worthy upgrades for tamiya models are:
BEARINGS
alloy knuckles(the plastic WILL break on first decent impact)
decent tyres(stock are generally pretty soft and wear quickly)
ESC(dont go mechanical)
low turn motor(around 19t.)
assorted pinions and spurs(if poss)
alloy driveshafts
from there you can go things like heat sinks, deans plugs, 4000nimih batterys, lower turn motor, lower drag shells, the list is endless.. till its all done then you break it and start again
