4L60e fine tuning

[icemaninlv]

The great HP Tuner Forum Wizards,

I am a new tuner but not new to builds, trying to figure out the right mix.
I have a 2007 Silverado Classic 2WD, 3.73. The original 4.8 was removed, and a 5.3 was installed, bored to 5.7, with a truck Norris cam, NBSS intake, and 50-lb injectors.
The transmission is built with a 3k converter, upgraded Vette servo, and pressure solenoids. One problem I may have that may be caused by the build is that the rebuild shop installed an older trans in the truck with the old 93-02 harness, not the 03-08 non-iss harness.

I have an extremely hard 1-2 shift where it shakes the truck with light throttle applications. I can not get that to tune out. I assume its in the valve body the issue.
I have a "bucking" surging in cruise when the throttle is 10% or less like the vehicle is coasting and the lock up is in and out. I believe I have tuned all that out. Please look at log, I did feel it a little but was much better.

Ask ye ol' wizards to look at my tune and my log and point me in a better refined adjustment.

Thanks,

Mike

[enmanuelpimentell]

Did you try to increase the shift time at a light throttle zone? You could test if that compensates the hard 1-2.

[blindsquirrel]

Corvette servo is very large, Sonnax has one that's inbetween stock and the Corvette. Increasing the shift time is just going to add more slip (and heat, and wear).

Raise the Trans Torque Management way up (like 60%-70%) in the range where it's shifting too hard, see if it responds to that. This will drop spark timing during the shift while letting the trans shift in a normal amount of time.

[blindsquirrel]

https://www.sonnax.com/tech_resource...for-the-4l60-e

[edcmat-l1]

It's just a good idea overall to try and fix a hard shift created by a shift kit, larger servo or both. Take it to the builder and tell him you want it calmed down.

[icemaninlv]

It's just a good idea overall to try and fix a hard shift created by a shift kit, larger servo or both. Take it to the builder and tell him you want it calmed down.

Yeah, my builder is 90min away. He is tracking my issues and going to miss with the valve body, but I was trying to avoid the down time and see if I could tune it out.

[icemaninlv]

Did you try to increase the shift time at a light throttle zone? You could test if that compensates the hard 1-2.

I'll try that tonight.

[blindsquirrel]

If you make the shift too long you'll get a double-bump shift. The right way to do this is
1. Something other than the Corvette servo
2. More torque management at the shift.
3. Or both 1 & 2.

[Alvin]

The accumulators are often messed with too. You can't really undo a shift kit with tuning.

You can try absolutely stock shift pressures in the tune first if you haven't already. But don't go less than stock pressure.

[ns158sl]

Need to log torque. MAF needs to be calibrated closer. Do you have a stock as read tune for the truck?

[DB5249]

give me like 40 minutes, i can probably fix it for you in tune. I probably have more trans tuning time than most of the guys on the forum. i just don't post much

[DB5249]

based on year i am assuming you are using a 4l70e

[Hondaeater]

You might try to put the table back to stock,
Engine>Torque Management>General>Spark retard vs Torque reduction spark is 0 so no matter what you enter in transmission torque management table it will not have any reduction.
If this "bucking" is happening at 1200-1400 RPM, you have a big jump between these cells in timing in hi and lo octane tables. Not sure what pedal position is at the time of bucking...
You have the TPS% channel but need to log Accelerator pedal position SAE. If pedal is at 1.19% or 1.89%... try lowering the Base min TPS% so it does not go between idle and main spark tables.

Log channel for Base spark and Idle advance. If you are transitioning between those idle and base tables then the over/underspeed tables are intermittently active. You need to log those channels and may show that happening during 10% and below. Not really enough data in your log, but something to consider.

[DB5249]

07 Silverado final Revision.hpt here you go bud. perfect trans shift for your set up, log it and we will adjust shift pressures and so on time next

[Hondaeater]

So your tune has the downshift higher than upshift speeds....
Iceman I would look over this tune before using.

[Hondaeater]

Attachment 160586 here you go bud. perfect trans shift for your set up, log it and we will adjust shift pressures and so on time next

Perfect trans shift... hmm

[DB5249]

if you knew what you were looking at you would see the trans strategy but you don't seem to know anything about trans tuning so i can explain if need be

[DB5249]

the base normal trans tune is good to prevent early kick down only allowing trans to kick down above 70 percent throttle and kick down is only allowed to occur if rpm don't exceed 4800 rpm based on his final ratio of that gear. if you look at the performance shift table, which on his truck is the tow/haul switch same concept applies except it allows for a more aggressive kick down above 50 percent throttle. converter tables for apply and release are also optimized to have the trans shift in lockup perfectly.

[Hondaeater]

if you knew what you were looking at you would see the trans strategy but you don't seem to know anything about trans tuning so i can explain if need be

Please share your thoughts. I am open to hear it! I am not a trans guy, sure would like to be someday though.
thanks.

[Hondaeater]

How does 12% TPS for upshifting 2-3 at 19mph but then the downshift 3-2 at 37 supposed to work? I really would like to understand this, this is 1 TPS example but the table is set up like this. Thank you for sharing!!