2003 Silverado SS slow 1-2 shift at WOT

[Reckless95z]

I am having trouble figuring out why this level 7 finishline 4l65E is taking so long to complete a 1-2 shift at WOT. Huron speed turbo kit tuning in 3 bar OS, yank 3k stall converter.
Thanks
2003 Chevy Silverado SS TURBO.hptss 10-30-21 4.hpl

[blindsquirrel]

Don't zero out the Shift Timing tables, give them some sort of real number. .250 is a good default.

[Reckless95z]

Don't zero out the Shift Timing tables, give them some sort of real number. .250 is a good default.

Okay will definitely try that. I was under the impression that once it is modified mechanically it wouldn't matter but i will put it back report back to you. thanks

[5FDP]

Not sure I'd completely turn off the transmission torque mngt either, leave a little in there.

The part throttles normal tables 100% throttle position MPH does not match the full throttle shift speed normal mph either.

Just curious as well. What injectors are those? Seems a bit odd that your VE has such low numbers for injectors that are 70lb/hr?

Also remove the 1 bar MAP channel and add knock retard to your logs.

[Reckless95z]

Not sure I'd completely turn off the transmission torque mngt either, leave a little in there.

The part throttles normal tables 100% throttle position MPH does not match the full throttle shift speed normal mph either.

Just curious as well. What injectors are those? Seems a bit odd that your VE has such low numbers for injectors that are 70lb/hr?

Also remove the 1 bar MAP channel and add knock retard to your logs.

I was playing with WOT shift MPH and forgot to change the part throttle thanks you. As for injectors they are FIC 1200H, i was hitting the cylinder airmass wall when we had more boost in it so I halfed the VE, IFR and adjusted the timing tables to move the cylinder airmass down to not get the airflow code p1514.

How much Torque mngt should i put back in it?

I have KR in the charts but i will add to the list

[Reckless95z]

I added shift time back in, made no difference. I also added some torque management back in about 20% of what the stock was, and that made the shift even slower. I lowered the boost down to 10psi thinking it was maybe blowing through the converter. That also made no difference. It seems to be slow shifting all the time during the 1-2. I am starting to think it is not tune related and maybe a mechanical problem.

[1badc10]

I added shift time back in, made no difference. I also added some torque management back in about 20% of what the stock was, and that made the shift even slower. I lowered the boost down to 10psi thinking it was maybe blowing through the converter. That also made no difference. It seems to be slow shifting all the time during the 1-2. I am starting to think it is not tune related and maybe a mechanical problem.

Any reason why your "WOT Shift Speed vs Shift - Normal" is set the way it is? Your Upshift speeds are the same values as your Downshift speeds. Set the downshift speeds lower than the upshift speeds. This is what your latest tune file has:

1->2 Shift: 36
2->3 Shift: 66
3->4 Shift: 256
2->1 Shift: 36
3->2 Shift: 66
4->3 Shift: 256

I'd change that to something like this (maybe match your Part Throttle Table's 100% Throttle values):

1->2 Shift: 36
2->3 Shift: 66
3->4 Shift: 256
2->1 Shift: 31
3->2 Shift: 61
4->3 Shift: 90

As for shift timing, I've been adjusting the 1->2 on my '15 Yukon (L86/8L90) the past week. Factory configuration was disappointing. Have data logged, adjusted, logged, adjusted a few times. I've been fortunate to have great luck reducing that shift time from 1.6s (longest) down to 0.5s (as of this evening). Reducing the shift time for the desired transitions (1->2 and 2->3) in 5% reduction helped to go from 1.6s 1->2 to 0.9s. Another 5% reduction proved to be too much, so I reverted to the previous 5%, then reduced the entire table by 2%. That brought the WOT 1->2 down to 0.5s (quicker shift feel, in part throttle and WOT scenarios). I've logged three (3) WOT runs, receiving repeat results. Will leave things alone, as I'm satisfied with the results (for now). I'm NOT adjusting pressures anywhere, as this Gen has adaptive learning that adjusts pressures to "help" meet the desired, specified shift time. Can't say this'll cure your issue, but that's what'd I'd go after. We have different transmissions (obviously), but I don't have any shift time faster than 0.273s (highest torque vs RPM row of cells).

