Methods and systems for improving the operation of transmissions for motor vehicles

A method of modifying a factory installed automatic automotive transmission having a torque converter clutch solenoid controlled by a vehicle onboard computer for applying pressure to a first end of a torque converter clutch valve for moving said torque converter clutch valve in a first predetermined direction, a spring arranged for applying a resilient force to a second opposite end of the torque converter clutch valve to oppose said movement of the torque converter clutch valve in said first predetermined direction, a factory installed balance oil orifice arranged in the hydraulic circuitry for applying balance oil to said second end of said torque converter clutch valve for further opposing said movement of said torque converter clutch valve in said first predetermined direction, wherein the steps of said method include:

• providing a replacement balance oil orifice arranged to cooperate with said torque converter clutch valve, the size of said replacement balance oil orifice being different from the size of the factory installed balance oil orifice for controlling the pressure applied to the torque converter clutch valve to a maximum predetermined value greater than that of the automatic automotive factory installed transmission,
• said factory installed transmission further including a solenoid controlled by said vehicle onboard computer for applying pressure to a first end of a trim valve for moving said trim valve in a first predetermined direction, a factory installed return spring applying a resilient force to a second opposite end of the trim valve to oppose said movement of the trim valve in said first predetermined direction, a check ball seated in a seat for controlling balance oil pressure applied to said second end of said trim valve for further opposing said movement of said trim valve in said first predetermined direction, wherein the steps of said method further include:
• replacing said factory installed return spring with a different return spring having a spring characteristic which controls main pressure of the hydraulic circuit to not exceed a predetermined value less than the main pressure of the factory installed transmission for decreasing the time for completing an upshift to a predetermined range of time less than that of the automatic automotive factory installed transmission.