4L60E Trans Tuning Help

I need some help with tuning on my 4L60E Trans in my 2000 Chevy Silverado 1500 5.3L 4x4. (Mods Posted Below)

1st
It seems all the information I can find on tuning the trans is vague at best or just references the BC Trans Tool (Which was done) The issue I am having is when rolling between 35-45mph and I go WOT it will kick down to 1st gear but I'm almost at my 2nd gear shift point already as the RPMS will jump almost to the 1-2 wot shift point. It really feels like it should be dropping into 2nd and not first. Almost like when you do to down shift on a manual and miss the gear you want and redline the motor

2nd
Having a really hard 1-2 shift at part throttle. It is pretty violent but firm at the same time. At first I thought maybe it was something mechanical in the trans, replaced accumulator pistons fresh fluid and filter change and pulled the valve body to make sure the check balls and everything else was ok. I couldn't find anything mechanically wrong with it, although I know someone has been in the transmission before as it had the nylon ck balls in it and a new plate.

Here is the tune I'm currently working on, if any of you guys with more experience then me can give a few pointers I would greatly appreciate it. I'm working on the VE Table currently and would like to get the trans dialed in a bit better before and WOT Tuning. Trans does feel strong and doesn't feel as if its slipping any. Unfortunately I don't have a log with a WOT run right now to post along with my tune file.


MODS:
BTR Stage 2 V2 Truck Cam
LT Headers/Y-Pipe/Dynomax Exhaust
K&N Cold Air Intake
Yokohama 31.6 tires on stock 16" wheels.

Trans goes to max line pressure when there are MAF codes, you can tell it not to do that anymore.

Attachment 119713

Dude. Your PE EQ ratio is set to .900 - this is Equivalence Ratio, the inverse of Lambda. You're asking for 16.3:1 when in PE.

Lower your WOT 1-2 shift speed (MPH), it's too close to the RPM you have in there.

With your tire, and 3.73 rear, and 3.06 1st gear, your 6250 RPM theoretically gives 51.5 MPH. Calling for the WOT 1-2 should happen 5-7 MPH before the RPM target is met, so that it shifts by engine speed and not vehicle speed. I didn't do the calc for the other gears, but it's your truck, you can do that. https://www.dennysdriveshaft.com/pot...alculator.html

6250 in 1st gear is also cutting it mighty close to what the 60E reverse drum will tolerate.

Thanks for the fast reply, PE is not going to be set at that number. I actually just changed it before checking on this thread, going through the tune I noticed the numbers in the table were not right. I switched them back to what they were, but I'm trying to secure some dyno time to actually get the PE numbers set to something safe. But its proving difficult as the only guy I know with a dyno is around 4-5 months out as he only does it part time. Not sure if I bumped a key or not because the number between the two tune files before this last revision are completely different. That being said, I really appreciate you taking the time to put a second set of eyes on my tune file. It can be really easy to miss something or accidently change something and not notice as I'm sure you've seen many times..lol. That being said, I went to Dennys link and converted the math and made the revisions you suggested. I wont be able to test things out until tomorrow. Whats funny is I have one of their Nitrous Driveshafts in my Comp T/A and never even was aware that they had that calculator on their website. Thank you for the awesome link.

Remember, the potential speed calculator doesn't account for converter slip, so 5 MPH may still not be enough spread to keep from overshooting the RPM target. It's not a problem if you end up going much lower on the MPH to get it to shift at the right RPM.

A log with trans current gear and converter slip will help a bunch getting a solid idea of where it's at.

I have those saved for when I start doing some WOT tuning. Really trying to wrap my head around tuning in lambda right now as well. Copying AFR Err from the scanner and paste multiply by half in the VE Table seems so much easier. But from everything I'm reading is actually not the easiest or most efficient way of doing it. From what I'm reading tuning in lambda can cut the time of street tuning down dramatically. Ill probably eventually 4L80E swap the truck. But thats a few years down the road so I want to get this trans dialed in. Also thought about rebuilding this one with a wider band and some upgraded parts from Sonnax. But whatever direction I go with the build will ultimatly determine what route I take with a trans. Truck will see little to no towing at all.


EDIT: Really wish I knew what was done to the trucks trans before I bought it. All I know is It was a ranch truck from my home state of MT but was very well taken care of. When I first bought the truck a few years ago I noticed the trans was pristine, has a Corvette servo and the tail housing looks brand new among a few other things I noticed without having to remove the entire trans. So im not sure if they had work done to increase the durability of the trans or just had it rebuilt. When I drained the fluid it was a darker red, but didn't smell burnt and there wasn't hardly any material in the bottom of the ban.

You do know you can make the scanner show your wideband in EQ, right? And then you get the same % error comparing commanded EQ to measured EQ, and paste that error data the same way.

I do have an EQ Ratio set up, but its not reading correctly ATM. I'm pretty sure I have something off I just need to find it and correct it. I made the changes you recommended with the trans and the difference in shifting and driving is night and day. I didn't change anything to the VE table between the two logs as it was pretty chilly this morning(Log 12 was AM/Log 13 was PM). I am only applying changes to my VE when the log takes place within a couple degree's of when I first started tuning the VE table which was 65F. But I do have TCC and Trans Slip up in my Charts vs Time on these logs

Quote:

---

Originally Posted by blindsquirrel

You do know you can make the scanner show your wideband in EQ, right? And then you get the same % error comparing commanded EQ to measured EQ, and paste that error data the same way.

---

So I can program at WOT for RPM and it will default to RPM if it is set to shift at a much slower MPH? I'm having trouble with over revving if I hit passing gear 4-3, 4-2, 3-2, 3-1. It won't shift back to the higher gear unless I lift.

Quote:

---

Originally Posted by ninjai_ruken

I do have an EQ Ratio set up, but its not reading correctly ATM. I'm pretty sure I have something off I just need to find it and correct it. I made the changes you recommended with the trans and the difference in shifting and driving is night and day. I didn't change anything to the VE table between the two logs as it was pretty chilly this morning(Log 12 was AM/Log 13 was PM). I am only applying changes to my VE when the log takes place within a couple degree's of when I first started tuning the VE table which was 65F. But I do have TCC and Trans Slip up in my Charts vs Time on these logs

---

Please be patient. I'm 68 years old and I do fairly well but sometimes I get mental blocks.