pressure vs tps for power commander v

Thanks for typing all that out for me claviger

Couple of other practicalities when home-tuning, if you intend to import trims from PCV into the ECU map, then at the start, set up the PCV map to have the same quantity of columns as the TuneECU map, and use the same pressure/%TP at the head of the column.
It will stand to you when importing.
The RPM rows may not entirely line up between PCV and TuneECU but that's just something you have to live with and adapt/interpolate for.

If using PCV autotune, it works reasonably well imo for pulling towards target AFR, if you can hold an RPM/%TP or RPM/MAP for a couple seconds, but you have to get the map to ballpark manually to start with.
And finalise it manually.

Beware sometimes the autotune will get into a loop and make the AFR worse. When you see this happening then best zero the AFR in that cell/area and tune it manually.

If you're just adding a different exhaust or modifying the intake or something minor enough vs an established setup that has a map, autotune works well as the map was not far off anyway.
But if you completely modify the engine and fueling system, then you are basically creating a map from scratch... which is great sport.

R-III-R Turbo said:

Couple of other practicalities when home-tuning, if you intend to import trims from PCV into the ECU map, then at the start, set up the PCV map to have the same quantity of columns as the TuneECU map, and use the same pressure/%TP at the head of the column.

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A very important point I completely overlooked, thanks for adding that.

Claviger said:

A very important point I completely overlooked, thanks for adding that.

Click to expand...

Thank you for your very detailed answers. To both of you. I ordered the Power Commander and will plug it in once it arrives.

I rode the bike yesterday and I found something that looked strange to me. How the setup looks like is that I have a lambda probe mounted to a selfmade prolonged muffler. The tube from the lambda probe to ambient air is about 40cm long and 2cm in diameter. I measure the AFR every 50ms.

So here comes the strange thing. When in idle I see the AFR to be 15.5 with spikes towards 20. I would expect to see a lean AFR in low revs because of ITB caused by the large cam. However, when looking at my ECU short-term idle trims I see negative values of about -30%, meaning that the engine believes that it runs too rich and adds air. This honestly confuses me.

While riding until 3000 rpm I see an AFR of about 15 and on higher revs I see an AFR of 14.5 spot on. So my thinking is that I'm running very lean in low revs - which I would like to resolve of course. However, the engine thinks differently. I will go for a ride and check the short/long-term trims as well as the narrow band lambda voltages while idle and when riding. I'm open to ideas here.

It might be that I get tricked by the 40cm pipe that sucks air back in. I will prolong that by a 100cm tube just to see how my AFR readings change on my wideband lambda.

Overall, these short/long-term trims can be trusted right? It targets whatever is set in the AFR table, for me this is 14.5. With a large cam I would only see an issue if the idle trims would want to add fuel because of the ITB, right?

I just read the trims from my bike. These readings tell that it heavily tries to lower fuel meaning that it is running too rich. My feeling is that I can trust these numbers, what do you think about the fuel trims in general?

Are you not deleting the factory narrow band O2 and unticking it in TuneECU map?

Leaving them on will just fight what you're trying to do

R-III-R Turbo said:

Are you not deleting the factory narrow band O2 and unticking it in TuneECU map?

Leaving them on will just fight what you're trying to do

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I don't have the Powercommander yet, I just ordered it - I will plug it in as soon as it arrives. This is why for now it is on to see what is going on as this information will help me later on to understand if the Powercommander is going in the right direction.

The ECU trims suggest that idle should be slightly leaner and the off-idle region should be a lot leaner. This is what the Powercommander should do as well.