These curcuit paths for the hydraulic fluid control how, when, under what load, throttle position, direction and speed the transmission shifts gears. Downshifts and upshifts. Modification of these ports, channel diameters, direction and cross dimensional size can effect all things. You can make later shifts, earlier shifts, mid throttle upshifts, firm shifts. The world is your oyster but you better know what you are doing
