Need an opinion and help on the pressures/ slip of new tranny. Files attached

I'm in the process of learning tranny tuning. I've just installed a new completely built 4l65 in my car and attached is my first log driving it along with the tune. I'm confused about some of the data. How do Input shaft revolution and output shaft revolution work, mine seem to differ in the 1100 at WOT in second and showing 175 to 200 TCC Slip @ 5500 rpm. Is the offset in input to output the gearing difference for 2nd?

I believe I've read < 10% slip is good? Is that a good figure to use?

The highest I see my Pressure Control Solenoid Pressure go to is 90 psi I thought it could go to 96 psi. Do I have something adjusted wrong in the tune?

Is there a PID or way to Log Line Pressure can't seem to find that.

The car has been scaled 20% to stay under the g/sec limit. I understand this can mess with the torque calculations for tranny pressure.

The log shows a short WOT run at 360 and a longer one at 5400

Thanks for the help

TCC slip depends on when the TCC is locked.

TIS/TOS will have a different ratio depending on the current gear.


We need to see these pids:
GM.TCCMODE
GM.GEAR

Also, add this pid:
GM.SHIFTLAST

You can then drop these pids:
GM.SHIFT12
GM.SHIFT23
GM.SHIFT34
GM.TCMSLIP <--- ( keep GM.TCCSLIP )
GM.TFMCUR
GM.TFMDES

Thanks for the help, I'm going to the track this weekend and will add the PIDs you suggested. I'll follow up with some logs.

Try those pids on the street first, before you go to the track.

~ posted by phone ~

At the 1/2 mile race this past weekend I made a few runs with my converter unlocked and 1 locking it in 4th at 150. MPH were about 3-4 higher unlocked in the 1/2, I can't attribute that necessarily to the locking because my 1/4 mph was slower on the locked run by about 4 mph (the 150 lock speed came after the 1/4 distance) and I played with tire pressure and timing a few degrees each run.

Locking the converter did take my rpm from about 5750 down to about 4750. That caused my MAP to go from 219 kpa to 182 kpa or I lost about 5lbs of boost as soon as it locked. From what I see in the log, the converter locked solid right away.

I did not try locking it again after looking at the boost I lost given I had limited runs. I would have liked to try locking in 3rd and 4th, maybe next race. I was concerned about the shift from 3rd to 4th being locked, I don't know enough about tranny tuning to be certain how that would work, is there enough time to unlock before it shifts to 4th...

I have attached logs of 3 runs, Inputs and thoughts appreciated.


Attachment 21060

These 2 were back to back
Attachment 21061
Attachment 21062

Torque converters have the attribute that when they slip they multiply the torque going in (so the torque coming out is greater!) and they let the engine spin at a higher rpm (so that it runs closer to peak torque)... so basically at the dragstrip you can do better with the TC unlocked.

BTW: If you're tuning with two widebands, I can setup a pid to dynamically select the leanest bank (i.e. so your BEN correction will be for the leanest bank).



If you edited your calc_pids.txt post it here so I can add that.

Ok, on your next runs, I want to increase the scantool's frame rate (i.e. keep pid channel count to 24 or less) because I want to see in more detail some of the waveform changes...

so drop these pids:
- GM.FTC
- GM.TFMDC
- GM.IAC
- GM.TRQENG
- GM.TRQTRANS

Those are good logs, they show the TC couples nicely (i.e. while it is unlocked) and they show it locking solidly (as you said).


Attachment 21063
Attachment 21064
Attachment 21065