2014 C7 6L80 Unlocks on 2-3 WOT shifts

[Asd_srt]

Been fighting an issue on a 2014 C7 Corvette 6l80 (OS 12660065). I know the Caprice PPV and SS had the same issue for a little bit, but with the flash of the Camaro 6L80 Transmission OS it would fix it, and now with the latest updates giving up desired pressure and apply ramp tables seems to fix the PPV/SS Sedan issue. However, with 2014 C7 6l80 I can't get a converter to stay locked on the 2-3 shift. I don't have this issue on my SS or C6 6L80 car the converter does exactly what I tell it to do on those cars. Same for the 8 spd c7s. The 6l80 C7 just seems to have something going on causing the converter to unlock that I can't figure out.

I've done a lot of C6s, 5gens, 6gens, and 8 spd C7s that all lock and hold fine. This is the only car and OS I feel like something is off on. Not sure if it's something I can't see that Hp Tuners doesn't have access to in the torque model or some weird table causing this that we can't see on this OS.

I've gotten it to lock a lot faster and better but every 2-3 shifts no matter what it unlocks. It also never fully locks it's always showing around 100rpm of slip which is also weird for every other car I listed above when it locks it locks. I'm wondering almost if the issue is the transmission itself having an issue supplying the actual pressure to lock.

The converter lock tables overlap so it's not that the file has 3rd to lock at 110mph. I've moved the command lock MPH all over thinking maybe something with this os needs it to be close or further apart between the shift and locks. That had no change on how it locked. The car makes the 2-3 shift and around 10mph after the shift it will command the converter to lock VIA TCC line pressure. I started off with the BlueCat transmission tool for all the lockup tables which has always worked on every other OS and I just fine-tuned it at the track for the best ET results. But even with that still didn't work.

OS 12660065

dave 2-3 unlock.png

[Asd_srt]

Update, with commanding the lock on the scanner it locks and holds 0 slip. Doesn't unlock on the shifts, Just no idea why it wont fully clamp on it's own.

[dwhst9]

Hoping someone, somewhere has a solution or i'm gonna just click my mouse and lock than dang thing lol.

[hjtrbo]

Fuck all we can do for you without a tune to look at to verify your settings.

[blindsquirrel]

Fuck all we can do for you without a tune to look at to verify your settings.

Pfffft, you should be able to take the screenshot, decompile it into individual bits, say the magic conjuring words ('Enhance, enhance') and end up with a raw binary that can then be saved with the right extension, thus recreating the tune file it came from. I mean, they do stuff like that on TV, right?

[Asd_srt]

it was more a question of this specific OS (ECM OS 12660065 TCM OS 24270599). I've talked to a few people who've all had the same issue on the same OS. I've tried more settings on this than any car. All the settings still had the same thing 2-3 unlock. I didn't post settings or the tune because it's had 20+ tunes flashed all with the same issue on this one car.

Meanwhile every other 6l80 car I've touched locks and holds fine. I started with the settings that work without issue on TCM OS 24267577 those didn't work so I've gone all over the place changing settings every which way trying everything and it doesn't work so far.

Current settings on the car. As stated this is the only 6l80 I've had this issue with. Plenty of cars that made more power and went a lot faster than this one that I've done the converter works absolutely fine with looser and tighter converters. Even the same converter just on a C6 works perfectly.

Current settings that seem to work the best but no matter what unlock on the 2-3 shift. Apply ramp didn't seem to have any change no matter the settings. Desired pressure helped lock it sooner and better. But still unlocks on the shift.

current dave tcc.png

Current MPH lock settings. Also Moved these all over to see if it helps thinking maybe this OS was more sensitive. Still nothing. This car seems to have a 10ish mph delay on the lock mph. Where my C6 and Chevy SS sedan seem to lock instantly off mph and there's no delay on those.
dave tcc speeds.png

ECM OS 12617631 TCM OS 24243170 (Ls3 C6) with these settings work absolutely fine and on a faster car with a looser converter too. I've tried the same settings for the TCC adapt as both my SS and C6 have thought maybe that was the cause and no luck there. C6 settings pictures are below.
my tcc settings.png

The only thing I haven't tried is flashing one of the TCM OS from an LS-based car that I know works onto this. Wasn't sure if that would work on this being a Gen V flashing Gen IV OS.

Am I just overlooking something on the off year mix of LT1/6l80 on the 2014 C7?

[RC1]

Just a quick observation from a rookie, but are you sure that the TPS% is staying WOT (84%) when this happens? I see you have the pedal in the logs but no TPS.

[dwhst9]

Just a quick observation from a rookie, but are you sure that the TPS% is staying WOT (84%) when this happens? I see you have the pedal in the logs but no TPS.

Yes, it's WOT

[Asd_srt]

Just a quick observation from a rookie, but are you sure that the TPS% is staying WOT (84%) when this happens? I see you have the pedal in the logs but no TPS.

Yes, I've changed that completely with no luck. Even setting it at max tps to 0%, 1%, 10% and it was still unlocking. I haven't messed with it recently with the current desired pressure settings.

I can mess with the adapt settings some more to see how it helps with my current desired pressure settings. Maybe it was one of those everything was working against it on this OS.

I'll max everything out on the adapts so there's no possible way it can come on and see how it helps now.

[RC1]

Yes, it's WOT

Is this one of those tunes and logs that is top secret? The guys had previously asked for the files to try and help out.

[hjtrbo]

Yep, must be. There's another table you haven't touched yet and maybe another 1 as well. No guarantees it'll work but it's your last dice before swapping OS's.

[dwhst9]

Is this one of those tunes and logs that is top secret? The guys had previously asked for the files to try and help out.

This is for a N/T aka grudge car. I do not want to share his intellectual property on an open forum w/o his permission. I do appreciate any help & insight that is provided here, however!

[blindsquirrel]

If you can't post the files in a public forum then a public forum is the wrong place to look for help

[Asd_srt]

If you can't post the files in a public forum then a public forum is the wrong place to look for help

I'm just trying to help them dial in the converter. I didn't tune the car, I think that's where the issue could be. What other tables need to be shown for a lockup other than lockup tables?

If I tuned the car I'd post up the file, but also as I've stayed I've never had this issue on any car I've done all the tuning on. But I've also never needed to lock a 2014 C7 in 2nd.
Lesson learned don't ask for help about a specific OS and don't help people tune cars. I won't make that mistake again.

So I guess my question is (as stated in the first post) on a 2014 C7 (ECM OS 12660065 TCM OS 24270599) who has the converter locking in 2nd at WOT and staying locked? This is an issue only with the (ECM OS 12660065 TCM OS 24270599) that I've had so what other tables would you like to see?

[BigMike42]

Fighting the same issue on my 2016 c7 it will stay locked until 4th then it will unlock. I lose 4 mph and 2 tenths when this happens

Tried removing all the adaptives and continues to happen

[STAGEUP]

Strange, I've done a few 6l80 C7s with OS 12660065 making 900+ whp, with WOT lockup starting in 2nd without any trouble. What converter is it?

[dwhst9]

Strange, I've done a few 6l80 C7s with OS 12660065 making 900+ whp, with WOT lockup starting in 2nd without any trouble. What converter is it?

We have a custom spec?d Circle D converter,. As stated before, I can lock it with the scanner in 2nd and keep it locked through 3rd, but it refuses to do the same from within tune.itself.