Tuning a 4L60E with Transgo HD Shift Kit

[blsnelling]

I'm looking for advise on tuning the trans in my truck. I just put a 6.0 in front of it, hoping for 400 RWHP. I've had a Transgo HD shift kit in it for some time with aluminum accumulator pistons, and 4th gear hold servo. I had a 'vette 2-4 servo in it before, but didn't like the harsh 1-2 shift. That was before the stall converter. Probably wouldn't be an issue with my PT3200.

I currently have all shift times set to 0.00. I understand that's what I want since I have the shift kit in it.

What about Trans Pressures? I currently have all stock Performance pressures in the Base Pressure Shift tables, for both Normal and Performance columns. All other pressure tables are stock.

Of particular concern, I'm getting an occasional 2-3 flare at part throttle. I never had this happen before the new converter, engine, and tune. Any ideas there?

[Taz]

Try reading through the threads below ... I used the transmission tuning tutorial by Joecar when I was trying to learn "how things worked" ... it's a good read.

http://forum.efilive.com/showthread.php?t=1723 (http://forum.efilive.com/showthread.php?t=1723)
http://forum.efilive.com/showthread.php?t=5876 (http://forum.efilive.com/showthread.php?t=5876)
http://forum.efilive.com/showthread.php?t=10773 (http://forum.efilive.com/showthread.php?t=10773)

There are more tutorials in the "General information" portion of the Forum under the "Tutorials" category. Joecar has been busy sourcing applicable threads, and grouping these in a logical manner.

Couple of more threads regarding trans mods and the TransGo HD2 kit ...

http://forum.efilive.com/showthread.php?14020-Built-4l60-w-Transgo-shift-firmness
http://forum.efilive.com/showthread.php?14493-D2801-TCC-lock-during-upshift


Regards,
Taz

[joecar]

Hi blsnelling,

Welcome to the forum :cheers:

If your PT 2->3 shift flares, then see if this makes any difference:
- increase the 2->3 pressure table;
- set the 2->3 shift time table to 0.2 seconds all across (yes, this is counter-intuitive :) );

Post your .tun file.

[blsnelling]

Thanks Taz.

[blsnelling]

I think I narrowed this occurance down. If left in D, it shifts properly. If I start off with it pulled down in 1st, to keep it from shifting as I feather the thottle to prevent too much wheel spin, and then move it to 3rd, the 1-2 is great, but 2-3 flares BADLY. I hit 6700 RPMs before I let off. I then made two more runs with it in D, and it shifted correctly from 2-3 both times, no flare at all. What would cause that?

This has probably existed before now, but I've never had a problem with wheel spin, so never had to pull it into 1st to keep it from shifting as I feathered the throttle:rockon:

[blsnelling]

Hi blsnelling,

Welcome to the forum :cheers:

If your PT 2->3 shift flares, then see if this makes any difference:
- increase the 2->3 pressure table;
- set the 2->3 shift time table to 0.2 seconds all across (yes, this is counter-intuitive :) );

Post your .tun file.

I did bump the 2-3 pressures +6. My shift times are all at 0.0. You're saying to up them to 0.2? Yes, that's counter-intuitive:) How would that work? The above post may change your response though.

Here's ,my tun file. 9131

[Taz]

Hello blsnelling,

Took a quick look at your trans tune – with an eye toward the 2>3 shift issue you described.


Couple things became evident:

Performance tables have been copied over in Normal tables – values are the same in both
all desired shift times have been set to zero

To assist with the 2>3 shift issue, try:

D1102 (Low Pressure Adjust 2-3 Shift) – set all cells to zero (like the 3-4 shift)


D0702 (Base Pressure 2-3 Shift)

currently doesn’t reach maximum line pressure (96 PSI) until delivered engine torque reaches 458 Ft-lbs
becomes a case of “too little too late”
I prefer maximum pressure (96 PSI) to be reached in this table by 295 – 310 Ft-lbs


D0802 (Torque Reduction 2-3 Shift)

currently set around 8% - 10%
OEM LQ9 4L60E values top out at 38%
would set these in the 15% - 20% range until the 2>3 shift issue is resolved – then decrease as appropriate – currently putting a lot of stress on that clutch pack

Regards,
Taz

[joecar]

I did bump the 2-3 pressures +6. My shift times are all at 0.0. You're saying to up them to 0.2? Yes, that's counter-intuitive:) How would that work? The above post may change your response though.

