[ervgotti01]

Originally Posted by SteveAZ

So, I really don't want to debate any of this on this board.

The problem I had with this thread is that the OP gives what appears as a very biased and inaccurate description of the details. By that I mean...

He says he was unable to reproduce his failures without a tune. He takes the car in, has to have 4 injectors that "failed" replaced...now he doesn't run E85, all his problems are solved, and he is making this proclamation.

Now, as hard as I may try, I too am obviously biased.

So my only message here is that most people usually go searching for data that supports their original position. If that's what you do on this topic, you're going to find it no matter which side of the field you're on. Think critically, do your own homework, and draw your own conclusions.

To get anybody interested started in their research, here is an interesting conversation that took place between a member on another board and one of the engineers responsible for the development of our fueling system. I can't post a link to the source, but I'm sure if you copy and paste a line from what I've posted and do a Google search with it, you can find it for yourselves.

Enjoy....

Does the N54B30 use homogenous or stratified charge under high load ?
- The engine was developed to run in homogenous mode. The N53 engine was to run in a stratified mode. Although the engine is capable of running in stratified mode, it currently does not.
It uses an outward opening injector.

Have you experience with this engine and E85 fuel or do you have any thought on it ? Can e.g. the injectors handle alcohol ?
We have a lot of experience with E85. Currently, we have an issue that if the injector is hotter than 100 Celsius, we are seeing melting of the fuel filter in the injectors. As long as the temperature of the injector stays under the 100 Celsius, this engine is perferctly capable to run E85. As a matter of fact, it will run E100 without any problem under cold conditions. There is no need to preheat the fuel.
We are investigating the filter issue, and we hope to have a solution next year. Whether or not we will create injectors for this engine, depends on the market (read: BMW).
It is not possible to replace this filter yourself; you cannot open the injector to get to that part.

Is the HPFP pressure of 90 bar constant or is it controlled by the MSD module ?
It is constant but indeed controlled by the module. The engine has been tested to up to 200 bar. If you keep the HPFP pump below that number, you could inject a lot more fuel. The relation between the amount of fuel sprayed and the pressure is not a linear relation but a Bernulli equation.

In our earlier conversion, you mentioned that under high load the TI is about 2 ms ? Correct ?
Yes maximum is 2 ms. Notice that the engine runs under homogenous mode and that means that the injection start in the intake phase. With this engine, it is no problem to keep injection into the compression phase, but not too long; it would be bad for emission. However, if the pressure of the HPFP is increased, this may not be needed.

The injectors have a maximum of 40 mg/ms spray at 200 bar. This is an increadible amount of fuel, much much more than any solenoid injector. It is this high, because when we designed the application, BMW insisted that the engine must be able - in limp mode - to only use the LPFP pressure, which is 5 bar, and still drive the vehicle at 170 km/h.


If correct, do you agree then that considering the ti in the compression phase, we can get it up to 4 ms for 7000 rpm ? Can we use the full compression phase ?

You would have to calculate it, but yes, there is extra time at mentioned before.
The injector can inject a lot of fuel into the cylinder. When increasing the injection time, and also when injecting in the compression phase, look out for cylinder wall wetting. This is dangerous. It would wash away the oil on the walls, causing wear. One way to check for wall wetting is to check the engine oil if it has fuel in it. Another way would be to check if the vapor of the exhaust gas recirculation (EGR) and see if there's fuel vapor.
The risk of wall wetting may be reduced by running higher boost, as it affects air flow inside the cylinder.
Running the HPFP at higher pressure may increase the risk again.

You said we should tune the TI duration of the ignition pulse. Can we also tune with the MSD via a reflesh when the ignition time starts ?
There is indeed a calculated ignitition start time in the MSD. It is not a map, but i'm not sure.

How does the ECU measure a knocking problem ? Does it use voltage ? Does it do it for all 6 cilinders individual ?
Each piezo injector has a knocking sensor. It measures vibration. By looking at certain frequencies, the knocking signal is sent.

De community is desperate to lean more about the MSD80. We would love to have information that can help us reflesh the unit to tune to engine for 600 PS. Can you help ? Can you direct us to a colleague (do you have a name ?) This is vital for my own project too !
I don't know about the MSD80. I'm an injection / fuel system engineer. I will talk to some colleagues and see if i can help you with anything. We have to make sure we're not infringing any copyrights and i think BMW owns the rights to the information on the MSD.


Can we buy this information ? Who should I talk to to ?
there may be a legal way to buy this information, i will talk to some colleagues and mail you back.


All of us want to invite you to join our forum N54tech.com. An engineer like you would be incredible value to the forum, may I mail you an invite to join ? It’s free of course !
Thank you for the invitation. I will think about it. I have to be careful not to share information that my company doesn't want us to share.

Very useful information right here, and I've read and followed that thread for a bit. But the part in bold straight up proves my point. I had injectors that failed, not the HPFP nor LPFP...injectors. 100 Celsius equals 212 Fahrenheit. Hell our oil runs hotter than that and you'd be naive to think that the injectors aren't reaching that temperature.

If you've been following the N54 platform as long as I have (Since 08) you would have seen the numerous batches of injectors BMW kept throwing at the problem as they were having injectors fail even before people were running E85. The inconsistencies with what batches were or were not failing means like I said you can have a different batch of injectors compared to someone else with N54. Some of the newer batches might have a better designed filter, but you would not know what batch you're running unless you pulled the numbers off your injectors.

Hence my original intent was to say if you can't afford to replace multiple injectors, you might not want to mess with E85. Which is so funny because as soon as someone creates a "I'm out of warranty thread help" you people are so quick to point out "you gotta pay to play".

As far as the dealership issue, I don't understand how you can't comprehend this? So I'll try to explain it again as simple as I can:

1. Most if not all Dealerships will not perform any warranty work unless there's an engine code. This is what they use to justify to BMW the work performed.

2. When my injectors went, it would only throw multiple misfire codes under tune, even the mildest tune ie sport and drive maps on Cobb and I had stopped running E85 by then.

3. It would not I repeat would not throw those codes on the stock tune no matter how hard I pushed it.

4. With the Cobb AP when you flash the car back to stock, it automatically erases all codes stored within the DME. There is no getting around this.

5. Hence my dilemma, I couldn't get warranty work done without codes but I couldn't keep the codes stored unless I kept the tune on.

It's so funny to me how there are multiple threads on multiple forums asking if people have had any trouble running E85, but as soon as someone says something everyone is quick to jump their bones. Trust me I was on the other side of the fence and loved running E85, but now I would only run it for track or race purposes.