The SR20VE CVT tranny or the P11 type auto?
The P11 type auto works well but you need to have the right ecu/programming combination to engage/disengage the lockup solenoid at the right times. Everything else is simple, its cable kickdown, pushbutton overdrive, PNP switch is a no brainer. An external oil cooler is recomended.
CVT tranny is a different beast, the torque rating is limited to about 160ft/lbs or Whatever the QR25 makes stock, a bit more than that. So not to exceed that torque rating, change fluids on time, don't run it with issues(sensors bad/slipping) as it stresses the belt and leads to failure. If its been sitting a log time in a scrapyard, especially without fluid, a service of the valvebody is recomended.
So to answer your question if it pertains to the CVT, make the engine more powerful and then change the programming of the TCM to utilise the increased power and/or extended rev range. large external cooler. Don't exceed the safe torque rating.
If it pertains to the regular tranny get a stageII or higher shift kit installed to suit your HP goals. Make the engine more powerfull, medium to large external cooler(depends on ambient really). Make sure your electronics support control of the lockup solenoid else you will be running with torque convertor slip all the time. Make sure the bushing for the nose of the convertor is still in the crank and its the right size for your torque convertor else bye bye flex plate. Also put some grease in it at assembly(convertor nose bushing), just a touch.