1: Make sure you have the best tires allowed
2: Make sure Bob is not orange before the race
3: won't hurt to lower the gearing a bit on the car to get more accel
4: Carefully direct him to the front. If he starts drifting and smoking the tires pace him down if he starts getting into the blue pace him up.
This one is a bit harder than the Indy race but with the right setup and the right instructions Bob will win it.