Performance tuning the 4L60E and 4L80E Transmission VIA PCM

[EagleMark]

The trans cal of the Caddy V4P towing pakage is a sweet setup from factory. Really makes driving a B body more performance oriented. Would be nice in a truck, I think! But trucks are way better then a B body to begin with. So far 0 shift times have been a great improvement to a stock 4l60E trans in truck my old RoadMaster and my 98 Vortec Silverado, although this truck has had the best trans driving I have seen stock!

Since the Caddy tow package bin is a 1994, I'm not sure how it would work in a 1995? 94 to 95 4l60E are differant as the 95 has a PWM TCC! There is also an extra wire on the harness from PCM to trans!

There's also a way to run one wire to a switch for the Performance table to be used in B bodies. The switch only came in one car, the Trans Am I beleive.

Right now I'm playing with TCC lock up times for the driving I do. Seems they want to kick in at speed limit and then I speed up... so I slow down and the TCC unlocks. Got it all dialed in and when Cruise Control is on they are differant? Look in the mask for a 1998 and there's another table for when in Cruise.

Guess my point was there are so many differant tables you can screw things up! Once I had 1 of the 3 speedo scalers off in the LT1 $EE and the trans shifter 3-4-3-4-3-4-3-4 at 75 MPH and my tranny got hot before I noticed it! CEL for hot trans.

Idea for a spreadsheet would be to enter values from all tables and change one so others change correctly. There is a Speedo Calculater in the $EE thread! OBDII TunerCat and EFI live have them built in and can have 600 changes for tire or gear change.

[Cadride]

My truck is a 94, but after comparing the tables between $0D and $EE I'm getting in way over my head. I was hoping that I could use just the info from the performance tables, but like you said what I don't know could kill my tranny.

Did you put 0 for shift times in the "desired shift time vs TPS" mine is currently 1st 875, 2nd 1000, and 3rd 800 at WOT. I have read from different forums that changing line pressure or changing shift times can have the same affect. I would personally think the way you have gone changing the time would be the easiest on the drivetrain components. I changed the MPH that it shifts at under different conditions mostly for the gearing change that I made.

Thanks for the prewarning on the TCC lock up at this point I don't plan to make changes there.

[EagleMark]

I looked in a bin for $0D and I beleive those settings should be .850 and IIRC I did end up at 0 or .100. Sneak up on them, cut in half and see how it feels. RInse and repeat.

When I was plsying with shift times I did lots of data and tranny temps went down a little with short or 0 shift times compared to stock/sluuuuuuussssssshhhhhhhh

[Glen Koenig]

In the thread title you mention 4L80E, and that is why I came in here, to find information about tuning for a 4L80E behind an LT1. However, it looks to me that most of the information is about tuning for a 4L60E. Am I missing something?

I don't want to hijack your thread. Do you know if the 4L60E tables parameters are basically the same as what I would need for a 4L80E?

[EagleMark]

We are trying to get the tips and trick in one thread so good hijack! What are you looking to do? Although transmiossions are differant the paremeters to adjust are similar.

[Glen Koenig]

We are trying to get the tips and trick in one thread so good hijack! What are you looking to do? Although transmiossions are differant the paremeters to adjust are similar.

Sure, I'll explain it all here.

I have been running a 4L80E with a PCS TCU-2000 behind an LT1 (still controlled by the stock PCM (16188051)), in an Impala SS. Conventional wisdom at that time was that an external TCU was the only option for controlling a 4L80E back when I installed the 4l80e. A lot has changed since then, and now I want to go back to the stock PCM for controlling the trans.

I used Tunercat with the CE version of EEB.tdf to switch the solenoid settings in the constants table, and re-pinned the trans connector. It seems to work fine on a short drive around the block. However, I'm very concerned that I not make a mistake by using incorrect line pressure settings, as well as other key controlling tables, in order to avoid burning it up after a few blasts down the 1320. I have a friend that did the swap using TC and he burned up 2nd gear. After looking at his bin file, it looks like he bumped up the line pressure significantly. Might have been his undoing.

Oh I just got a response from Bryan Herter, who said that he uses the same parameters for the 4L80E as he's been using with the 4L60E. So I guess I have my answer, unless you think otherwise?

Thank you,
Glen Koenig

[RobertISaar]

from a control standpoint, there isn't much difference between the 60 and 80, the biggest two things i can come up with are gear ratios differ a bit, so slip calculated would be off without correction, and that the 80 only uses a single TCC related solenoid (PWM) while the 60 uses a PWM and discrete solenoid.

the 80 has the advantage of an input shaft speed sensor, so slip can be calculated better.

the main calibration difference would be the table used for determining what duty cycle to run the PCS at based on desired pressure and trans temp.



other than that, i can't think of much that would need changed. once the trans temp gets high enough, the line pressure is ran closed-loop to help prevent slippage, which is one of the advantages of a PCS equipped transmission.