I would strongly suggest using dual-rate steering until your skill improves. If you limit your steering inputs you will find that you can control the angle and speed of the drift with throttle. Then as you get better, ease yourself into using full steering again.

There are a number of problems with drifitng a rwd rc car. Things like weight distribution are high on the list (its like drifting a 911 or an NSX), but another huge issue is the fact that you are getting full steering lock with a very small input to the controller. Can you imagine if your real car was like that? if you turned the steering wheel 45 degrees and got full lock? You wouldn't be able to drift a real car that way either. SO use a dual-rate controller and set the dual rate very high, and then go practice practice practice