Motronic Conversion ECU covering experiment

x_atlas0

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Hello, everyone.

I'm mostly done with my Motronic conversion, and am attempting to figure out where to place the ECU without drilling a hole in the firewall. I think I have found an OEM solution: the Mini.

My dad picked up a fully spec-ed out JCW Mini Cooper S a few weeks ago (great car so far, by the by) and I noticed that the ECU is contained in a seperate, plastic compartment next to the airbox. I hunted around on Realoem and found the part:
http://www.realoem.com/bmw/showparts.do?model=RE33&mospid=48021&btnr=13_0979&hg=13&fg=20

On the drawing, it is part #1, along with the cover, part #4. I ordered the parts and picked them up earlier last week. The Motronic ECU is perhaps 1/8" too thick to fit without modification, so I'll be working on either enlarging the sleeve or reducing the ECU thickness.

I'll post more as I make progress. I figured you all might want to know, as drilling seems rather destructive.
 

Philip Slate

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E34 M5s (and maybe others) had ECUs compartmentalized in the engine bay and also had a thermo switched fan to help prevent over heating of the unit. You might want to consider a way to get air flow to your unit, so to speak, also.
 

x_atlas0

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E34 M5s (and maybe others) had ECUs compartmentalized in the engine bay and also had a thermo switched fan to help prevent over heating of the unit. You might want to consider a way to get air flow to your unit, so to speak, also.

The airbox actually has vents that allow air to come in and cool the unit, so that is taken care of. It does make it less than watertight, however. I'm thinking that the minimal water won't damage the ECU, though.
 

Malc

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M535 has it bolted inside up under the dash, doesn't seem to get that warm
Water and electronics don't mix very well so be careful

Like a Csi
You could put it under the rear seats, run the harness from there, inside the front chassis leg, and come out from there in the engine bay
Long harness but that's how it was done
Malc
 
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