7.3L 6R140 not shifting as schedule

[Ford385]

I'm not able to get the trans to shift at the scheduled shift OSS.

for example: I have the 2-3 shift set at 2329 (OSS) and it seems it commanded the shift at 2163. I'm having the same issue for each of the upshifts.

Any help would be appreciated. I've added the tune and log files below.

7.3L_6R140 (F250 Engine & E350 Trans)(baseline+7).hpt
7.3 6r140 baseline+7 - 45.hpl

[TransGo Robert]

I have no idea why you would want to use the OSS to decide when it shifts instead of ISS or engine RPM, but what is happening here is that it takes 0.5 seconds for the shift to start once commanded, so the computer is commanding it at 2163 trying to make it happen at the desire 2329. it does not miss by much, the shift start at about 2335. If you need to use the OSS to decide when it shifts, you will need to factor in that half a second before the computer command and the actual start of the shift.

[Ford385]

I have no idea why you would want to use the OSS to decide when it shifts instead of ISS or engine RPM, but what is happening here is that it takes 0.5 seconds for the shift to start once commanded, so the computer is commanding it at 2163 trying to make it happen at the desire 2329. it does not miss by much, the shift start at about 2335. If you need to use the OSS to decide when it shifts, you will need to factor in that half a second before the computer command and the actual start of the shift.

Thanks Robert. I listed the OSS as that's how the shift schedule is entered in the tune file. I use a spreadsheet that translates OSS to engine RPM and MPH; I do all my "tuning" in the spreadsheet using engine RPM and MPH, then copy/paste the translated OSS to the tune file. In the listed example, the 2329 OSS is 5,400 engine rpm or 59 mph.

I was under the impression that the shift schedule was when the shift started and the additional time (0.5 seconds) was in addition to the shift - i.e. shit starts at 5,400 and completes around 5,800 rpm. I guess it's the other way and I need to set my shift point to 5,800 if I want to actually shift at 5,400?

[TransGo Robert]

Thanks Robert. I listed the OSS as that's how the shift schedule is entered in the tune file. I use a spreadsheet translates OSS to engine RPM and MPH; I do all all my "tuning" in the spreadsheet using engine RPM and MPH, then copy/paste the translated OSS to the tune file.

In the listed example, the 2329 OSS is 5,400 engine rpm or 59 mph.

I was under the impression that the shift schedule was when the shift started and the additional time (0.5 seconds) was in addition to the shift - i.e. shit starts at 5,400 and completes around 5,800 rpm. I guess it's the other way and I need to set my shift point to 5,800 if I want to actually shift at 5,400?

Like you, I also would have thought it would be when the shift is commanded, but looking at your log you can see that the command always happens roughly 0.5 a second before the ISS starts to drop and that drop correspond to what you are aiming for (2329 or so). That's why I came to the conclusion the computer is actually taking the lag into consideration. I am much more knowledgeable about transmissions then tuning, I am amazed that they would use the OSS to decide when it shifts instead of engine RPM but hey, they must have a reason to do it that way.

[TransGo Robert]

Thanks Robert. I listed the OSS as that's how the shift schedule is entered in the tune file. I use a spreadsheet that translates OSS to engine RPM and MPH; I do all my "tuning" in the spreadsheet using engine RPM and MPH, then copy/paste the translated OSS to the tune file. In the listed example, the 2329 OSS is 5,400 engine rpm or 59 mph.

I was under the impression that the shift schedule was when the shift started and the additional time (0.5 seconds) was in addition to the shift - i.e. shit starts at 5,400 and completes around 5,800 rpm. I guess it's the other way and I need to set my shift point to 5,800 if I want to actually shift at 5,400?

Here's a screenshot that might help to illustrate what I am talking about. The yellow vertical line I put is when the shift is commanded, the orange one is when the actual shift starts happening, and finally the red one is when the shift is finally done. 0.508 second between the yellow and orange cursor and a total of 1.783 second between the yellow and red cursor (command vs completed shift) 2-3.png

[Ford385]

Thanks Robert. This is very helpful.