Difficult to say as I haven't raced mine yet!! From reading reports from people who have raced them in the past, it would seem that they are pretty competitive.
Shocks are the first thing to change, I have 3Racing ali ones on mine. I have also fitted Team Atlas steel diff halves, GPM ali steering parts, GB02 front end, GB02 soft compound tyres,Tamiya side bumpers and I have a milled motor plate, ali rear hubs, steel cvds, heavy duty hinge pins and steel pinions all on the way. I have a Team Orion brushless system with the 6000kv motor witha 1600 lipo and will probably fit the Futaba S3102 servo at some point in the near future.
This all sounds alot but in reality I think the shocks and battery with a faster brushed motor will see you pretty much on the pace. Hope this helps a bit.
