[DominicB]

Would it be possible to configure speeduino in sequential mode so that a separate VR table can be created for each cylinder and the injection timing (start, middle or end) can also be defined individually for each cylinder?
Because of the intake tract design, some engines require quite different injection quantities for the respective cylinders.

[PSIG]

Welcome, DominicB. Speeduino has Sequential fuel trim for this purpose. While equally important (or more important in some cases, e.g., power adders or extreme economy), Individual Cylinder Ignition Trim (ICIT) has not yet been implemented, although I believe it was near-ready back when SFT was implemented.

Just to be clear, SFT uses the primary VE table, but (assuming it's a differential flow issue fuel or air) modifies it as a table for each cylinder, creating the effect you appear to seek. Find it in TunerStudio under Tuning > Sequential fuel trim.

As a trivia note, OEMs use sequential and SFT primarily for meeting emissions requirements, whereas performance and racing applications use sequential in order to access per-cylinder trims like this. Two very different reasons, environments and goals for the use of "sequential", and applied very differently as well.

[DominicB]

Thanks for your reply PSIG.
Good news regarding the sequential fuel trim, the behavior of these engines regarding the different mixture ratios should be manageable in that way. There are significant differences between cylinders of up to 0.3 Lambda.

The second problem is that you have to inject the fuel at a different timing, so for example the start of injection for cylinders 1 and 4 has to start at 40° after TDC, while cylinders 2 and 3 needs to start at 0° after TDC. would this be possible?

[PSIG]

The ability to trim the fuel for each cylinder generally removes the need to also alter the injection timing. Yours could be a special case, but it's unlikely, so I would simply test it.

Earlier versions had the ability to change injection point per-cylinder, but that feature has been removed as unnecessary with other adjustments. I'd try it first and go from there.

There are other possible workarounds for injection timing that are available that I won't go into at this point, until you verify with real-world run-tests what you need, and some basis for why it may be necessary for you. What specific issue you are solving is an important bit of info to finding best solutions.