ericjon262 wrote: ↑Thu Feb 17, 2022 11:51 pm most EFI applications I have used in the past (granted, use was limited) performed calculations similar to what was described by not including target AFR, having the VE table control fuel, so I stuck with that, or at least I think that was my mindset at the time. include target AFR sounds simpler by the way you describe it.
Right, it's a matter of preference, though includeAFRtarget seems simpler to me.ericjon262 wrote: ↑Thu Feb 17, 2022 11:51 pm I haven't seen a VE table that looks like your's before, but most were using different algorithms for fuel control, so they would look differently. I'd imagine enabling incorporate AFRTarget makes the majority of that difference.
If I weren't running includeAFRtarget, then my "VE" (well, not strictly volumetric efficiency) table values would be greater in the parts of the table where I had a desired mixture richer than stoichiometric.
Whatever way works for you. I like the autotune in TS to rapidly iterate in the beginning, and to use MLV later to fine-tune using a bunch of data. For the last VE fine-tuning iteration I did, I drove around for about a month, datalogging on the SD card (no laptop in the car). I then ran MLV on the month's worth of datalogs.ericjon262 wrote: ↑Thu Feb 17, 2022 11:51 pm I've actually been using the VE analyze feature, in MLV, but not the autotune as much.
Hmm, so it looks like your injectors are firing twice for every 4-stroke cycle.ericjon262 wrote: ↑Thu Feb 17, 2022 11:51 pm currently MS3 doesn't support my crank and cam position sensor arrangement for actual sequential injection.
If you could fire the injectors once for every 4-stroke cycle, then the same fuel could be delivered with a single, longer pulse. You would only have one dead time error per cycle, not two.
Even without the full sequential support in MS3, you can turn off sequential and run batch fire (2 squirts alternating).
With 2 squirts alternating (one bank squirted, then the other bank is squirted), you'll have the same pulse width as with a full sequential setup.
That test data will only be applicable if you duplicate their test condition in your car.The Dark Side of Will wrote: ↑Fri Feb 18, 2022 8:27 am What OE application were they used in? You may be able to find OE injector table data for them... that you know is backed up by a lot of test time.
As much as dead time depends on the injector, it also depends on fuel pressure, and the flyback voltage (likely to vary between MS and OE test setup/ECU) of your ECU.
I think that the in-car method could be quite sufficient.ericjon262 wrote: ↑Fri Feb 18, 2022 9:23 am I'm not aware of them being used in an OE application, I have thought about getting another set and having them flowed and getting as much data as I can from a fuel injector service, I'm not sure how necessary that is though.
With the car running, toggle between Batch fire (injector firing once per cycle) and Semi-sequential (injector firing twice per cycle) : If the ECU is exactly compensating the dead time, then total fuel delivery will be the same regardless of whether it is delivered in one or two shots per cycle. Therefore, measured AFR won't change as you toggle the setting.
Once you have found the dead time that keeps AFR constant, confirm by commanding a 10% richer mixture (either by the VE table, or AFR table if you run includeAFRtarget). If the measured AFR is 10% richer, then you're golden. After all, the goal of getting the correct dead times is that the ECU can adjust the mixture as desired, and obtain the desired results.
You'll want to repeat this test with the alternator disconnected, so that the dead time is calibrated at two voltage points (running voltage and battery voltage).
Since you have a pretty long duration camshaft, you may want to perform the dead time testing/tuning while revving the engine to 2k-3k, so you don't get into fuel bypassing the combustion chamber during the overlap period at idle speed.
This method has worked for me (at idle), but using a milder camshaft than yours.