Originally Posted by
00GrcyGtr
I have come up with other questions on these trans. you have Force Motor Current, (an item I don't touch) Shift Scheduling, (which I mostly understand except question in my just previous post) Shift Pressures > General > Pressure Pattern (all set to pattern X) as you mentioned and then we get to Upshift > General and pressure modifiers.
My question is since you can modify pressure under General (Pattern X) and as well adjust pressures for 1>2, 2>3 shifts etc. I am just wondering if you should or not, and possibly which is better to adjust?
It seems the adjust under General > Pattern X would increase pressure across all tables, so why would you need to increase the pressures on the "per shift" tables as well?
Then we get to Shift Timing > Base, Adder and Multiplier, which is greatly confusing as I am to understand the idea is to "reduce the amount of torque" at the moment of shift to keep from slipping "feeling like it takes 30 seconds to shift" but yet making it crisp and quick, not so much harder (maybe just a tiny bit), but the factory tune in this thing had pressures and shift points that would hit pretty firm at 10mph under minimal throttle.
I have adjusted these items a bit as I read and learned more, the shifts feel great at lower rpms/speeds, no take off and bang into 2nd under normal driving, but I also know these 4L70's are a weak link in this heavy hot rod, so I have never had anyone or read anything that really spells all this out very well, other than one member said the tranny is happier when it is shifting (that 300ms) time or so at a lower torque (but more pressure), which I have increased the Torque Mngmnt > Torque Reduction a good bit from the factory setting, about 20 to 35% in fact or close. I have also increased both the General > Pattern X and the 1>2, 2>3 mofifiers.
With a higher mileage truck, even though I have a warranty (my best buddy is my shop guy) so no worries there, I don't wanna blow my tranny anytime soon for setting something in the tune very wrong.
So basically is raising the pressure in thegeneral pattern X really even necessary if you can increase the pressure modifiers only on the shift pressure modifiers?
Thanks for all the help by the way, much appreciated!