Different methods for building a proper ignition table

[vspdave]

D.I.Y route that I have developed needs some help, a new 7.2mm de-stroked 639cc engine specification is taking awhile to tune.

I have built a fair amount of ignition tables for various road race motorcycle engine builds and always feel like I am wasting a huge time filling in those tables with good data. I would imagine serious teams (with resources to match) build their tables using combustion analysis rigs however all we have is a Dyno with normal engine data logged. The fact that you are operating with a heavy load on the engine means 2 or 3 pulls before you need to cool everything back down for 15 minutes before you can repeat the process, and so on etc

Would it be possible to setup the Motec M1 series to automatically add 2 degrees to the overall ignition table with a push of a button (or better yet automatically when you get back to "x" RPM) between pulls? or are there more advanced methods out there that tie into the torque output and cycle automatically?

[David Ferguson]

I have the torque output from my dyno passed via CAN bus into my M1 firmware package. I can now log and monitor that value in M1 tune. I have an ignition tuning page, where I hold the RPM/load steady on the dyno, and vary the ignition timing. It has a XY graph showing torque vs. ignition timing. I can then pause the data, and scroll back to find the peak torque and put that value (or one slightly less that makes almost as much torque) in the ignition table cell.

One of these days, I will add a Quick Adjust function that will sweep the timing and determine that automatically.

[vspdave]

Well you guys always have good information! I just need to get a system together that is quick to avoid wasted time changing values.

Was hoping Motec had something available, or maybe someone will build an option for the M1 series Ecu's and market it.

[Stephen Dean]

Hi,

I have always used the Ignition Timing Trim Overall parameter to quickly add or remove timing when tuning an engine, and then making it a permanent change by using the multiplier/divider functions in the Main Ignition Table.

The difficult part of writing a learning table to do this is that it needs to have feedback of some sort that it uses to compare the different timing maps against. This is easy with the fueling as this compares the Lambda value against the Lambda Aim. Unless there is some feedback from the dyno providing the engine torque into the M1, there really isn't any easy way of doing this, other than running it to the knock limit and then taking timing out but this cannot guarantee that it is optimised timing.

[vspdave]

I did look into knock sensor tuning for MC based engines about 6 years ago and was talked out of it, sounds like the initial setup can be tricky on motorbike engines.

Appears that it would be possible to put something together on the M1 series to vary ignition timing and compare to torque output, probably using a step test. Now to figure it out...

Thanks for all the information.

[Suprafied]

I have the torque output from my dyno passed via CAN bus into my M1 firmware package. I can now log and monitor that value in M1 tune. I have an ignition tuning page, where I hold the RPM/load steady on the dyno, and vary the ignition timing. It has a XY graph showing torque vs. ignition timing. I can then pause the data, and scroll back to find the peak torque and put that value (or one slightly less that makes almost as much torque) in the ignition table cell.

One of these days, I will add a Quick Adjust function that will sweep the timing and determine that automatically.

What brand of dyno? Dyno dynamics? mainline?

I'm looking to do this on my friend's dyno during my next session if optional.

DP

[David Ferguson]

My dyno is a Dynapack, and I added code to my custom firmware to receive the dyno values, and create channels like "Dyno Measured Torque". This can then be logged or used in M1 Tune.

[TurboTito]

I know this post is old...but would holding the engine RPM and Load in a steady state, then tuning the timing to where the best vacuum is achieved work? Then do this until you have populated all cells the best that you can, using a dyno with a brake would help.