[Rednaxs60]

Will get to the bottom of this.

[Rednaxs60]

Garage trial this morning using data from the service manuals of 10 degrees BTDC at idle up to 48 degrees max timing. The engine is timed at 10 degrees BTDC at idle and operates quite smooth - minor tweaking g will be required a the engine tune progresses. From this new information expect timing advance to start at approximately 1500 RPM. The new engine tune is using @PSIG recommended table load values from post #67283. These may be adjusted as the engine tune progresses.

[Rednaxs60]

Is the "Juice Box" still a go? Found this on-line and in the manual. It would be a possibility for a small ignition only project I am thinking of, specifically replacing the ignition control module (ICU) on the carbureted '85 to '87 GL1200 Gold Wings. Nothing lasts forever.

[JHolland]

Juicebox uses teensy 3.5 so, unless it gets updated, its as good as dead.

[Rednaxs60]

Thanks - continuing with Plan "A"

[Rednaxs60]

Weekend work - Bit cool for road trials. Baro sensor (old OEM PB sensor) installed, wiring to be done. Using the 5V sensor feed and ground, separate wire for signal to ECU. Using IDC pin 17 to the A15 in the photo area. Local electronic component shop out of 470 Ohm resistor so using 430 Ohm with a small capacitor to ground. Checked for continuity from the ECU connector through to A15 and all is good (my PCB soldering skill is still a bit rough). Read up on gpineau's process and will probably mirror what he did to test the sensor.

Thinking about the ignition timing. If the lambda/AFR is indicating a rich fuel condition (corroborated by the spark plugs) should the timing be advanced or retarded? Will find out but thought I'd ask.

[PSIG]

Thinking about the ignition timing. If the lambda/AFR is indicating a rich fuel condition (corroborated by the spark plugs) should the timing be advanced or retarded?

The fueling should be corrected to best value for the conditions. This has not been done. The ignition timing is adjusted to provide best timing for the conditions. We try to avoid making good adjustments on bad settings, as they will change when the bad settings are corrected.

Note here that idle timing, tip-in throttle, off-idle, initial acceleration, etc, are all different conditions. In older mechanical-advance terms, the idle timing was actually the best value for tip-in throttle, where cylinder filling increased dramatically while rpm has not yet increased significantly. Substantially retarded, appropriate for the first moment of throttling-up. Hmm. Think on that for a bit, as it is a different perspective to "idle" timing. It's not.

Flash forward to today, but we often have different timing at idle than before. Sometimes it is still low (retarded), but for completely different reasons, and commonly to use other schemes such as torque reserve for idle stability. The question is, what are you tuning for and why? Because somebody else did it that way, or because it is what the engine needs to run best? Hmm.

When everyone went to electronic timing with instant change to appropriate values at any point, we could now have true idle timing value, true tip-in timing change, and so on. The point here is to consider what you think this setting is really for, and what it should be to meet the conditions it is in right now. Alternatively, as part of a scheme to do something different and better - but you need to know what that scheme and goals are.

Yeah. Whoa. New thinking. Cool.

[Rednaxs60]

@PSIG - thanks for the reply. I asked the question because when I went to 10 degrees BTDC for the idle timing, I went up/down the VE table cell values and had to lean out the cell numbers, not much but noticeable. Not too concerned with the 1000 to 2000 RPM range, this is a transition area. Concentrate on the region above 2000 RPM then input a smoothing timing value in the 1500 RPM range. I know the fueling is "rich", so my options are to reduce the amount of fuel - VE table cell changes (maybe complementary change in timing - retard), or give the fuel charge more time to burn (advanced timing).

With this in mind, will be starting road trials again, and doing structured (yes, I can be) trials. Will pick a set of parameters (engine RPM, Gearing, Speed), adjust VE first, then timing for that specific set of parameters before moving on. Take note of the lambda/AFR readings and if reasonable, adjust AFR table. Pick a new set of parameters, adjust as required, repeat as necessary. Understand that once this is done a need to revisit the tune from the start will be required, things change.

Will be keeping RF, spark duration, coil dwell and other settings on the sidelines for consideration as I progress. "When you have eliminated the impossible, whatever remains, however improbable, must be the truth" - Sir Arthur Conan Doyle stated by Sherlock Holmes (Spock said this as well).

