I believe he's talking about tuning the car, you know after you do upgrades such as exhaust, cam, ect ... I don't exactly know what they do to the T/A's but usually it has to do with changing factory settings on the computer using an OBII (ob2) scanner to optomize the performance of the car. Usually this is done by someone with a dyno or at a track to get the best performance out of the car. For an auto car they might be able to change the shift points, for all cars they can control the air fuel mixture (I think). Some of the drag racers could probably shed some more light on this subject.