General transmission pressure questions

[jakeshoe]

OK,
I'm in learn mode.
What are the disadvantages of jacking up line pressure?
I know it adds clamping force to the clutches, but stress to seals, but what else.

What are the advantages/disadvantages of bigger boost valves. Basically exactly what is their function.
TV Boost
Reverse boost
etc..

I have a decent grasp of how the older 3 speeds work but am kinda lost on the newer TV type trans.

TIA

 

[chris718]

the largerdiameter of the boost valve the more pressure modulated tv oil exerts against the pr valve keeping it diwnshifted .and the more the valve is held downshifted the greater the pressure the pump pocket must build to open the valve .this pressure is then broken down into several other variable pressures some of which operate at much lower than the line pressure,much like checks and balances.www.ckperformance.com

 

[jakeshoe]

OK,
so TV pressure serves the same function as modulator pressure in a 3 speed.
That's easy to understand.
What does the line bias do?
Where can I get a good book on all this that goes in depth?
I can read it over and over till I have it memorized
I have the ATSG manuals but doesn't give the info I need.
I don't need anything specific to a particular trans just good general info.
I don't like to just make a modification I like to know WHY I am doing what i am doing and what exactly it does. I also like to know what the positive and negative effects are. Nothing's free right?

 

[chris718]

line pressure becomes 90 psi at the tv limit valve,and becomes a regulated 0 to 90 psi at the throttle valve (0 being closed throttle and 90 being wide open)this regulated pressure is tv oil which is modulated at the line bias valve to control punp pressure according to throttle angle and the rapid build up of torque in the lower rpm ranges.the line bias valve controls the amount of modulated tv oil sent to the boost valve .it is this pressure which flows to the clutches and bands to control clamping loads applied from the clutch pistons or servo against the steels and frictions. no book neccessary .you got a basis now to start modifying .there is a book called automatic transmission fundamentals out there but i found it boring not answering the deepest working of planetary ratio formulas and thrusting forces .www.ckperformance.com