Try regearing the car a bit to work more power to the lower gears (faster accel), this will keep the wheels spinning longer.
Try not to rely on the handbrake, use it more for situations where you might be overspeeding and need to slide earlier than usual, or if you're understearing into a corner you can use the handbrake to get the rear out.
What tire pressures are you using? The harder your tires, the easier it is to slide the car, but they also heat up faster.
Try using a locked differential. This puts equal amounts of power to both drive wheels and is usually easier to keep them spinning as you wont have one tire catch grip and slow your drift.
It would help if you could post a replay of your attempts though, that way someone can look at it and suggest a different method of drifting that particular corner. As is, I'm not sure which corner you're talking about. There's many smaller corners that you can drift with the XRG just fine, and the longer ones where you might get half way around the corner before regaining all grip.
Hope that helped a bit