What the TC does is when you are on a slippery road or something of the sort and the back tires start to spin, the TC kicks in and it reduces the power going to the rear wheels. The engine will start to skip for a second or two and then once the rear tires have traction again the system goes back to normal. When you race your car you have to turn it off if you are going to heat your tires up and you will also lose a lot of time on your launch if it is turned on. Sometime when you are on a wet road or dry road for that matter, get down on the car real hard on good time. You will know when the TC comes on because the power of the car will die and the little green wheel spinning will come on in the dashboard. Hope this helps! 
