Im working on my 2007 Dyna Low rider using a PV3. I noticed i have the PIDs VE and NEW VE in the log.
First question: Dos anyone here find these channels useful for tuning the VE?
Second: How is the New VE calculated? id assume it uses the closed loop feedback/fueling errors to calculate the New VE value. Much like logging the STFT errors in a histogram then applying them to the map
Third: Is the New VE actively making changes to the fueling while the bike is running??

Below are some screen shots and explanations with some custom math in MegaLogViewer.

First the STFT value im getting in the screen shots is taking the channel " Front or Rear closed loop intergrader" and adding (-100). This gives the "STFT" value. 95 + (-100)= - 5% fuel trim.

The math for calculating the error or difference between the "VE front" and "VE New Front" or rear goes like this. ([VE Front]-[VE New Front])/(([VE Front]+[VE New Front])/2)*(-100)
If the VE Front is 100 and the VE New Front is 95 : (100-95)/((100+95)/2)*(-100) = - 5%

Below in the screen shot you see the NEW VE (Red line) and it is higher then the VE (white line). The STFT is positive and so is the VE ERROR.
Notice that the STFT and the VE ERROR are not exactly the same.





Below is an example where the NEW VE is lower then VE and the VE ERROR as well as the STFT are both in the negatives as a result.



Any insight to the NEW VE channel is appreciated. is it actually making changes to fueling or any thing els while running? or is it just a calculated out put?

 

This is a good queston. I'm trying to learn this stuff too, to apply to my PV.

 

basically the formula is Aff*cli* ve = new ve.

i find it useful for sure.
-Steve

 

Im used to GM so if i understand right adaptive fuel factor is like LTFT and closed loop integrator is like STFT.

So if we change the AFF and CLI over to a 1.XXX or 0.XXX (to make it a percentage to multiply by. Sorry im not a math person lol)
AFF of 101.56 = 1.0165
CLI of 105.46 = 1.0546
VE = 101
1.0156 x 1.0546 x 101 = 108.279 is the new VE.

Thats good to know. Ill use the new VE channel to make my next set of changes to the VE tables and see how it goes thanks for the input!

 

yep. Aff is LTFT and CLI is STFT.

Sounds like you’re on the right track. Get your fuel right, then you can move on to timing. Good luck!
-Steve

 

Just make sure that you understand your missing most of the real data, so what you see on the screen may well not be the truth. This is best done doing steady state and slow changes in engine speed to allow the data that you do get, to settle down. Trying to use things that are changing fairly quickly can and does lead you down the rabbit hole looking for the wrong answer.

 

yes. Sorry Steve, I should have mentioned that. On my bike, I get about 20 frames /sec, so I loose about 40 frames at 3000 rpm!

 

i have filtering set up on my histogram for PE decel acel open loop all that good stuff. i just wanted to under stand the math behind it befor i used it as a reference. Im still using auto tune basic while riding and then a data log after auto tune to reference when im hand smoothing the VE.

 

The OP has a 4 pin DTC port so he is going to be lucky to see 2 fps, so at idle he is missing ~75% of the real data and it only gets worse as the engine speed increases.

 

If it was missing 75% of the data at idle and gets worse with engine speed then it would be completely useless...