Reading rpm is not constant!

[sarbetto]

Hello,
Sorry for my English.
I have a motec m800 unit mounted on a motor Aprilia SXV 550.
I managed to do a sketch of the map, but my problem is that the unit does not perform a reading at constant speed, in the sense that while it is running (example 7000 rpm) gives me values ​​ranging roughly from 6500 to 7500, this does not allow me to perform a correct mapping of both stoichiometries and both the advances. The dealer gives me the constant values ​​so I guess it's a matter of settings. I tried to change the filters but the ref does not get any improvement. Taking a capture signals ref does not have noise.
I hope someone can help me.
Thank you very much.

[stevieturbo]

Does the ref/sync capture show a good clean stable signal though ?

And is the capture definitely form when the problem is occurring ?

Can you upload it here ?

[Holmz]

As the number of cylinders goes down and the flywheel inertia decreases the RPM gets further and further from constant. Even big diesel gensets with massive flywheels have measurable variation.

I would assume that a 2 cyl engine would have variations during a cycle that looked like many RPM, but I am not sure if we are talking about the same things.

If one looks at the reference there will be some "accordion playing" where the waves are compressed during the compression phase, and the expanded or "un-squeezed" after the plug fires.
Depending on how one looks at it, and over what time frame, determines what variation they see. But the engine is far from having a smooth speed.

[sarbetto]

Hello thanks to all of the response,
then the speed is almost constant (+ - 100 rpm) as I see from the dyno values ​​very consistent, ranging from very little. Then the difference should at least feel it by ear as you do not talk about revolutions but of thousand rpm. The fact that they are not perfectly constant is true but have a range of 1000 rpm, seems excessive to me. The only thing that makes me slightly better is the "trigger voltage ref" then nothing for the rest .. I attach the capture.
We hope to find a solution together.

[stevieturbo]

Upload the map as well.

Crank and cam trigger traces on the scope look to be very good and clear, no noise, no interference

[sarbetto]

what precisely the map?

[Holmz]

What does one open the .rcs2 file with?

[stevieturbo]

What does one open the .rcs2 file with?

Open it from the ref/sync capture within the Motec software. Select the sync capture and open it

@ sarbetto

The Motec map file, calibration, tune, whatever you want to call it. So all crank/cam trigger settings can be viewed

[sarbetto]

These are the screenshots of the settings

[Holmz]

What does one open the .rcs2 file with?

Open it from the ref/sync capture within the Motec software. Select the sync capture and open it

@ sarbetto

The Motec map file, calibration, tune, whatever you want to call it. So all crank/cam trigger settings can be viewed

Thanks... got it. But no way to export that out... Like to a .csv file to look at it with something else (e.g. MATLAB)