Doesnt seem a bad compressor at all, it will flow 3 - 450 bhp at up to 2bar of boost without dropping too poorly in efficiency and stays quite well out of the surge area when doing so. I would say its a turbine trim issue personally, but the maps there are not necessarily correct as the names change when you enlarge them so its hard to say, but its certainly a large trim for a GT28 Turbine.
Originally Posted by Jamz
Seems it's also known has a GT25/40....
It cant be. The naming convention wont allow it.