TCC (torque converter clutch) unlocking at certain speed?

So I think I ran into a problem with 0.9's torque converter logic.

0.8 never had a problem like this.

With my modded engines, shifting 1-2 (after 1-2 shift TCC is commanded to lockup) --> 3-4 TCC locks up then slips unlocks, shifts from 4-5 then locks up again.

The TCC unlocks once again the continues to slips till a certain MPH then locks up once again?

No problems after the 3rd try to lock the TCC?

 

1600BHP 27xx FT-LB

It has a steep, TQ curve could the rapid change in power "shock" the powertrain?

What doesn't make since is once it lockup the 3rd time its fine and at that point its at, the engine peak power. (more power then when its slipping) est 130 mph

Stop and go WOT again and the same repeats.

i'm around vehicles and tuning, so I can tell when the TCC locks as far, when it locks I have it setup where you can definitely tell when the TCC locks up and unlocks lol.

i'm observing a slow TCC lock up on the third and last try to lockup but once it locks it pulls all the way to redline.

I have noticed when its not slipping (at that certain points) it shifts and lockups to its close real life counter parts.

Overall I love the newer 0.9 TCC logic with reference to OUTPUT speed it acts more realistic than the previous 0.8 TCC logic.

Its just this "slipping" issue i'm stumped on lol.

 

Yup, I'll zip it up and send it in the morning.

Thanks for your help @Diamondback i always like when you comment in threads, always informational .

 

Here's a video of the problem.

 

I haven't played much with converter setup yet, what little I did I could tell there is something which I could not yet tell if it is my configuration or something else.

I was planning to investigate that tomorrow.

 

Is Torque converter lockup looking engine RPM or Torque converter output RPM?
--- Post updated ---
So I get much better results with quite high Converter stiffness, something odd is happening if engine hits rev limiter, shift up does not happen then and lower stiffness allows easier hit to rev limiter, in some cases I might get 2nd gear out of 3 gears stuck forever while engine is banging to rev limiter, turning or easing throttle causes shift up, with higher converter stiffness this happens less as hitting rev limiter does not happen so bad.

Now when torque converter lock activates and you have quite loose converter setup, that can lower torque converter output rpm below torque converter lockup rpm. this can be complicated further with shift points.

I got decent behavior with "converterStiffness":8 when having manually set gear by M2 for example, however on D I got 1st to 3rd gear changes, hitting rev limiter and not shifting while hitting rev limiter, box worked fine on D when setting "converterStiffness":22 but that is messing up how stiff/loose it is on M gears. Luckily I don't need D mode with currently under works mod.

~1400kg over 800hp and 1200Nm of torque, currently I have these set, but some might change and most of the other values still anything but optimal.
"torqueConverter": {
"converterDiameter":0.32,
"converterStiffness":8, (or 22 for D mode)
"couplingAVRatio":0.85,
"stallTorqueRatio":2.05,
"lockupClutchTorque":1300,

So hitting rev limiter does mess something up, but I don't think that has effect to what @Josh is experiencing, but I think that is related to how loose/stiff converter is and converter output speed changing due to lockup, not really sure what other thing he could try than altering converter stiffness and seeing if that can be set stiffer while having still overall behavior he wants.

I would think that 0.9 might need bit higher converter stiffness value than 0.8, but need to test and learn more to see how things work best.
--- Post updated ---
Problem with rev limiter might be that game thinks there being wheel slip, maybe shift smoothing makes this worse, haven't tested that, but hitting rev limiter should result upshift as torque is decreased which usually triggers upshift, however from reasons it might be that it just makes game think there is wheel slip.

 

I use that to get proper shifting feel or with this one vehicle proper tightness or looseness of lock which way one likes to look at it. That value is not yet tuned to final version.

With semi auto for example I have reference videos for vehicle so I can see (well, mostly hear) how tightly lockup really works, so when shifting gears where lockup is active I aim to same harshness, while having gears without lockup to have same kind of looseness that on reference videos, not much science there really, just trying to aim correct experience / atmosphere.

Of course that limits box to be working well only with one torque curve, but price of seeking perfection tends to be high and how possible attempting anything less could be satisfactory

Update: There is still lot to learn with new changes, so need to tamper lot more with things.

 

I guess that is what happens with a Hopper, if you put off road transfer case and 4 speed automatic to it, then set low range, it can be hitting rev limiter quite a lot.

Then comes another problem, when you stiffen TC, it starts to be more like manual box. I'm not sure yet, but change might of resulted situation where we can run into issues, where in real transmission TC output is more accurate signal for shifting, in real box there is also torque that affects shifting (simple non electronic boxes, I will not talk about very modern ones), problem arises when hitting rev limiter, torque goes down and real box shifts up while in game TC RPM might not increase as RPM limiter is keeping engine rpm constant.

With rangeboxes like with a hopper this situation will probably occur much easier as engine RPM change can be so fast that engine hits limiter before TC output is even near where it should then maybe at rev limiter TC output speed is not increasing, but this is just guessing, like I mentioned I haven't looked into it enough.

Stiffening TC cures that symptom of course, but causes other perhaps undesired effects (case Hopper for example, you might not want to have stiffer TC for high range and without offroad transfer case), so I think matter needs more investigation and can't be concluded to either way yet, more studying is needed, there is still other variables that needs to be checked until it can be said that really is the case, but that is just a theory for now.