parking lot surge/stall

[SiriusC1024]

Looks like the TCC is dragging to me. Just try this and log the same way. All I changed is TCC min.

tcc vs rpm.png

[04silverado6.0]

The only change was now my tcc is slipping under load. I had the tcc theory 2 years ago with the 278mm, called circle d and was told that wasnt possible. That is also coming from the guys who sold these 2 converters. I dont mind the idle dip as long as its not a surge or stall. If we can keep it running as it is today id be really happy.

[04silverado6.0]

Same file just another short log.

[SiriusC1024]

Well bump up min. Make spark compensate instead of airflow.

That sonnax part does help btw.

Forgot one thing. It's updated in the file.

[SiriusC1024]

The only change was now my tcc is slipping under load.

It's supposed to slip. 3600 stall remember?

[04silverado6.0]

Shouldnt be slipping while locked. It was noticeable in the seat and on the tach. Check the log.

[04silverado6.0]

Copied everything except the p/n decay table. Ill give it a go tomorrow. Strangely a rev in park does not give any issues and returns to idle normally. Ill see how the new airflow tables act and then dial in the p/n decay. Ive noticed that the throttle follower does not activate every time the peddle is pressed or at least not getting it on the log every time.

[SiriusC1024]

In the log the TCC Slip went to near-zero when the MPH threshold in the tune was met. Below this in 4th TCC Applied was YES, and this points to what Ed was saying about that PID. Again, lockup isn't commanded below 48mph, and in the log lockup doesn't actually occur below 48mph.

Go to 1:35 of tcc 1 log. You'll see what I mean.

lockup mph transition.png

There is slight slipping after that point. See if the latest clears it up.

3rd gear lockup would help a lot.

[SiriusC1024]

You think maybe the clutch in the torque converter is worn from having the min dc set high all this time?

[04silverado6.0]

The trans has roughly 1500 miles just guessing. The fluid is fresh and at the full mark. I always thought it was routine to set the min dc to at least 70-90? This is a single disc not meant to be slipped.

[SiriusC1024]

On the first rev I put in the corvette settings for min as a test. I would increment the shape up a bit at a time, like rev 2, until it clears up instead of setting it to something like 90 by default. Sure, it might end up in the 70s or higher, but you see now that too much does cause problems.

The shape is important. It's scaled with trans temp. Think about viscosity of dex and how it affects pressure. 90 across, or any value, isn't correct. This may be why there was variability in the way the problem happened. Temp-viscosity-pressure.

It's same with a cam and BRAF. Routine to add 20%. You still dial it in.

Keep logging TCC slip. Maybe take notice of the way I've set spark to have more authority over idle in rev 2 so that airflow corrections aren't invoked. You'll get where you need to be.

[04silverado6.0]

I will lower the min dc and see how it does. It should have plenty of pressure to apply with the rpm lvl 6.

[abc]

show tcc lock pid.hpl

I know it sounds like your making progress but I'm not convinced
it has much to do with the TCC as much as all the other changes.

I admit I haven't studied the entire scenario and the whole thread, but I will. I cut a short log of mine that shows the the same PID as yours during TCC Applied "yes" but TCC Mode "apply engage" but not locked. You will see it does eventually show locked. I'm not sure how this fits in just yet, but I will keep following along.

[04silverado6.0]

I dont understand why ive done so many similar combos and not had this issue. The truck norris is the least tuneable truck cam and i can still get those acting decent on a stock verter. Ive done plenty of more wild setups with cheap chinese parts that at least wasnt stalling.

[SiriusC1024]

show tcc lock pid.hpl

I know it sounds like your making progress but I'm not convinced
it has much to do with the TCC as much as all the other changes.

I admit I haven't studied the entire scenario and the whole thread, but I will. I cut a short log of mine that shows the the same PID as yours during TCC Applied "yes" but TCC Mode "apply engage" but not locked. You will see it does eventually show locked. I'm not sure how this fits in just yet, but I will keep following along.

Experience dictates that when you get too far "out in the weeds" you return everything back to stock and start over. You don't continue to add on additional changes trying to fix what you've most likely caused or at the least, made worse.

And when you get to that point again

Maybe take notice of the way I've set spark to have more authority over idle in rev 2 so that airflow corrections aren't invoked. You'll get where you need to be.

[edcmat-l1]

You need to put everything relating to idle back to stock. All the follower and cracker tables, the stall saver RPM, everything. Then you can start determining what needs to be changed to keep it from idle dipping. Even if you make it worse before it gets better.

Your long-term idle trims are still a constant negative.

Heck I'd go further than that. I'd wipe it clean with SPS first if it were in my shop. I start over with just the most basic table changes. Typically when there's a difficult to solve issue like this it's not one parameter that needs changed it's a combination of stuff that collectively causes it.

idle problems.jpg

idle problems 2.jpg

Both of these are your last 2 data logs. Both of them, the throttle blade still looks way too active. The large surge is most likely the stall saver trying to do its job. Need to lower it, put it back to stock, even zero it. Get it out of the way for now.

Put the rest of the idle tables back to stock except BRAF. Then see what ya got.

[edcmat-l1]

Just went back and looked at your specs. What "GEN 4 truck intake"? Gimme a vehicle it came off of. And what throttle body? Matches the "GEN 4 truck intake"?

[04silverado6.0]

2010 lfa engine intake with the stock 3 bolt from the 04 truck. Thought i already had a log with 90% of the idle parameters set to stock or something of that nature.

[04silverado6.0]

So far ive set the min dc to 80%. Had a issue at 4:16 in log 1 where it felt like being rear ended, not sure if it was a lock/unlock event or tcc slip. Didnt have any major idle dip issues so ill get another log on this tune considering the weather is much different this morning.

[Alvin]

Has anyone considered

EIOT
Torque model
Dynamic air settings
Idle pid controls
O2 switch points
copying anything out of some other OS


??????




Just kidding. Go back completely to stock. Work on the absolute basics of the tune. Most of these issues will not be a issue with a rock solid VE table, MAF if you wish, BRAF, and idle timing.




The Min TCC PWM isn't for when the TCC is off. It's basically how fast the TCC ramp applies or not and it does shockingly little.