3.4 on the M90.
3.2 on the 1320.
3.9 on the 1900.
Rated HP means nothing when you have the performance map which clearly states that if you were to push the blower any further than what I showed, you'd fall outside of the magical 70% AE.
Yet a 1900 would still be >70% for some time to come.
Based on the inefficient gen IV M90 and M112:
http://www.magnusonproducts.com/images/mp90g2.jpg
http://www.magnusonproducts.com/images/mp112g2.jpg
at 12 000 RPM and 10 PSI, 42 HP for the MP90 and 52 for the MP112.
You spin the M90 to 12 810 RPM, costs you 45 HP.
You spin the M112 to 10 500 RPM, costs you 43 HP.
Fun times.
Edit: Hell lets use your chart.
R1320 14 300 RPM for 1080 m^3/hr at a 1.8 PR.
R1900 10 500 RPM for 1080 m^3/hr at a 1.8 PR.
1320 uses 30 HP.
So does the 1900....
Hmm...