Here's ,my tun file. 9131Try the attached file.

[blsnelling]

Thanks for the tips Taz. I had not yet noticed D1102. I've been playing with a lot of trans tables, but that wasn't one of them. That might really help. I also like your idea on D0702. Probably very wise advise on D0802 as well. Wasn't sure where to put torque reduction. Do you see a problem with Performance pressures in the Normal tab? I'm wanting to leave the Performance mode for what little towing I do, so made the Normal like some might the Performance mode.

[blsnelling]

Try the attached file.

Thanks. I'll check that out when I get back to my laptop later this evening.

[Taz]

Not a problem to have the Performance and Normal patterns the same - just serves to mimimize the dual shift patterns afforded by the Tow / Haul switch. I generally set the normal pattern to be firm, with near OEM PT upshift / downshift points. Then set performance (Tow / Haul) to be very firm, with increased PT shift speeds - for spirited driving / improved towing - depending on the application.

Nice project you have on the go ... great work so far ... read WeathermanShawn's praise in the other thread !!

Regards,
Taz

[blsnelling]

Try the attached file.

What's your logic behind making the 3-2 and 4-3 Throttle Kickdowns 100% across the board? Also, how can a slower shift time of 0.2 help the 2-3 shift?

[blsnelling]

Here's what I've got now.

9137

[joecar]

What's your logic behind making the 3-2 and 4-3 Throttle Kickdowns 100% across the board? Also, how can a slower shift time of 0.2 help the 2-3 shift?The throttle kickdown tables can interfere with the PT up/down shift tables... by setting them to 100% allows PT shifts to be controlled by the PT shift tables only rather than switching between PT shift tables and throttle kickdown tables.

The hydraulic hardware may be taking its time perhaps (for some reason or other); when the PCM has to meet 0.2 s it will successively increase the pressure rate until the time is met; try it to see if it makes any difference.

[blsnelling]

Gotcha. Thanks for the explanation. I'll set them all to 100% to see if the condition goes away. If so, I'll put them back like they are. Thanks a lot for all the help!

[Taz]

I leave mine at 100% ... FYI.

Regards,
Taz

[blsnelling]

That sounds very un-user friendly if you have to go WOT to kickdown a gear. Or am I missing something here?

[Taz]

PT upshifts / downshifts are controlled by RPM & vehicle speed - these are in the "Shift at VSS" and "Shift at RPM" folders. You definitely want a downshift at WOT (100%) - when you put your foot to the floor. If you've ever driven a 1980's version 700R4 transmission - you know how annoying an unwanted downshift is prior to WOT.

Keeping the WOT at 100% lets you tune the PT tables to suit your driving style - and will still allow cruising at high % TP. It also avoids potential conflicts between your Throttle Kickdown and Shift at VSS / RPM tables.

Regards,
Taz

[joecar]

The PT downshift tables have MPH on the vertical axis and TP on the horizontal;
any time the operating point (TP, MPH) crosses to below the curve the PCM commands the downshift;
so at some MPH if you increase TP, the operating point moves to the right and crosses to below the curve and you get the downshift.

All the F-car and Y-car calibrations came with throttle kickdown set to 100%.
Trucks tend to have some various curves for those tables.

The throttle kickdown tables are supposed to take precedence apparently, but I've seen a few cases where downshifts weren't happening or were delayed.

