BMW M70 project
Posted: Sat Sep 18, 2021 2:26 pm
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?
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?
