I have a 6A with an IO_320 and a Catto. Up at 8K, I get 190 MPH under 8 GPH. Due to weather, I have had to make several flights around 2500-3000 (DA around 4K or less). I routinely fly LOP, but have avoided doing so above 75%. I have done some research and now understand that I can go to 80%+ power if I can keep to 60* LOP.
At these lower altitudes, I can't seem to get much more than 2500 RPM, which gets me 175 MPH. If I go LOP (30-40* LOP) at 8 GPH, I should be netting 75% power and this gives me the 2500 / 175. I can't seem to find a way to get more RPMs without richening up. The only way that I can get higher RPMs / speed is to richen it up, which gives me more power, requiring that I go more LOP and can't seem to get there from here. I have tried adding more MAP via the throttle, but without more fuel, it doesn't net more RPM.
Is this just an aviation fact of life at lower altitudes? I could go 150-200 ROP, but don't want to throw that much gas at it for another 10-15 MPH.
I would appreciate some education in this area.
EDIT: I should add that my prop is just a bit under-pitched. I generally like this as it lets me turn more RPMs up high and give me a bit better climb. At 8K I can turn just a bit over 2800.
At these lower altitudes, I can't seem to get much more than 2500 RPM, which gets me 175 MPH. If I go LOP (30-40* LOP) at 8 GPH, I should be netting 75% power and this gives me the 2500 / 175. I can't seem to find a way to get more RPMs without richening up. The only way that I can get higher RPMs / speed is to richen it up, which gives me more power, requiring that I go more LOP and can't seem to get there from here. I have tried adding more MAP via the throttle, but without more fuel, it doesn't net more RPM.
Is this just an aviation fact of life at lower altitudes? I could go 150-200 ROP, but don't want to throw that much gas at it for another 10-15 MPH.
I would appreciate some education in this area.
EDIT: I should add that my prop is just a bit under-pitched. I generally like this as it lets me turn more RPMs up high and give me a bit better climb. At 8K I can turn just a bit over 2800.
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