Reading up on using a baro sensor, not using a baro sensor. Understand what Speedy does without one. It has been mentioned that for initial tuning set the Multiply VE Value by MAP ratio (think this ratio is MAP divided by Baro signal) to fixed so that the tuning is static for one set reading. Makes sense, but when this is set to Baro, may have to revisit the tune. For now the baro sensor will be fitted but not used. Noticed that the settings for the Denso 079800 sensor are: 0V - "0" kPa and 5V - 173 kPa. Will plot this against the values I have for my 079800 sensor.

As you mention, if it was easy, everyone would do it.

[Rednaxs60]

Baro sensor installed and connected. Used the TS ND 079800 settings. Adjusted the high end to match the MAP sensor on start - have to do the lower end. Will leave "OFF" for now, but it works. Checked the FP circuit, Speedy is doing what it should, thinking this FP is on its way out, only some 39 years old. Plastics on today, then road trials.

Reading up on coils and coil saturation current. Premature at this time, but the information is telling in that not all coils, or other parts/components for that matter, are created equal.

Need to make a test harness (have amp shunts as was recommended a while ago), or get a AC/DC amp clamp for small wires to determine saturation current so that the coil dwell can be optimized for various voltage and operation levels. Not too worried about the voltage correction since the alternator output at 1000 RPM is the same as at 3000 RPM. Will do the temperature testing to adjust the coil dwell at this time - use a heat temp gun and the finger test. The COP dwell setting used presently is the setting from a GW GL1100 carb to EFI conversion and this fellow went with sequential COP units. He used a Microsquirt ECU.

[PSIG]

I see a gap in concept, and I hope you will give me an opportunity to offer a different mind-set of the concepts.

… I went up/down the VE table cell values and had to lean out the cell numbers, not much but noticeable.

Why did it need leaning-out? What was your goal? Why did you think it was rich of something? What something is that? Why is important to the concept.

… I know the fueling is "rich", so my options are to reduce the amount of fuel - VE table cell changes (maybe complementary change in timing - retard), or give the fuel charge more time to burn (advanced timing).

Yes, to a goal. I see a small but significant gap in concept. It says OR instead of AND. If you adjust one you adjust the other, each + and - to find optimal values with data, because fuel and spark work as a team. What optimal values? That depends on the goals at that point of operation. Adjust your mindset from rich or lean to optimized. "I know it's rich lean not optimal, and I need to find the fuel and timing values it is optimal."

Will pick a set of parameters (engine RPM, Gearing, Speed), adjust VE first, then timing for that specific set of parameters before moving on.

Yes! But adjust to what? Adjust to the goal for that point of operation. We can have many goals, but one goal is primary at a specific point.

For most general applications, the goal for initial tuning is peak efficiency for either torque (power) or economy. Pick which one fits there, and tune (using data) to achieve that goal, at that point. There are other goals and efficiencies, but we're not there yet, and set our base tune on those two as a baseline. Modify for other purposes after the tune foundation is built.

In the generic example table below, note areas 2 and 3 have max torque as the typical goal, and the other areas do not require max torque and so are targeted for minimum fuel consumption. Some efficiency is always maximized, and if it's not torque we need, then it's economy to gain. We tune with data to find max torque fueling and timing to support it, or max economy fueling and timing to support it, for every point on the tables.

You pick which goes where for your purposes, goals, preferences, etc. Print a copy of your table, and mark or highlight every cell for which goal each cell will have - torque or economy. Tune each area for that chosen goal. That's job one. Crawl before you walk, and walk before you run.

Cim526-L-1[1].jpg (143.26 KiB) Viewed 469 times

Take note of the lambda/AFR readings and if reasonable, adjust AFR table.

Reasonable for what? You see where we're going with this at every point. To repeat, we never tune or adjust to an AFR. Get "adjust AFR" out of your head. We only tune to the chosen peak efficiency, then read what AFR that peak efficiency produces. The result of our tuning to peak values. Enter that value into the AFR Table , in order to maintain that best value you found in the future. Repeat in a new area. Connect the dots.