Slugerado Harsh shifts 6l80e

[Cpwood]

Been struggling for too long with trying to control the hard shifts on my silverado. Mild build LY6, newly built 6l80e (billet bell housing, shafts, and updated clutches), new posi gears. I've gone back to stock then added 10% shift pressures, tried many different torque management settings and been just reading anything I can find for the last year. But ultimately I feel more lost than when I started. I've attached my tune and a log from today (26min, 41min in 2-3 shift slapped hard) I'm afraid I'm getting close to winning or blowing something up. Really hope someone smarter than me can see what I'm missing here.Slugerado Trans hard shift WOT.hptslug shift hard 2-3 shift end.hplslug shift hard 2-3 shift.hpl

[Alvin]

Don't chase shift feel with pressure on a 6l transmission. Put the shift pressure back to stock and adjust the desired shift times and all the shift time adders.

[Cpwood]

So transition time and torque adder tables under upshift first? And set everything else back to stock transmission settings?
hjtrbo said before "the initial table is the jerk and final table is the actual acceleration. Just a theory" If this is true and I'm getting too much jerk increase the intitial table to lower the slap?
Today on the drive, in mexico, I was able really run through the gears but 2-3 is starting to settle down but still jerks harder than I want in a heavy truck.

[Cringer]

Been struggling for too long with trying to control the hard shifts on my silverado. Mild build LY6, newly built 6l80e (billet bell housing, shafts, and updated clutches), new posi gears. I've gone back to stock then added 10% shift pressures, tried many different torque management settings and been just reading anything I can find for the last year. But ultimately I feel more lost than when I started. I've attached my tune and a log from today (26min, 41min in 2-3 shift slapped hard) I'm afraid I'm getting close to winning or blowing something up. Really hope someone smarter than me can see what I'm missing here.Slugerado Trans hard shift WOT.hptslug shift hard 2-3 shift end.hplslug shift hard 2-3 shift.hpl

https://www.youtube.com/watch?v=1-OF...VeoqDl2MvjEnZy

[Cpwood]

Thank you I've been searching for something just like this.

[TheMechanic]

https://www.youtube.com/watch?v=1-OF...VeoqDl2MvjEnZy

This is a great set of videos. Watched them all last week and it is the "aftertreatment" for BlueCat. Love it if you could make one of your programs that will do all of the rest of the pressures that BlueCat doesn't. Currently BlueCat is the only game in town and hasn't been updated in about 5 or 6 years I think.

[Cpwood]

Cringer,

Here's what I took from you videos. But I am stuck with a 3-2, 2-1 lurching downshift. Also 2-3 upshift hits really hard at WOT and is 50-75 mil sec, no bueno for this big truck. Hopefully you can see where I went sideways.

2-3, 2-1 downshift issue and WOT hard 2-3 upshift.hpl

Slugerado trans vve final.hpt

[Alvin]

But I am stuck with a 3-2, 2-1 lurching downshift.

Typically this is a shift pattern problem. The downshifts need to be timed with the idle RPM so its not pulling the engine all the way down and lurching forward when it does downshift.

[Cringer]

Cringer,

Here's what I took from you videos. But I am stuck with a 3-2, 2-1 lurching downshift. Also 2-3 upshift hits really hard at WOT and is 50-75 mil sec, no bueno for this big truck. Hopefully you can see where I went sideways.

2-3, 2-1 downshift issue and WOT hard 2-3 upshift.hpl

Slugerado trans vve final.hpt

Questions:
After flashing your updated tune, did you do a reset & preset on the trans? Then drove it around for a while to allow it to learn at low throttle inputs before going WOT?
You have aftermarket clutches? The fill volumes still look stock though.

Suggestions:
Did you change the virtual torque? I did a compare against the other three 2011 silverados and your airmass values are different. I would suggest putting this back to stock for now if you changed it.
The Shift Timing > Upshift> Transition Times also appear to have been changed, I would revert those back to stock.

[Cringer]

Cringer,

Here's what I took from you videos. But I am stuck with a 3-2, 2-1 lurching downshift. Also 2-3 upshift hits really hard at WOT and is 50-75 mil sec, no bueno for this big truck. Hopefully you can see where I went sideways.

2-3, 2-1 downshift issue and WOT hard 2-3 upshift.hpl

Slugerado trans vve final.hpt

Oh one thing I forgot to mention...discrete shift torque.
You should disable this for 2-3 (set the value to 0) as a test.

Your current settings right now are say is "if you are making at least 295 ft/lbs, then round up to 500 ft/lbs, to use as a look up on the base shift pressure tables." This is a lot of torque, so the trans will a corresponding amount of higher pressure. By disabling it (setting this back to zero in [TCM] 15920), you are saying to interpolate base shift pressure on actual predicted torque. This also ties back into you virtual torque tables I mentioned before.