That said... In my 24x converted 4L6xE equipped '95 Impala SS (383ci LT1 - 507hp/446lbft), my shift table is as follows:
1->2 Shift Time: 0.325 (across the entire row)
2->3 Shift Time: 0.300 (across the entire row)
3->4 Shift Time: 0.275 (across the entire row)

Before I sold the car, it was street driven (daily) in a spirited fashion (loved to catch a red light, just to beat on it). LOL Shifts were nice & firm, with absolutely no noticeable delay. Max pressure setting was 96psi.

Good luck! ;-)

[Reckless95z]

Any reason why your "WOT Shift Speed vs Shift - Normal" is set the way it is? Your Upshift speeds are the same values as your Downshift speeds. Set the downshift speeds lower than the upshift speeds. This is what your latest tune file has:

1->2 Shift: 36
2->3 Shift: 66
3->4 Shift: 256
2->1 Shift: 36
3->2 Shift: 66
4->3 Shift: 256

I'd change that to something like this (maybe match your Part Throttle Table's 100% Throttle values):

1->2 Shift: 36
2->3 Shift: 66
3->4 Shift: 256
2->1 Shift: 31
3->2 Shift: 61
4->3 Shift: 90

As for shift timing, I've been adjusting the 1->2 on my '15 Yukon (L86/8L90) the past week. Factory configuration was disappointing. Have data logged, adjusted, logged, adjusted a few times. I've been fortunate to have great luck reducing that shift time from 1.6s (longest) down to 0.5s (as of this evening). Reducing the shift time for the desired transitions (1->2 and 2->3) in 5% reduction helped to go from 1.6s 1->2 to 0.9s. Another 5% reduction proved to be too much, so I reverted to the previous 5%, then reduced the entire table by 2%. That brought the WOT 1->2 down to 0.5s (quicker shift feel, in part throttle and WOT scenarios). I've logged three (3) WOT runs, receiving repeat results. Will leave things alone, as I'm satisfied with the results (for now). I'm NOT adjusting pressures anywhere, as this Gen has adaptive learning that adjusts pressures to "help" meet the desired, specified shift time. Can't say this'll cure your issue, but that's what'd I'd go after. We have different transmissions (obviously), but I don't have any shift time faster than 0.273s (highest torque vs RPM row of cells).

That said... In my 24x converted 4L6xE equipped '95 Impala SS (383ci LT1 - 507hp/446lbft), my shift table is as follows:
1->2 Shift Time: 0.325 (across the entire row)
2->3 Shift Time: 0.300 (across the entire row)
3->4 Shift Time: 0.275 (across the entire row)

Before I sold the car, it was street driven (daily) in a spirited fashion (loved to catch a red light, just to beat on it). LOL Shifts were nice & firm, with absolutely no noticeable delay. Max pressure setting was 96psi.

Good luck! ;-)

I changed everything like you stated and still no luck. I did notice that the throttle is getting cut down by like 5600RPM for some reason. I am going to move all of the ETC RPM limiters up and see if its hitting one of these. I am at work right now so I dont have a log to post, but i believe you will see this in the last log i posted.

[1badc10]

Okay will definitely try that. I was under the impression that once it is modified mechanically it wouldn't matter but i will put it back report back to you. thanks

Looking back it an earlier reply, what do you mean ?modified mechanically?? Did you have FLT install a vacuum modulator? If so, that will certainly bypass any commanded shifting, relying on vacuum pressure.

[IARLLC]

As a quick test of the mechanical soundness of your transmission you can lower your shift rpm and full throttle (and 100% row of part throttle) shift speed by a lot. This will at least show you if your trans is healthy. If it works out, you can raise your shift rpm more or less to the desired shift rpm and gradually ease your shift speed up until it is where you want it. Your trans might just need more lead time than it gets when things are set "accurately".

[Reckless95z]

As a quick test of the mechanical soundness of your transmission you can lower your shift rpm and full throttle (and 100% row of part throttle) shift speed by a lot. This will at least show you if your trans is healthy. If it works out, you can raise your shift rpm more or less to the desired shift rpm and gradually ease your shift speed up until it is where you want it. Your trans might just need more lead time than it gets when things are set "accurately".

Quick update, the problem ended up being that the tip in retard was pulling 9 degrees of timing during the whole pull and through the shift. I logged burst knock and knock retard, for some reason knock retard was not being logged. Ended up softening the TIP in knock by 30% and now i get no knock retard during a pull and it shifts fast and firm. Thanks everyone for the help. I appreciate it.

[IARLLC]

Thanks a lot for the update! That will help a lot of folks in the future.