ZF8HP70 fails 1>2 shift under WOT

[shak3r]

@james1595 I noticed throttle control was primary means to pull tq, which is very slow. Best to only use spark.
Engine > Torque Management > General > disable ETC. Re-enable Spark in ESP section for safety.

Recommend logging "Throttle Torque Source" which will show when you are hitting a rpm limit.

Log TCC Mode (vs TCC Locked) which shows all states.

I think the key in all of this is to get the TCC locked as soon as possible.
I noticed in my successful shifts the TCC goes Open > Apply Fill > Apply Comp > Slip SS > Locked > Overlocked all PRIOR to Trans Commanded Gear = 2.
Your logged TCC Locked says simply "No" prior to you letting off the pedal.

We need more info on tuning the TCC for all this to happen prior to commanded shift!

[james1595]

I do have spark torquemanagment, but as you can see, it doesnt work for 1st gear for some reason. Also i thought i had the throttle source pid active, ill get that fixed, but it was hitting the rpm limit. As for the tcc, ill make that change and do another log. But, it ahouldve locked in first sense its commanded to, so thats kinda wierd. Ive been told my convertor could be bad, but thats just a guess from a few people.

[LilSick]

Best to only use spark.

Not if it's quit shifting. Using spark only is not how i fix em. But that does not look like his problem here anyways. Not to me. I would be logging different pids if i were tuning this

Why are you afraid to pull fuel James?

Nice burnout

I see some issues and think i can help you fix the shifting problem

I do not believe the clutches in yer convertor are bad but would need a log (with traction) to know for sure

Did you lift off the pedal for a split second top of 3rd there or did the pcm do that or is your D pack shot or what is going on there??? I would be more worried about that than anything if i were you. Looks like it hooks, then there is some serious internal slippage, 1000 rpm flare. Need additional pid's.

*some traction would not hurt either ha

[james1595]

I lifted in 3rd because i was starting to drift. As for the fuel, i turned it off to see if i could get it to pull timing for the shift before it pulled fuel, but it did not. And ill log some additional pids for the convertor as well

[LilSick]

oh ok, then it shifted into 4th and you got back in it and it tried to downshift back into 3rd

but only for a split second before shifting back into 4th

i see it now

this is why having traction is important

effective pedal position does not hurt either

*throw in a front wheel speed so you can see spin too

[shak3r]

@james1595 maybe try lowering the OSS rpm speed for when the TCC locks in 1st gear. I think it would be table 46813 for shift id = 5
i.e. 290 x 3.07 = 892 OSS rpm (approx 5040 engine rpm)

You may need to reset Adaptives if making those changes. I'm not saying those are optimum values, just trying to see if it can force a shift.

You should also log Accelerator Pedal Position (not just throttle).

TCM_46813.JPG

[james1595]

@james1595 maybe try lowering the OSS rpm speed for when the TCC locks in 1st gear. I think it would be table 46813 for shift id = 5
i.e. 290 x 3.07 = 892 OSS rpm (approx 5040 engine rpm)

You may need to reset Adaptives if making those changes. I'm not saying those are optimum values, just trying to see if it can force a shift.

You should also log Accelerator Pedal Position (not just throttle).

TCM_46813.JPG

would the oss be based off of gear ratio, not rear end ratio? also i have no other torque converter pids. all i can see is if its locked, slip, and unlocked.

[shak3r]

Not sure what I was thinking but you are correct, 8HP70 Gear Ratio 1-8: 4.71, 3.14, 2.1, 1.67, 1.29, 1, 0.84, 0.67

However if u do the math (i.e. 290x4.71) it don't jive with what is seen in logs. There must be some kind of multiplier. I recall having this discussion before so I'll search my notes.

Update: Notes suggested to divide OSS (i.e. table 46813) by 0.6 for gears 1 & 2, then multiply by gear ratio. Not proven IMO so take this w/ a large helping of salt!

[james1595]

ok, just wanted to make sure i wasnt crazy. also i found the pids. had to connect to my car and repoll for supported parameters and found them.

[shak3r]

The more I dig the more confused I get. Let me explain...

If you compare a stock Scat vs 1320 tune file you will notice they actually INCREASE the TCC apply/release speed.
Recall the 1320 has a higher stall (2350) converter than a Scat.
If anything I would expect them to lower the apply/release speed so not to overshoot the RPM limiter.
The only other significant TCC change is they lower table 26140 max slip allowed. But I'd be cautious to change that or risk burning up your converter.
Having said that, I'd consider lowering 26140 & 26149 a bit to see if shift reacts accordingly, while logging all those PIDs.

[james1595]

Alright, ill give a shot

[james1595]

so i added some additional pids for the Transmisson and convertor and did a little driving around. noting extreme. you can see it use torque intervention to try and get it to shift, but it still took a long time, and the E solenoid taking a long time to fill
2-9-2024.hpl

[shak3r]

Your logging the right PIDs now but that looked like a Sunday drive. TCC locked up early (a good sign IMO) but you barely broke 4k rpm, so not near a WOT pull.

[DodgeBoy_8HP]

True... not a WOT drive.
Also, A LOT of vibration and shutter right after upshift and coasting. Some light flares and under filling on downshit

Definitely some room for improvements.

[james1595]

I was just logging to make sure all the parameters were logging correctly, and to see what it was doing. It seems to be trying to shift, but having dificultes getting the torque to match in the lower gears

[LilSick]

james1.2b.PNG

james1.2c.PNG

james1.2d.PNG

here is one that was not shifting that i got to shift ON THE STREET : )

SPARK ONLY

car has a convertor too

3250 stall

you can clearly see i have the converter unlocked

lemme find a pic of what it was doing when dude brought it here...

[LilSick]

Attachment 142780

straight into the limiter

closed throttle

pulled fuel

(and timing)

problem solved : )

[shak3r]

Calling BS on some of these vaguely worded posts that don't offer real or potential solutions. Sounds more like solicitating for biz instead of offering help this forum was designed for.

[LilSick]

ummm

vaguely worded?

you lack power

you cannot tell others how to speak

i mean you can try...

but you will not be successful and it would only lead to misery

your own misery

make it a great day : )

[shak3r]

@LilSick sounds like you've had good luck by leaving all TqMgmt options enabled (spark/fuel/throttle). Why don't you just come out and say that instead of "I see some issues and think i can help you fix the shifting problem"?

I'm the OG of this thread and we are now nearly 6 pages deep w/ no defined solution, but plenty of so-called internet mechanics that "want to help" (w/ a fee of course).