You have a wheel or a DS3?
The technique I used involved skipping 3rd gear and going straight to 4th, this kept my acceleration to a slow enough level so that I could make it through the cones, but quick enough to pass the test with a gold.
Another tip: don't mash the gas pedal until RIGHT BEFORE the start. you don't want to be sitting on the rev limiter when it starts. You want the car to take off at about 5000rpms, it'll take off with the least amount of wheelspin and the most amount of acceleration.
What time was it you got? I couldn't see it there.