Edit : Users EvilTrovis and Naaza both pointed out that the mission where you run Durar's Time Trial will not count fir this achievement.
This can be done once accepting the quest "Arming Your Buggy" from Sherriff Black in Wellspring. You will spend a bit of time talking to various people til you finally have to speak to Slim. Slim will show you what races you can participate in. Just select 1 of the 2 available and race. Time trial isn't all that difficult as long as you keep your buggy on the track and grab most of the boosts. Once the race is done the achievement should pop.