14 Silverado L83 Single Turbo timing pull after shift

[Blown383]

Greetings everyone. I've got a 2014 1500 Silverado with a custom turbo kit. TSP Stage 3 cam, upgraded injectors and HPFP. Currently on about 15psi and the truck runs great. I'm currently working through the trans side of the tune. Everything is great. Single gear pulls are perfect. VVE and MAF are dialed pretty well, VT is dialed good. No throttle closures or timing pulls during single gear pulls. Looking for some help for a timing pull after shift. For about half a second after ashift, TM will come in and pull some timing, predicted and immediate axle source will switch to Trans and Trans S, final throttle torque request will drop to the 300s and it feels like a bog. I've attached a log and a screenshot.

I have maxed all the torque rate limits but I feel like I'm missing something on the trans side if the torque source is switching to Trans.

Screenshot 2023-03-14 124345.png
23-03-14 12-17-22.hpl

[GHuggins]

It's doing it every shift and since the shifts are respectfully .250 seconds and .150 seconds either you still have tm enabled too much or you have you desired shift times too low causing it to cut. Without a tune it's hard to tell what's been done...

[Blown383]

It's doing it every shift and since the shifts are respectfully .250 seconds and .150 seconds either you still have tm enabled too much or you have you desired shift times too low causing it to cut. Without a tune it's hard to tell what's been done...

Commanding to low of a desired shift time will cause a timing pull after a completed shift? Interesting. I'll have to load it back onto the dyno and give it a test. I can PM you the tune.

[GHuggins]

OK. Yes if it's not completing the shift as it's commanded then it can cause torque management to kick in and pull timing or throttle depending on how you have it set up. On 6speeds in particular I won't usually mess with shift times, but instead address it elsewhere.

[Blown383]

I sent the file to the email in your sig. Thanks!

[GHuggins]

I never got it. I did verify the old address worked, but also updated it to make it 100% exact if you want to resend it.

[GHuggins]

Got it that time.

[MORLOK]

I am guessing this only happens on part throttle and not WOT?

I had this exact problem on my truck. The only way I could fix it was to run a boost controller that can control based on pedal position and RPM. I run the MS PRO, but I think any Mega Squirt product can do it. Then set it to keep boost under 3lbs until 100% throttle.

To make a long story short. The torque control uses predicted airflow across the throttle blade at various positions and it can't account for boost (always assumes barometric pressure on the throttle inlet side). For some reason, when there is too much airflow at part throttle it will complete the shift, but still do that stupid after shift timing pull.