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I have a 4l60e with corvette servo. I'm looking at little firmer shifts and a little quicker. The only torque management i did was took 50% of torque reduction and set the whole desired shift time to 0.300. Is this the right way about going to doing this?
Retain the factory shift time tables, try reducing by a percentage across the board (like 10% at a time until it's shifting at the duration youd like)
For firmness, do the opposite to shift pressures, adjust pressure UP by about 5-10% at a time until you reach your desired firmness.
I've never changed the torque reduction, I know there is one table that says it's not recommended that you change it. It says that when you highlight the table with your mouse but I forget what table it is.
Otherwise you can change the shift pressure itself, add 5-10% should help. Just know that stock 4L60e are weak and don't take well to hard shifts/high shift pressure and abuse unless otherwise built for it.
how do i do theses tables by percentage?
Use the math function top right.
For example, 10% increase, highlight everything, type in 1.1 and hit X to multiply.
For 10% decrease, highlight everything, type in .9 and hit X to multiply.
For the base shift pressure table, I first change the 0 ft lb column of the 1-2, 2-3 & 3-4 shift table to 0. Then change the 640 ft lb column of the 1-2, 2-3 & 3-4 shift table to 40. Now highlight the whole table & click on the "Interpolate Between Horizontal Bounds"
button.
Now the shift table will be 0 at the 0 ft lb column & 40 at the 640 ft lb column. Now copy this table & click the "Undo All Changes" button. Then right click on the table, go to Paste Special > Add. This will add 0 psi at the 0 ft lb column of the shift pressure table & 40 psi at the 640 ft lb column. The editor should clamp the max pressure to 96 psi.
Also change the Max Pressure to 96, as it usually is 90 stock. If you what firmer shifts, use 50 psi at the 640 ft lb column and 30 psi for softer shifts.
I always leave the shift times stock on the 4L60E/4L70E.
What vehicle? On the trucks, I halve the upshift torque reduction. On a car, I zero the upshift torque reduction.
Russ Kemp
This will be fine on a transmission that has some miles on it and it's also a stock build trans just has corvette servo
I have a corvette servo and 4.56 gears. my 1-2 shift hits to hard and chirps the tires. I have factory shift times. Should I reduce shift pressure in autoshift properties->shift pressure-> Base X pttrn? and is there a minimum pressure for a 4l60e? Attachment 61044
Have you altered the tune for the corvette servo yet? After you have the correct calibration for the vette servo, start reducing shift pressues until your reach your desired sweet spotQuote:
Originally Posted by AJK13
I'm trying to alter the tune for the vette servo. I'm just not sure what tables to work in. I reduced 1-2 pressure hoping it wouldn't hit so hard. Are there specific tables I should be working in for the 1-2 servo?
is there a minimum shift pressure for 1-2 shifts across the torque range?
Hey AJK13, did you have any success with the 1-2 change, mine was so violent that it was like being re-ended every time , I got to fear it..... but reducing pressures on 1-2 a little and increasing the times to 0.75 sec in the lower half of the range made it a lot better.. Its only too harsh at very low rpm on 1-2 now , very low like just off idling in traffic... but I cant seem to get it any better even increasing the time to 2.0 seconds doesn't help, and even lowering the base pressure down to 45 psi at low throttle settings makes no difference..Attachment 63528
Depending on your gearing and stall, have you considered starting in 2nd for low TPS situations? I've done that before on built 4L60s with success because of the mechanical changes to th valve body and resultant 1-2 shift regardless of TCM settings. This is not really an option if you're very heavy or large stall, but worth considering in some cases.
Hi SS, I used to have it set up so it went into second very quickly (kind of what you meant I guess) and its noticeably softer but got sick of wasting first gear... Its not too bad now but I would soften it a bit if I could.. So are you saying that a built transmission is not very responsive to some changes using HP tuners ? I'm thinking you must be correct. I keep reading that you should always tune it to suit the corvette servo, but cant find an explanation of what that tune is.... assuming it can only be 1-2 time and pressures but and maybe default pressure x TPS, but no-one seems to specify what exactly... thanks for input.
I did about 50% TQ reduction during 1-2 shifts. it helped
I added 10% to the shift pressure table and took away 10% from the desired shift times until some numbers where under 0.3, then added 5% to the parts where it was under 0.3 sec until they where there and the car shifts like a modern dsg vw on light throttle , stock 4l60 on a camaro with the ca,aro servo
Russ K that is good info. Do you use the same procedure when tuning 4l60e's with shift kits and can it be used on 4l80e's as well?
Yes and yes.Quote:
Originally Posted by hodge9386
Russ Kemp
I have some questions any chance you can Message me [email protected]Quote:
Originally Posted by Russ K