Forget 2 minute turns. Those are for instrument procedures.
The turn you make (bank angle, radius) is going to vary depending on the met conditions, traffic conditions and terrain surrounding the airfield concerned.
The purpose of an orbit is to create a bit of space between you and the traffic you are following, without leaving the general area you were operating in. It is up to you to select a combination of speed, and bank angle that allows you to accomplish that spacing without losing your ability to spot other traffic and maintain your situational awareness.
2D