What could cause these differences in torque, power and BSFC?

Ive been doing some engine testing at university and have created some torque, power ad BSFC curves. The engine used is a JCB 4.4l twin turbo diesel engine. I then compared to my results to the manufacturers graphs and got these. I need some ideas on what could cause the difference in torque, BSFC? What could cause the peak torque to be higher and the torque band narrower and the BSFC to be higher? I believe that the engine used in the uni test cell is a development version of the dieselmax and the one in the manufacturer specifications was the production model what could they have changed to cause the difference. Also the engine in the test cell is relatively green (not run in very much) which would surely mean the torque and BSFC would be lower which is contrary to the results. Maybe there is some calibration errors in the equipment? Some ideas that i could look into would be great if you have any. Thanks :)



Heres the graphs

http://ift.tt/1dEWzTC