Bad RPM curve in datalog

[Artem-makarchuk]

I have a problem with bad RPM curve in S300 datalogs. It isn't smooth and erratic.
I have a problem when loading datalog to Virtual Dyno.

Engine work fine, good ground, good distributor, new cap, wires, plugs, plug gap. I don't think that is misfires.


It's B20 VTEC Turbo 0.75 bar.



It's D16 Turbo 1.9 bar.

I saw some another logs of different cars, ecu , engine (NA / Turbo) and they all have this problem.

This bad RPM reading it's feature of distributor type ignition ???

How I can get
smooth RPM line in datalog ??

[Spunkster]

Have you discussed this issue with your tuner? Is the tach in the vehicle jumping in the same way?

[Artem-makarchuk]

Have you discussed this issue with your tuner? Is the tach in the vehicle jumping in the same way?

I'm tuner and I have this trouble with new version of Virtual Dyno. In Flash Pro log's no problem, rpm curve smooth.

This erratic line of RPM you can see only in big zoom in Smanager. Tacho is ok and working fine.
I think it's a problem with old ignition system style. I'll try to make CR filter for this pin on ecu to get smooth RPM curve.

I want to see another log's of TURBO honda's with dizzy at full throttle.