What did they charge you with? In WA, racing is considered reckless driving. After doing some research I found:
RCW 46.61.530
Racing of vehicles on highways — Reckless driving — Exception.
No person or persons may race any motor vehicle or motor vehicles upon any public highway of this state. Any person or persons who wilfully
compare or contest relative speeds by operation of one or more motor vehicles shall be guilty of racing,
which shall constitute reckless driving under RCW 46.61.500, whether or not such speed is in excess of the maximum speed prescribed by law: PROVIDED HOWEVER, That any comparison or contest of the accuracy with which motor vehicles may be operated in terms of relative speeds not in excess of the posted maximum speed does not constitute racing.
http://apps.leg.wa.gov/RCW/default.aspx?cite=46.61.530
The prosecutor will have to prove that you were racing in a "reckless" manner. As noted above, speeding up not does necessary mean racing. I also agree with that you don't need a lawyer. I'm not sure if WA judges are very liberal. Just don't make him/her not like you - be honest. GL