Retired Air Force
How much if any can a change in nozzle insert size change max RPM?
going from a 3.0625 (teal) to a 3.125 (red), you won't see any difference in rpm. A+ is awfully big, especially if it's blueprinted. at what rpm does it make 850, and what is the rpm you are seeing with this impeller. at what rpm does peak torque occur???I had the teal (smallest) one in with a A+ impellor and 850hp. Too small maybe? I will try the red next time out
true, but the physics depends on the application. these are single stage axial flow centrifugal pumps. and generally speaking, because it's a single stage, accepted centrifugal pump laws don't apply. when the orifice size is changed, mass flow rate and velocity are altered. if one value increases, the other decreases. it's solely fine tuning.I thought that physics would say a restiction in orifice size would lead to an increase of pressure. To pump more pressure takes more power? My POS wouldn't keep up. I think I'd lose RPM. But what would it do to my foward progress and at what cost/Benifit?
Keep in mind the altitude corrected weather conditions. The air in my part of the country was killer good yesterday. My dyno was actually correcting down from the observed or measured power. Here the engine will make five to eight percent less power in the summer which will affect the cut on your impeller if you are trying to get it spot on with your power curve.Once I know the engine is running right I will send impellor back if needed.