MAF Scaling - Open/Closed Loop Fueling info

[solidONE]

I added a little more + compensation in the higher (50~165 g/s) air flow cells above 68F and the OL error is even worse in the initial log than previous logs. CL is now all over the place in 95F temps....

[Toyota John]

Has anyone tried turning off Closed loop fueling by filling in the whole table with 12.5 and then using the open loop part of the program to scale? I would think it would be easier by eliminating the trims from affecting it. I wouldn't you get the same results?

[Kodename47]

For those who want to try aligning the PI and DI systems, I've found that the max opening time for the stock port injectors is ~30ms. Any further than this and you're pushing it on pure PI. The DIs are able to sustain higher RPM on their own but as I'm boosted I'm not willing to test the boundaries. My advice is that if you know you're on the boundary of PI use, then I'd go to the same RPM in DI and that way you've got good comparison data without risking anything.


I've been trialling a way to fine tune the DI Fuel Pressure Compensation tables to enable the PI and DI to be closely matched.


My method has been a bit all over the place but what I reckon is a good idea:
- Scale MAF in PI only with combined CL and OL if possible.
- Do CL scaling with new MAF scale for DI only to compare and see if an injector scaling change is required.
- Once the difference is minimal, fine tune the DI Fuel Pressure Compensations


Obviously there are things to consider, like max possible injection time and the OL portion of the MAF scale so that you don't run excessively lean.


Any questions/ideas welcome.

[Toyota John]

I tried to load my loaded data for Closed loop and it does nothing? No date is imported and not box pops up for the closed loop. I tried to load open loop to with a WOT pull i did last night and a bx pops up saying No WOT date. What I am doing wrong?

[solidONE]

Originally Posted by Toyota John

I tried to load my loaded data for Closed loop and it does nothing? No date is imported and not box pops up for the closed loop. I tried to load open loop to with a WOT pull i did last night and a bx pops up saying No WOT date. What I am doing wrong?

What are you using to take data logs? If OFT, you need to delete the first three lines in the log file.

[solidONE]

So I've come up with a compromise with the MAF temp compensation. Since I was able to make one for 68F and another for 100F, Ive decided to combine the two. I was able to modify the temp compensation table to work in CL using my 68F MAF scale up to 120F IAT with satisfactory results, but not in OL. In OL it would consistently run leaner in higher IAT while using the 68F MAF scale regardless of what I did to the compensation table. I have now applied the 100F MAF scales values from 2.8 and up to my Temp comp modded 68F scale, so that it does not lean out in higher temps. The down side is that it will run slightly rich in cooler temps. I can deal with that. Will post logs of my results later.

[Toyota John]

Originally Posted by solidONE

What are you using to take data logs? If OFT, you need to delete the first three lines in the log file.

I am logging with ECUTEK

[Kodename47]

Originally Posted by Toyota John

I am logging with ECUTEK

Have you got the latest version of the scaling tool?

What parameters have you put in for the various settings?

[Toyota John]

I think I figured it out the closed loop. The min load limit was too high. Open loop is still a problem. It says "Sorry no WOT pulls were found in the log file". I logged the same things as the closed loop but I did one WOT pull per log. I made three logs and they all says the same thing.

[Kodename47]

@Toyota John as I requested, what values are you putting into the individual parameter settings? My guess is that you've not changed the throttle % to work with ECUtek, I set mine to 80%. Are you logging the commanded AFR or have you put your fuel table into the tool?

What was the minimum load limit for CL? The default was 0.05 which is fine.

[Toyota John]

Yup that was it. I had it set to 85%. I have Min load limit it .005 now. What AFR min and max should I have. Where can I find the rest of the setting for ECUTEK. I also cant get POL fueling to work. My open loop fuel table won't validate. Any ideas?

open loop
MAF Volts Min 0
WOT Stationary Point % 80
AFR Error 200

Closed loop
CL/OL 2
MAF volts max 5
IAT max 300
AFR max 15.5
AFR min 14
dv/dt max .5 (what it this?)

[s2d4]

Change in voltage over change in time.

Sent from my Galaxy Nexus using Tapatalk

[Kodename47]

Originally Posted by Toyota John

Yup that was it. I had it set to 85%. I have Min load limit it .005 now. What AFR min and max should I have. Where can I find the rest of the setting for ECUTEK. I also cant get POL fueling to work. My open loop fuel table won't validate. Any ideas?

open loop
MAF Volts Min 0
WOT Stationary Point % 80
AFR Error 200

Closed loop
CL/OL 2
MAF volts max 5
IAT max 300
AFR max 15.5
AFR min 14
dv/dt max .5 (what it this?)

Delete the .jar file in the directory and re-sync to get the latest run file.

My settings are:
open loop
MAF Volts Min 3
WOT Stationary Point % 80
AFR Error 10 - Unless you have changed your intake.

Closed loop
CL/OL 2
MAF volts max 3
IAT max 25C for NA - although I look for a max of 10C range max to min
AFR max 16
AFR min 13
dv/dt max 0.7-0.75 - I will run this twice on 0.7 and 0.75 to see if much changes.

dV/dt is the change in voltage over time, its calculated from your log. This will remove trims that occur due to quick changes in throttle. The lower the number, the smaller the rate of change so the better the results, but set too low and it will lose data. I think 0.7ish is a good setting. If you check the mean/mode chart and there is a wide scatter of results then reduce the dV/dt value.

Remember you can run the log with some parameters set to see what the data looks like and then re-run with reduced parameters to get better data. It's finding the right line that makes the results reliable not useless.

[solidONE]

Here is what I did with my compensation tables applied to a MAF scale that I dialed in for 68F IAT's with decent results in closed loop operation.



Modified Values:


Percentage difference:


IAT's of log:


Errors in 115~130 IAT's using a 68F maf scale with modded temp comp:



I've tried changing the individual values in the cells, but could not get desired results particularly in the higher voltage areas under OL operation. I'd also recommend experimenting with values changes between 8%~14% for the desired effect. I settled on 12% change in the higher temps.

Also, you should error on the high side for g/s values for voltages seen in OL operation (2.8v and up) when rescaling your MAF to prevent running overly lean in high temperatures. I think this is why the OTS OFT tunes AFRs seems to read so much richer than the target AFR in logs hitting 11.8:1 at times when the target is set closer to 12.5:1. It will richen up in cooler temps vs hotter temps due to how the MAF sensor reacts to different IATs (my theory).