[Rednaxs60]

Road trials continuing. Interesting observations as well. General engine operating at 80 to 95 kPa, regardless of RPM range with one caveat. MAP readings 80 kPa and above have a TPS opening greater than 10%. Under a TPS of 10% operate in the 55 to 80 kPa range. Doing "seat of the pants" tuning at this time. When I "feel", or hear an engine operating issue, I maintain that speed, RPM and kPa range to make sure I have the area identified. Once this is done I stop, bring up the VE table, adjust the cell values affected, up or down, and ride again, repeat as necessary. Not too scientific, but working. Will identify the areas I have just adjusted for timing adjustments.

[Rednaxs60]

We don't need 123x123 cell tables, as we have interpolation and can move our cell spacing. A huge advantage over some other systems. Table spacing is a valuable tool. Move 'em where you need 'em:

Have done this for the RPM axis and it is working well:

VE Table RPM Axis Values.jpg (91.38 KiB) Viewed 770 times

Gained one RPM column in the RPM range normally operated in. Going to do this with the "Y" load axis. I will be gaining two rows in the area the engine is normally operated. Don't need the 26/30 kPa range, never going to operate in this region. If for some reason the kPa does dip down to these values, expect the ECU will use the last value until the engine recovers, something like the baro reading without a baro sensor. This is the new "Y"load axis values I will be using:

Table Load Values.jpg (65.66 KiB) Viewed 770 times

Now to do up a new tune for road trials. Maybe change the "x6" values to "x5" values, clean up the tables.

[PSIG]

Weird, I posted but it is not showing. Anyway, we want to capture the entire range, and just space wider where it can interpolate. So if we will hit 20 kPa in deceleration, we want to include that, but perhaps space the next header to 40 or 45 kPa, so it interpolates 30 kPa when it transitions. This is better than forcing 36 kPa fueling on a 20 kPa decel. See what I mean? Capture the full range expected, and space appropriately.

[Rednaxs60]

Weird is correct. saw your post and understand. Where it went nobody knows.

[Rednaxs60]

I will be trialing Alpha-n (A-N) fuelling profile in the near future. These are my thoughts on the direction of my project and not to be inferred as a way ahead for anyone else.

I have mentioned that Honda uses both SD and A-N fuelling profile in the 1982/1983 Turbo motorcycles and 1985/1986 GW 1200 models. I have experienced having a bad TPS on the '85 GL1200 model. I had a new TPS installed on my '85 GL1200 FI model - QA/QC of these components is not that good, new is no indication of the quality of the TPS sensor. I had engine operation issues in the 2500 and 3500 RPM, the RPM range that all GL1200 GWs cruise in. Below 2500 RPM, and above 3500 RPM the engine performance was good, but had other consequences - you are either going too slow or too fast for the posted speed limits. My issue occurred on a cross Canada trip. Changed the faulty TPS part way across, and all issues went away.

Having mentioned the above history, I have been thinking of the engine tune. Nothing I do has brought the engine tune into focus, and no, I'm not bouncing all over the place. The incident above indicates to me that Honda probably recognized this issue with the ECU engine fuelling programming - SD MAP (load) always near atmospheric at cruise, and decided that A-N had to be implemented in the normal cruising. RPM range(s). Information on the Honda CFI system is sketchy to non-existent.

The OEM CFI system does use the SD fuelling profile in the lower RPM ranges, know this because the OEM CFI system uses two, not just one, pressure balance (PB) sensors (MAP equivalent) that max out at approximately 2500 RPM, but with the ability to use the tuning software and monitor the MAP sensor reading, the MAP reading is in the high engine load region after the TPS passes the 10% open range.

A blended fuelling profile may be in order incorporating SD in the lower engine RPM ranges as part of the natural evolution of this Speeduino ECU install.

The OEM Service Supplement Manual further corroborates the fuelling profiles. Normal engine operation uses an Ne-Pb map for engine fuelling and ignition. Ne for Alpha-n, and Pb for SD. When a PB sensor is faulty/fails, the CFI ECU fuelling/ignition defaults to the Ne-Oth map.

The service manual for the CX500/CX650 CFI turbo models supports this premise as well. In this manual, Honda mentions a TPS delta value (not specified) that the engine fuelling profile switches between SD and A-N fuelling profiles.

