I would say get some track time!! You don't even know if you need to make it faster (or need a 450 for that matter) if you haven't ever rode on a track yet. It may run faster than what your ready for now. Then go from there. You'll learn alot after a few times on a track. (practice perferably) If you bottom out alot, look into some shocks. If its tippy in the corners, widen it out. If you just don't have enough power, I would say look into a 450 before adding alot of go fast parts on the 400. Just my opinion though.

 

I ordered my T-4 Exhaust and boots today, I am down to the tether switch and nerfs and I am ready!