For this achievement you must earn the Platinum medal in the Bobsleigh challenge, which is the DC Challenge in the 3rd season during the Winter X-Games.
Make sure to break before you turn, not as you turn.
After the first hairpin, try keeping the accelerator down all the way to the bottom of the hill.
Only use your E-Brake once, during the tight hairpin mid-way through the track.
Try following the racing line in the video below.
Here is a video on how to complete it with a fast time and including tips and tricks: