Shift kits are a bit different. A shift kit makes it shift harder/at higher RPMs/Lower rpms, however you want to set it. If it is taking a few seconds for your car to launch, thats a lack of fluid getting to the clutches, Not good. A torque convertor with a stall allows you to keep the RPMs up and then climb right out at high RPMs. For example, you keep the motor @4500 rpms at the yellow, you only have to climb 1000 RPMs and you launch like mad. After that, the fluid has been flung around the converter and it acts human again.