See this: showthread.php?3336-No-Kickdown (http://forum.efilive.com/showthread.php?3336-No-Kickdown)

[blsnelling]

Excellent info guys. Looks like I'll be leaving it at 100%:)

[nevinsb]

http://forum.efilive.com/showthread.php?14269-a4-4l60e-how-to-tune-with-new-3600-stall
http://forum.efilive.com/showthread.php?12902-4L60E-Yank-3600-Stall-3.42-gears-TCC-Apply-Release/page2

These are some of the threads that really helped me.

[blsnelling]

I'm wondering if I figured out what happened with that big flare I mentioned yesterday. I started off with the gear selector in 1st, then moved it up to 3rd after it shifted to 2nd. I'm wondering if the TCC locked at the same time it shifted into 3rd, and it was the TCC that slipped? I do know that it goes into lockup earlier in 4rd, than when I have it in D, and I've only experienced this when I didn't start with, and leave it in D.

[Taz]

Have you applied the previous discussed changes to transmission pressure, shift times, and torque reduction ? If so, have these made any noticeable change to the 2>3 shift quality ?


Regards,
Taz

[blsnelling]

Yes, I have. I just made several WOT 2-3 shifts, and there's not a hint of flare. Two of these I actually started off with it pulled down in first gear, which seemed to be a trigger before. I'm really thinking it was the TCC applying when it went into 3rd, which I now have eliminated. If I need lockup in 3rd, I can always bump it to tow/haul mode.

[Taz]

Nice to hear its working better. As you can tell, I'm a results oriented person - had to ask you how it worked out ! Once you're happy with the shift quality, and it shifts consistently, then you can revisit reducing the TR for that shift - had suggested increasing it to save the clutch pack until you sorted out the shift.

Regards,
Taz

[blsnelling]

Really strange thing happened tonight. Took off with the truck shifting normally. Then I lost OD. Came to a stop, and the truck took off in 2nd, unless I pulled it down into 1st. Still no 4th. I turned the truck off, pulled out the key, restarted it, and all was fine. What in the world could cause something like that? I didn't even make any trans changes today. I had just flashed a Desired Airflow change. Is it possible for something to get corrupted in the flash? I just flashed it again with a few changes. Hopefully I won't see this again.

[Taz]

Out of town currently ... no access to manuals ... sounds like the trans went into "limp" mode - can't remember on the 4L60E if you only have 2nd and reverse in limp ... also sounds like it was an intermitent problem - often the most difficult to diagnose.

Regards,
Taz

[blsnelling]

I wondered if it wasn't some kind of limp mode. I had 2nd and 3rd gears. Could too firm of a shift trigger that? The 2-3 shift is actually too firm now at part throttle, probably due to moving the pressure curve up when trying to fix my flare. I've dialed that back down on this last flash tonight.

[nevinsb]

Does it make a big clunk if you go from D - R - D?

[blsnelling]

Everything's normal now, and was as soon as I pulled the key and restarted it.

[Taz]

Scan to see if a DTC was set ... some DTCs don't light up the MIL.


Regards,
Taz

[blsnelling]

Would those have been cleared when I re-flashed the ECM this evening? BTW, a little Googling confirmed that limp mode on the 60E is 2nd and 3rd.

[blsnelling]

I think I figured out what caused my trans to go into limp mode on Wednesday. It did it again this morning. It was on the same road, first time on it since Wednesday. This road has multiple 90° turns, so lots of slowing down and down shifting. This time I checked the codes and it was something to do with the 2nd gear solenoid. It's on my laptop, so don't recall the exact code. I got to looking at my upshift and downshift tables, on on the 2-3 and 3-2 tables, the downshift table speeds where higher than the upshift, opposite of what it should be. The trans didn't know what to do.

[joecar]

Which DTC...?

Did you fix the upsidedown tables...?

[blsnelling]

I left my laptop at my parents:( I'll get back to you with the DTC. Yes, I've fixed the tables, but haven't really tested it out yet.