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=5876
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....shift-firmness
http://forum.efilive.com/showthread....during-upshift


Regards,
Taz

[joecar]

Hi blsnelling,

Welcome to the forum

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]

Hi blsnelling,

Welcome to the forum

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. My Modified_02.tun

[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. My Modified_02.tun

Try the attached file.

[blsnelling]

Try the attached file.

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

[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?

[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]

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