well u don't give any detail on what car u have. Im assuming u have the Tamiya TL-01. Well, berings are a must. If u wana get the tamiya berings ive found them for 69 dollars at tower. kind of a lot of money. i think that the duratrax set is like $30 but not positive. The speed tuned gear set will also increase the speed. Almost everyone agrees that a ligh car goes faster than a heavier car, so get the light weight chassis and get the carbon shafts.
lol ...well on the rcca board, people are talking bout how their tl-01s are beating tc3's and the others.(in the tl-01 thread)I don't know what they are doing to their cars, but the tl01 has potential.