i got mine threw winning races and being noticable. try going to diffrent tracks talk to people and make your bike stand out. try visiting the local shops asking them about sponsorship.
i dont know how fast i got it up to but on the track i can beat 400's and some 450's.
my sponsors are oas race team, burnoutbarn.com, and advantage trailers you can check out my site at http://gandgfamilyracing.com its still under custruction going to get some more pics soon.
they give you discounts on parts and sometimes give you free parts in the long run. like my bars for instance they retail for $70 i got them for $30 and a pants and jersey $20 bucks with name and number and pants $30. and no i have nothing done to the motor I'm planning on getting a 450 soon.