ECUs and engine swaps

[Alex7747]

Hello DSMtuners,

I haven't been on here in a very long time. Ever since i got my BMW i stopped looking for a DSM and was really just focused on school.

Anyway, i couldn't resist the DSM bug any longer and bought a 6-bolt 4g63t short block with a 1g head. and i want to start a project that I've really been considering lately, and that is an e46 BMW with a 4g63t and w58 transmission (t56 if i find one for a good price). I will be buying another e46, and my 325xi will remain my daily.

My main concerns on this kind of project is all of the wiring involved.

For my wiring i was thinking of doing all aftermarket gauges (i don't care about having a stock gauge cluster, because the car will mainly be used for weekend cruise nights or the occasional track day.

So my Question is this:
Is it possible to wire up the ecu to a direct power switch? And also how much of the wiring harness would i need to run DSMlink?

 

[Miasma]

Thats awesome, reminds me a friend who put a nissan jz motor is his BMW. His wiring was a nightmare , but you can do it. He just didn't take anytime to tuck his wires.

Hope it comes along great.

 

[Bud92gsx]

What do you mean by wiring the ecu to a powered circut?

You could do it the easy way and do a battery shut off switch..But i'm really not sure i'm understanding the question at hand.

 

[Alex7747]

Thanks for the replies. Im basically asking if it would at all be possible to hook up a direct current from the battery to the ECU, but i would use a switch to turn the ecu on and off (along with a fuse).

The reason I want to do this is because i don't even think it would be possible to integrate the DSM harness into a BMW harness (seem way too complex).

This is my only concern with the swap and if it is possible i will be going ahead with it and buying the BMW somewhere in march or so and doing it.

I have been looking at some DSM pinouts and most say the pins 25, 12, 13 i believe are all the power wires for the ECU. Is this all that would be needed??

Edit: i want to use a 2ga engine harness.

 

[Alex7747]

Anyone?

 

[HIGHPSI4]

You are getting close. You will need to figure all circuit wires for both cars and then splice the two wiring harnesses together unless you want to move all the dsm stuff to the other car. So, yes, those two wires will get power from the battery source.

 

[Alex7747]

You are getting close. You will need to figure all circuit wires for both cars and then splice the two wiring harnesses together unless you want to move all the dsm stuff to the other car. So, yes, those two wires will get power from the battery source.

Once the ECU has power it should run the engine, correct?