4l60e desired shift times

[bhm99]

So im trying to figure out how i should tune my shift times. I have a 4l60e with a vette servo. I have my torque management reduced by 50 percent already. Could someone please tell me why the 3-4 shift times on the normal table are zeroed out. What should i set them to? Also why are the values for the performance table so high???

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[df2x4]

I'm no expert and this isn't what you asked, but personally I would not be removing torque management from a 4L60E.

EDIT - Or changing much of anything related to it in the tune, for that matter.

 

[L31MaxExpress]

3-4 shift times are zero'd in every tune I have run across. I set the command shift times for 1-2 and 2-3 to 0.300 seconds. I use 40% torque reduction flat across the 1-2 and 2-3 shift. I also use the Tow/Haul line pressure map out of something like a 2002 5.3 Tahoe tune. The result is a firmer shifting trans with less slippage and cooler running. I also make a change to the pressure control solenoid map. I zero the 90 "psi" and 100 "psi" lines.

If you zero out or reduce the torque management you will cause the trans to slip during shifts and eventually cook it. You want the trans to shift quicker and cutting more power during the shift helps accomplish this along with the higher line pressure and shorter commanded shift times. The torque reduction is only in effect for the length of time of the commanded shift time. Here is what a stock 4L60E with Sonnax Superhold 2nd and 4th gear servos shifts like with the settings above. The real sharp snap you hear during the shift is the out of the exhaust due to the engine running at Zero timing advance for the 0.300s of the upshift. The shifts were very quick and crisp and not soft, delayed and sluggish like the stock setup yet not overly firm either.

Performance mode is Tow/Haul and they cut more power when it is in Tow/Haul to help keep the trans alive under the abuse of towing. More power being cut equals less abuse, less clutch slippage and cooler trans temps. If you look their is also more torque reduction % in Performamce mode.

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[bhm99]

3-4 shift times are zero'd in every tune I have run across. I set the command shift times for 1-2 and 2-3 to 0.300 seconds. I use 40% torque reduction flat across the 1-2 and 2-3 shift. I also use the Tow/Haul line pressure map out of something like a 2002 5.3 Tahoe tune. The result is a firmer shifting trans with less slippage and cooler running. I also make a change to the pressure control solenoid map. I zero the 90 "psi" and 100 "psi" lines.

If you zero out or reduce the torque management you will cause the trans to slip during shifts and eventually cook it. You want the trans to shift quicker and cutting more power during the shift helps accomplish this along with the higher line pressure and shorter commanded shift times. The torque reduction is only in effect for the length of time of the commanded shift time. Here is what a stock 4L60E with Sonnax Superhold 2nd and 4th gear servos shifts like with the settings above. The real sharp snap you hear during the shift is the out of the exhaust due to the engine running at Zero timing advance for the 0.300s of the upshift. The shifts were very quick and crisp and not soft, delayed and sluggish like the stock setup yet not overly firm either.

Performance mode is Tow/Haul and they cut more power when it is in Tow/Haul to help keep the trans alive under the abuse of towing. More power being cut equals less abuse, less clutch slippage and cooler trans temps. If you look their is also more torque reduction % in Performamce mode.

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So basically you are saying dont mess with the 3-4 shift time on the normal table and dont mess with the tow haul mode torque reduction or shift times? Could you provide maybe a few photos of some tables i could look at or maybe even a hpt file? Im kinda new to this and i want to learn the best i can.

 

[Supercharged111]

I'll echo what Fast stated, 3-4 on both the 4L60 and 4L80 is always zeroed while the rest live in the .4 range. I've shortened mine beyond the .3 range with no ill effects. I think the right answer is to bump line pressure until the shortened shift times are met with minimal shift correction trims, but I haven't bothered to learn that far down the rabbit hole just yet. Definitely keep some torque reduction on the 4L60, I think I cut mine in half and left it but my 4L80s have no torque reduction because I don't feel that they need it. My 1500 with a shift kit will slingshot you good from a WOT 1-2, but at the same time it's not harsh at all. I need to get a shift kit in the dually at some point too.