[help needed] BMW M70 project

[kartsan]

Hello all,

My history:
I used to have a BMW E32 750iL project car but I sold it and in the same mess I was blessed with one (rebuilt by myself) M70 engine which has been sitting in the corner of my garage for a couple of years. I've been playing with an idea of using an aftermarket ECU and was looking for a good ECU for my project but since I always like doing things in the hard way, the ECU's that meet my requirements are rare and expensive. Finally I found out about Proteus ECU which looks promising.

Plan:
-I want to throw away the distributors (I hate them) and introduce sequential ignition. I'm planning on using e.g. M50 coils with ignitors.
-Sequential injection because I want do some injection research
-Use stock EML to control the ETB's. Gain: You get idle control and cruise. Problem: Stock ETB control is slow. Fix: Use Wokke EML chip.
-Use M73 cam position sensor for sequentials

Previously, I planned adding a cam trigger wheel in the place of the distributor rotor but the I realised that M73 is using exactly the same cam sprockets so I thought why not using that with an M73 part that holds the cam sensor? There is an additional hole in M73 cam but that is merely for positioning of the trigger wheel.

In theory, these parts should fit but I have not tried that yet. If not, I probably need to either fit that extra trigger wheel or just use batched injection and wasted spark.

There are a couple of things that are still open:

1. EML synchronises the two ETB's from the injection timing signals from the ECU's. I'm guessing each ECU is using its own MAF to choose injection from the map. With Proteus, EML should be satisfied somehow by sending the same kind of a signal although no synchronisation is probably(?) required.

2. If I use one MAP sensor, shouldn't there be a pipe between the intake manifolds to even the intake pressures? Otherwise, mapping is right only in that manifold side where I have the MAP sensor and the other side is getting wrong input. In the perfect world, this never happens but in the real world there may be leaks in the other manifold leading to problems. Use a MAP sensor for each manifold?

3. EML informs the ECU's with two signal wires: idle and kick down. When engine is idling, idle is up and when kick down is pressed, kick down is up. I think there are three main maps in the ECU's: idle, normal and kick down. A map is chosen according to these EML signals. I wonder if the same is possible to implement in Proteus? Or just ignore these inputs?

[AndreyB]

With Proteus we prefer to throw EML away. What is EML by the way just to make sure we are on the same page?

Yes see Lambo replica and their pipe of exactly that nature

See above. rusEFI community has extremely limited resources to think about EML. See https://github.com/rusefi/rusefi/wiki/HOWTO-M73-v12-on-Proteus on the ETBs we love to use on M70//M73.

[kartsan]

With Proteus we prefer to throw EML away. What is EML by the way just to make sure we are on the same page?

Yes see Lambo replica and their pipe of exactly that nature

See above. rusEFI community has extremely limited resources to think about EML. See https://github.com/rusefi/rusefi/wiki/HOWTO-M73-v12-on-Proteus on the ETBs we love to use on M70//M73.

Hello AndreyB and thanks a lot for your answer!

This document explains quite well what EML is about: https://www.meeknet.co.uk/E32/EML-BMW.pdf

My car is E32 1992 so we talk about Bosch EML 1.7 system. As you can see in the document, quite a lot of features are controlled by EML, for example A/C (EML turns up rpm when used), cruise, etc. DME's are slaves for EML. As my car already uses EML, I think it is possible to use that. However, I understand that if you drop M70 or M73 on a non-BMW, it is better use rusefi to control ETB's.

[AndreyB]

What i am trying to clarify is the fact that you are on your own for rusEFI/EML integration.

[mck1117]

quite a lot of features are controlled by EML, for example A/C (EML turns up rpm when used), cruise, etc. DME's are slaves for EML. As my car already uses EML, I think it is possible to use that. However, I understand that if you drop M70 or M73 on a non-BMW, it is better use rusefi to control ETB's.

rusEFI already supports all of those functions with the electronic throttle, except for cruise control. Trying to integrate the EML system with rusEFI is going to be more hassle than it's worth.

[AndreyB]

Any progress?