RPM spike during shift?

[Mingus]

I have a Gen3 DBW 6.0, 101lb injectors, (NA) with a 4L70 with Corvette servos,
I had an earlier issue about the rpms limiting to 3500 when WOT. That issue was fixed when I recalibrated my MAF.
The issue now, is a spike in the RPMs during the shifts at WOT. I've read a few threads about rpm spikes and tried a few suggestions like reducing the shift timing. Although my shifts have firmed up, it will still spike during the shift.
I would like for the low power shifts to be softer, while firming up at High loads. Attached is the current tune and a log from yesterday with a WOT blip.
Could someone take a look and tell me what to adjust?24-2-19.hptWOT rev inbetween shifts.hpl

[SiriusC1024]

https://forum.hptuners.com/showthrea...l=1#post763183

I already tried to tell you. You've disabled torque truncation.

Engine>Torque Management>General>Spark Retard and >Torque Loss % need to be returned to stock. Those are torque maps.

Trans>Torque Management>Torque Reduction is the torque request that references those tables. If you want to reduce shift torque truncation this is where you do it.

Don't zero out any of them. Put them back to stock. Reduce the trans torque a little at a time if you want.

Look at Engine>Torque Management>General>vs RPM. That's a torque limiter for the torque converter. Do you have a stronger converter? Put it back to stock. So you have no torque limit for the torque converter, shift lock enabled (TCC stays locked during a shift), and shift torque truncation non-existent. That's how things break.

[Mingus]

[URL]

Look at Engine>Torque Management>General>vs RPM. That's a torque limiter for the torque converter. Do you have a stronger converter? Put it back to stock. So you have no torque limit for the torque converter, shift lock enabled (TCC stays locked during a shift), and shift torque truncation non-existent. That's how things break.

Ahh, I'm starting to get it now. I wish there was a list of all of these functions that goes into depth of how they work and why they are there. I see the "explanations" at the bottom of Editor, but they are pretty vague sometimes.

I've got all of those areas set back to stock, and might get in a test drive this afternoon.

Thanks for spending time on an informative comment.

[gtstorey]

I think sometimes "why they are there" is because during the reverse engineering HPT figured out (sort of) what they do. I don't think it always means that it has a use. They may have thought it would be useful or not and it may have actually been useful at one time before other tables were unlocked/defined.

[Alvin]

It looks like it spun to me. Hard to make good sense out of it with your log.

If you are seeing RPM's flair between shifts it's almost always low trans fluid that causes that.. Just a half a quart low will cause that in a lot of 4 speed platforms.