I am doing a science experiment dealing with car physics. The experiment I am doing involves battery-powered toy cars approximately the size of a hand (four-wheel drive). I am not sure what effect the weight distribution has on the acceleration of the car. To be more specific, I am looking for the effect of weight/downforce applied to either the front or the back on weight transfer/traction. I am attaching weight to the front for one kind of a car(Car F) and the back for another(Car B) and testing the time of the two in a straight-line race. According to my data, the car with the weight attached to the back(Car B) is faster. The only explanation I can come up is that the time which it takes for the weight transfer to take place for the car with weight attached to the back(Car B) is less than the other car(Car F), which makes Car B to accelerate faster. Would you explain why the difference took place? Also, I am not sure if the traction caused by downforce in the front or the back has any different effect on the speed.