[OFFICIAL] Manual v. Automatic Thread

[Crash]

Yeah. I know about all that. But in the end, you're not really tuning the trans. Tuning a motor doesn't make the block handle more horsepower.

Changing the springs to stronger stiffer springs in the AT also helps it handle more power. Adding planets to the planet carrier, putting in a bigger ring gear, and putting better clutch packs in ALSO make the trans stronger. But that's not tuning. That's upgrading. Increasing line pressure to the valve body doesn't necessarily increase the transmissions strength, but it does help get quicker shifts. A shift kit will generally do this. A good shift kit will usually come with upgraded springs to handle the increased stress.