Looked on-line and most information indicates that the A-N fuelling profile is widely used in motorcycles, and in the piggyback modules that one can find to use.

I have looked at many forum posts as to what is needed, and know that a separate barometric sensor is required for A-N. Have noticed that there appears to be reference to a quasi-Alpha-n fuelling profile, or a "true" A-N fuelling profile. A "true" A-N apparently needs a barometric sensor, and as such it will be done sooner than later.

Will report on the road trials.

The best aspect of the Speeduino ECU is the ability to try different attributes and if it doesn't work, you can always revert back to the tune you replaced. Enough of a "rant", time to get back to the grind.

[PSIG]

Always an adventure. Here is an example VE Table for ITBs, showing heavy top-loading of cells, with more than half of them above 80kPa and spaced 2 kPa apart for cruise resolution. You can literally jump from 16:1 cruise to 13:1 power in 2 kPa, if that suits your tuning and conditions. Just throwing some ideas out for you.



If going for a comparison of SD versus AN versus blended, I'd give the tuning a fair shake at optimization so the comparisons are reasonably valid. To do this, spot tuning is needed so it's optimal, not just OK. For example; what is the optimal cruise AFR you found at 3000 rpm, by tuning to just short of surge? What was the perfect warm-idle AFR found by minimum MAP, etc? Did you reconfigure your table headers and blend those spots together for a representative SD table for comparison?

[Rednaxs60]

Last major (?) addition, Baro sensor. Been testing the MAP sensors on hand. The newer model 079800 won't cooperate so I connected the an OEM PB sensor and it worked. Hadn't noticed before, but the OEM PB sensors are ND 079800 sensors. This should allow me to connect this OEM sensor and configure it as a 079800 Baro sensor. Have a spare now. Intend to connect this sensor signal to IDC pin 47, jumper to A15 and configure TS Baro pin to A15. Will pick up the 5V and ground from the existing sensor power/ground circuit, and run a signal wire into the enclosure connector and out to the IDC connector.

Question, is a resistor, 470 ohm, still required with this sensor between sensor and pin A15, or can I hard wire the circuit without one?

Pics:

PB Sensor 1.JPG (73.01 KiB) Viewed 689 times

PB Sensor 2.JPG (89.56 KiB) Viewed 689 times

@PSIG - read your post #672823, makes sense now, more radical than I would have thought. Deserves a good "shake", as you mention. As I mention above, can't hurt, if it doesn't "pan out" revert back to a tune that does. The addition of the Baro sensor completes the basic install and permits a host of possibilities.

When I road test, have TS on the tablet, and have the VE table showing. When I feel an engine performance issue, keeping at the same RPM and gear, look at the VE cells being affected and these are the cell(s) I adjust when I stop, repeat as required.

Have some other settings to tweak regarding fuelling, but will give your recommendation a shot. Have to get at the timing as well.

[Rednaxs60]

Have a new engine tune to use based on @PSIG recommendation. Set it up for idle in the garage. Have to get on the road to adjust. Going to give it a good trial for later comparison.

Question, have been thinking and looking at the AFR/lambda meters. Best AFR/lambda has to be determined. Is it possible that the generic settings are just this, an estimate. If so, the AFR/lambda meter readings may need significant adjustments. Consistency is what I'm looking for in any gauge. If the values are consistent, can fluxuate, but I'm generally concerned only if there is a wide swing in the meter values I see.

[JHolland]

The newer model 079800 won't cooperate so I connected the an OEM PB sensor and it worked. Hadn't noticed before, but the OEM PB sensors are ND 079800 sensors. This should allow me to connect this OEM sensor and configure it as a 079800 Baro sensor.

Just for info. 079800 is the Denso generic code for a MAP sensor, Denso numbers are typically Part type-part number.
You should retain the resistor and capacitor, that is your anti-aliasing filter.

[JHolland]

The OEM Service Supplement Manual further corroborates the fuelling profiles. Normal engine operation uses an Ne-Pb map for engine fuelling and ignition. Ne for Alpha-n, and Pb for SD. When a PB sensor is faulty/fails, the CFI ECU fuelling/ignition defaults to the Ne-Oth map.

The manual states that it only uses alpha-N if a MAP sensor is faulty (actually when both MAP sensors are faulty), so it usually runs SD, I would concentrate on optimizing that first.