I05iw9z.jpg

[Cpwood]

Any time I flash new trans stuff I reset adaptives and drive nicely for awhile. Yes aftermarket clutches but didn't understand or know where to start with fill volumes.

Yes the 6l80etuning.com guy had me change the airmass by 5% so it matched my dyno run. Peak torque was 450 to the wheels at 4800rpm. This was to allow the trans to adjust to the increase in power. I don't have user perimeters unlocked yet so it was the only way I could affect the virtual torque tables.

[Cringer]

Any time I flash new trans stuff I reset adaptives and drive nicely for awhile. Yes aftermarket clutches but didn't understand or know where to start with fill volumes.

Yes the 6l80etuning.com guy had me change the airmass by 5% so it matched my dyno run. Peak torque was 450 to the wheels at 4800rpm. This was to allow the trans to adjust to the increase in power. I don't have user perimeters unlocked yet so it was the only way I could affect the virtual torque tables.

OK if you cannot get the fill volume info then, you will have to let the adaptives figure it out on their own over time.

In the meantime, I would suggest disabling discrete torque for 2-3. However, I am not sure how necessary it will be to reset/preset the trans with this change. I would say you should reset/preset to be on the safe side though.

[Cpwood]

Did disable the discrete torque in 2-3 and did the reset just to rule it out. Dropped the 2-1 to 2 mph at under 25% throttle and it seemed to help at first but as I got close to the end of my drive home the adaptives started to overcome the gentle roll to a stop and 2-3, 2-1 started to jump 300-400 rpm. I started going down the rabbit hole of oncoming/off going volumes and now my brain hurts. Now I can't make heads or tails of it all. Did find someone dealing with the lurching and chased many things until he lowered the airmass 20% below 900rpm. Not saying that's what I need to do but it does corelate to what you were saying about returning the airmass to stock. Then approach the oncoming and off going volumes. Ultimately my knowledge needs to expand a bit more on reading flares and binding, so I understand what they look like. I can feel major ones but reading the little variations has me lost

[Cringer]

Did disable the discrete torque in 2-3 and did the reset just to rule it out. Dropped the 2-1 to 2 mph at under 25% throttle and it seemed to help at first but as I got close to the end of my drive home the adaptives started to overcome the gentle roll to a stop and 2-3, 2-1 started to jump 300-400 rpm. I started going down the rabbit hole of oncoming/off going volumes and now my brain hurts. Now I can't make heads or tails of it all. Did find someone dealing with the lurching and chased many things until he lowered the airmass 20% below 900rpm. Not saying that's what I need to do but it does corelate to what you were saying about returning the airmass to stock. Then approach the oncoming and off going volumes. Ultimately my knowledge needs to expand a bit more on reading flares and binding, so I understand what they look like. I can feel major ones but reading the little variations has me lost

So is 2-3 now working?

Your OP says "Mild build LY6". So I am not sure what all that entails, but I would suggest returning virtual torque to stock...then...
either leave it stock and see how it drives...
or...
Add the 5% to the airmass to the bottom row and interpolate to the top row (rather than adding 5% everywhere and upsetting the lower airmass rows with more torque).

Also I am not sure how only setting the airmass torque and leaving the MAP torque alone will impact things. You might need to alter both to keep them in balance.

[Cpwood]

Yes 2-3 settled down, but didn't go full ham yet. I'll send it on the way to work in the morning.
I think you're on to something with the interpolate down the 5%. Just a bummer to run VVE and MAF again

Mild to most of you guys with boost.
about 10.5-11.0 : 1 compression
799 heads mild port, increased intake and exhaust, .625 lift springs, 63cc
New FIC matched 50lb injectors / 445cc
420whp @5500rpm
450wtq @4800rpm
New built and beefed up 6l80 new billet custom stall about 2200-2600
3.73 posi

[Cpwood]

Well the slug did pretty good today up against a TRX on some country back roads (in mexico). Still hits 2-3 and chirps the tires but it was worth it to walk away from him after every corner. I think he might be taking it back to the dealership, if he only knew I was fully loaded 8' bed with tools in the back. Also found out I need some better calipers got some scary brake fade and saw the trans temp climb to 180 so I backed out.

[TheMechanic]

180 is perfectly fine for trans temps after a pull.

[Cpwood]

I thought it was still in the good range but heard from the old guy crowd thet dex VI starts breaking down over 190. Never really did my own research so not sure how true or how long over 190 would cause the juice to break down.

[Cpwood]

Little update from the transmission builder that may help those in the know with what he build the transmission with. New OE bell housing with pump and gfx pro rotor kit, transco shift kit with valve and spring kit, GPZ HD clutches . He said he left all the stock distances for the clutches with all new wave plates, billet input and output shafts and forgot what he said about the drums. This is all Greek to me but maybe this helps narrow done why 2-3 upshift is chirping tires and hitting 75 mil sec.