New to HPT - Need some 6L90 Help

[Turbo Ryan]

Hey guys,

Im new to HPT. Im lucky enough to have a good friend who is very tuning savy. But I feel bad bothering him everytimne im OCD'ing about my truck.

I have an 07 2500HD 6.0/6L90.

Engine is stock with just exhaust. Trans is fresh and has a Circle D 258mm multi disc that stalls about 3200.

I have had issues with a 3rd flare since I bought the truck. I took the trans out and replaced the stator and 1234/35R clutch assembly with updated parts.

Though its much better, it still has an occasional flare into 3rd. most noticable if your increasing throttle angle while its shifting.

Ive pretty much only moved some shift speeds and throttle angles in 5th and 6th and massaged the converter on/off to my likes. Im very happy with the current strategies. No longer shift busy on freeway hills and no longer sluggish do to the converter pulling the engine out of the powerband.

So....Where do I start to correct the 3rd flare?

And....Id like to converter to lock a bit firmer than it does, with a little bump.

Thanks in advance for any information!

Ryan

[Area47]

whats the trans temp when it flares?

[Turbo Ryan]

Well, Im in the northern states and have a Tru Cool 40K.

It runs a whole 100-110 righ now warm with ambient below 30* F. I know thats not ideal. But I do not put alot of miles on it in the cold. Its never less than 100 when driving warmed up. I used to run a cooler with a cold weather bypass and had temp issues when warm. I have read of other people having issues with the trucool setup with the bypass as well. I did on my SD. So I voted for simple and reliable.

Seems to do the flare pretty much any temp at this point. You almost feel the truck lose momentum on the 2-3 shift very frequently, even if you dont feel a flare. You just feel a momentary sluf in accelleration. IDK how else to explain it.

Before it was consistent per the GM TSB around 110 but would do it at any warm opperating temp.

I replaced the parts I did because of the bulletin. The problem was ideltical to the bulletin description. I figured id put a real converter in while it was apart. Something with a stall to get this 6.0 in the power easier. I could not be happier with the results of the converter.

Im a 4L80 guy, so this transmission behaves much different than I like and am accustomed to. Were getting it ironed out, but the clutch to clutch transmissions just feel defferent!

Thanks for any input!

Ryan

[edcmat-l1]

Post a tune and data log.

[Turbo Ryan]

Post a tune and data log.

I need to work on and learn the data logging. I can post the tune later today.

The only thing that has been changed from the base tune is some shift speed and converter startegies for 5th and 6th. And the required changes on the slip tables and such for the stall. And most or all TM removed.

Ill get that up tonight. I could not figure out how to log it. Ill try to do that tonight so I can log it on my way home. I have a county road with some stoplights that run it through the 2-3 shift 3 or 4 times in 3 miles. Hopefully it will act up.

Thanks!

Ryan

[Area47]

I need to work on and learn the data logging. I can post the tune later today.

The only thing that has been changed from the base tune is some shift speed and converter startegies for 5th and 6th. And the required changes on the slip tables and such for the stall. And most or all TM removed.

Ill get that up tonight. I could not figure out how to log it. Ill try to do that tonight so I can log it on my way home. I have a county road with some stoplights that run it through the 2-3 shift 3 or 4 times in 3 miles. Hopefully it will act up.

Thanks!

Ryan

the ideal temp for the 6l series is 120-180 degree's. 180 is not going to hurt it.

plus, i bolded part of the problem.

[Turbo Ryan]

the ideal temp for the 6l series is 120-180 degree's. 180 is not going to hurt it.

plus, i bolded part of the problem.

I was planning on putting some back as I was told you can limit it instead of remove it. Ill look into those tables this evening!

Ryan

[Turbo Ryan]

Well,

I was making some small shift speed/tp changes so it will stay in 6th and locked easier on hills at higher speeds, I messed up and clicked save rather than save as.

Ill have to go read the tune in the truck to post what is on it now. Its minimally different with just different 6-5 ds speeds and a bit different converter lock/unlock in 5th and 6th.

Im still taking notes and looking at multiple tables making sure everything jives. It behaves well with the tune that's in it now other than some 3rd gear behavior problems, and id like a little more throttle before 6th unlock happens, and the 6 to 5 ds. The tune im posting should address that.

Im going to make some 3rd shift logs tomorrow on the way to work. Ill post those when I get there.

Heres my tune. Please don't tease me about the 5th and 6th stuff and converter stuff. Im learning!

Im open to criticism on the transmission tune.

Ryan

[Turbo Ryan]

the ideal temp for the 6l series is 120-180 degree's. 180 is not going to hurt it.

plus, i bolded part of the problem.

Also, im expecting it to run 130-140 once the warmer months come. Which is perfect in my mind. It hit 110 today at 35 degrees outside in stop and go. It used to run 175 almost non stop with any trailer behind it and a stock converter in tow haul. It would cool to 140-150 on the highway until it got shift busy, then right back up. Im not afraid of the heat, just haven't had luck with stalls and big coolers with cold bypasses. Ive had 180+ summer temps with a bypass in my GN, removed it and was down to 130. Same on my Super duty with an ATS multi disc. The told me I needed a bypass with the tru cool. That thing would wing over 200 with ease, removed the bypass and it never passed 150.

[Turbo Ryan]

Another thing id like to look at is if there is a way to keep the converter locked with no throttle between certain paremeters. Example would be lifting off the gas on a freeway decline at say..70 mph. The converter unlocks, with this stall speed theres a pretty big revup when you step back into the gas, its momentary then it goes back into lockup right away. But none the less, its annoying.

I have 2 notable freeway hills on my commute, and alot of lifting off the gas pedal. So it does this frequently.

Maybe it just is what it is?

Ryan

[Area47]

change the lock and unlock speed vs tps in the tcc settings. last 3k stall i did in a 6spd truck stayed locked when i dropped the unlock speed in 4th-6th. takes a bit of tweaking as well on your end to see what you like in this aspect of it. you can also get the lock up to feel stock as well with some tweaking.

[Turbo Ryan]

Awesome, Ill look into that. It would "flare" the lockup, a notable slip once you got under 2% throttle untill I made a change to the min TPS. That corrected that issue. Were getting there. It will be worth the work.

[8850]

Try this...

[Turbo Ryan]

Try this...

What will this do, so I know what im doing/looking for?

Thanks!

Ryan

[8850]

What will this do, so I know what im doing/looking for?

Thanks!

Ryan

Makes for good clean shifts at least with my Corvette.

[Turbo Ryan]

Ill dig into that and try those changes.

I need to figure this 3rd flare out. Its irritating at best. Ive been driving it alot the last week, it does it alot. Ill try adding some TM. Im going to log the shift to determine when in the shift its flaring so I can make the needed adjustments. It only 3rd, all other shifts are crisp and consistent. 3rd just has a sluffy feel all its own. Prob. just need to make some small oncoming adjustments.