May i ellaborate a little please Mike?

Air injectors are also required for such trim levels that require us to run less boost at certain RPM and load points to prevent a phenomenon known as "Surge".

In these instances we can keep the compressor below its surge line until such time as we can increase the boost in keeping with the engines consumption capability.

Air injectors are also very usefull for programmed peak boost levels with smaller turbos where we want the peak to occur only within a pre determined RPM area. This is not possible with Amal Control.

Hope this helps.