There is no such a thing as "turbocharger training" there is only type conversion training on an aircraft with turbocharged engines(s).
Not quite right under JAR. A pilot requires differences training on a number of areas this includes turbo chargers and this requires a log book endorsement. This does not even have to be done in an aircraft for turbocharging, it can be done as a ground school. Once the endorsement is in the log book then you have had 'turbocharger differences training'.