Ability to offset a logged sensor or PID by time or frames

[GNXClone]

I'm sure this will never happen, but here it goes...

When logging using the WBO2, I've noticed there is about a 300 msec delay between the time the AFR actually changes, and the time the WB sends the reading back to the HPT interface. I know this is called transport delay in ECM terms.

The problem is, this misalignment of the WBO2 data with the rest of the log (commanded AFR, RPM, MAP) introduces a fair amount of error in the histograms.

If we could offset the logged sensor or PID either by a number of frames or time, this would help reduce that error tremendously. As it is, in order to be accurate, I have to find where the AFR needs correcting, then move the cursor back about 300 msec. Then I can use the data I see here to find the true AFR error%, RPM and MAP. This is quite tedious to say the least.

Thank you, and have a nice day.

[SSUte01]

I know it's perhaps not the most elegant solution, but you could always export the data as a .csv for example and then manually offset the AFR against all the other columns by a chosen number of frames. This means you obviously don't have the convenience of histogram format for VE tables and the likes however it may reduce the tedium somewhat depending on what you are doing

[DSteck]

Once your exhaust flow gets up to a decent rate, there isn't much delay.

[GNXClone]

Once your exhaust flow gets up to a decent rate, there isn't much delay.

My WB is probably too far back in the stream. The approximate 300 msecs delay I see is at WOT.

Just something I'll have to deal with.

[DSteck]

On tip in, or actually during sustained WOT?

[GNXClone]

On tip in, or actually during sustained WOT?

That's a very good point that I hadn't considered. I get the offset by comparing the time stamp of the change in commanded AFR versus the timestamp of the actual change in AFR as detected by the WB. These happen at tip-in and when the throttle is lifted.

[DSteck]

I try to start a WOT pull as low as possible. You can get it dead nuts, and then later tip in from a higher rpm and see that same delay. I wouldn't stress over it. The duration of that delay will vary with exhaust gas velocity anyway.

[LSxpwrdZ]

This is why I slow the rising rate of the dyno down in sections to do WOT tuning so that the RPM's don't climb so fast to create mis-plotted values. It's hard on the motor which is why I do it in sections instead of one full sweep that takes 20 seconds lol