4l80E ancient history

[phantom309]

Does anyone remember where/ how to put a resistor in the line to the electronic pressure control solenoid,. so as to give more line pressure?
There was a write up way back about adding a resistor,. just the right size gave the best results etc,.
Thanks Nick

[DennisG01]

Nick, I'm not sure if this is what you're referring to, but Heath has a write-up on how to give manual, lock-up control.

http://heathdiesel.com/manual-operation-of-the-torque-converter-lock-up-clutch-in-1992-1995-trucks-with-the-4l80e/

[phantom309]

Nick, I'm not sure if this is what you're referring to, but Heath has a write-up on how to give manual, lock-up control.

http://heathdiesel.com/manual-operation-of-the-torque-converter-lock-up-clutch-in-1992-1995-trucks-with-the-4l80e/

Thanks Dennis , thats not what i was looking for, although thats a very good mod that i like to do, just remember not to use cruise control with it on manual lock,.;)
B+M put out an electrical shift improver,. it basically fools the electronic pressure control to raise line pressure at a better ratio to tps input, giving firmer shifts and better holding power when pulling,. it,s basically a 2 resistor setup,.
So i ordered a resistor with a resistance right in the middle of the two B+M values, and we'll see how it works,. (10w 15ohm)
The bigger pump i have takes less tps input to achieve torque levels that need higher trans pressure,shifts are too early, too slow/soft etc, ,..so i need to raise trans pressure. I realise that A: a B+M mechanical shift improver kit would be the best choice, where pump pressure is raised with different spring and valve etc,.B: would be a reprogrammed chip,. but both those choices are either time consuming and costly,. or just costly,. so a 2.49c resistor soldered in the the epc circuit will do just fine,.I,ve been learning about this stuff since i posted this question,.
Thanks dennis.

Nick

[phantom309]

So i spent some time and researched the electronic pressure control EPC on the 4l80e.s and it is controlled by the ecm,.
B+M put out an electronic shift kit a few years back (still available) which basically tricks the epc to raise trans line pressure making the shifts firmer/quicker, and better apply pressures etc,. etc,.
B+M,s 'kit' was a switch that had 3 positions
1 was factory settings,.
2 was firm
3 was firm-er,.
They did this by adding resistors into the EPC circuit
position 1 resistor was 7ohms, position 2 resistor was 22 ohms,
So i bought some resistors pretty beefy ones as i didn't want any issues with heat in the back of the dash,.
I bought 3 X 5ohm and 1 12ohm, all rated at 15W.
i figured i could build the combination i wanted from these 4,
The first one i chose to do was 12+5= 17oms at 30W,.
http://i39.photobucket.com/albums/e157/wtfuashols123/4l80e%20resistor%20upgrade/MVC-045S.jpg?t=1332035924
It,s perfect for me,. shifts nicely, much firmer, but not harsh.
so i,m leaving as is,.
i soldered the resistors together and taped them up,.and soldered them onto the correct wires (red w/blkstripe)(light blue w/white stripe)
http://i39.photobucket.com/albums/e157/wtfuashols123/4l80e%20resistor%20upgrade/MVC-046S.jpg?t=1332035924
http://i39.photobucket.com/albums/e157/wtfuashols123/4l80e%20resistor%20upgrade/MVC-047S.jpg?t=1332035923
put it all back
http://i39.photobucket.com/albums/e157/wtfuashols123/4l80e%20resistor%20upgrade/MVC-048S.jpg?t=1332035925

I,m pleased with what i accomplished,
Now i,m trying to research changing the 1 side of the drac vss box jumpers to try and fool the trans to shift later, without changing the speedo reading.
As i mentioned before, the bigger 5068 pump adds fule at a rate that doesn't reflect well thru tps reading for the trans, in other words very little tps movement and i,ve got power but the trans thinks it should shift too soon as in light throttle settings,.WOT shifts are fine. (better again now)
cost me 3.25 ea for the resistors,.a great mod for a cheap price,.

Nick