 130 to 150 wheel depending on bolt ons and engine health, which is what I want to make. Any recent feedback/insight? I know this swap has been done for the past 10+ years but I know there's been more people doing it recently. Thanks!