Without a pitch change on the prop to eat up the extra power you won't get any faster without exceeding RPM limits. Sure, you will run lower throttle settings at cruise RPM, therefore better fuel burn. You should also get better climb at lower IAS because the extra power can be consumed as opposed to just increasing RPM.
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Power Flow Exhaust and O-320 PIREP
- Thread starter AKBill
- Start date
Not looking for absolute numbers but rather relative numbers, ie does Power Flow make a difference and how much percentage-wise.A tethered prop is going to be operating in dirty air. Not sure that would tell you what you want to know. You’re also not going to want to run the engine at full power on the ground. Will suck in crap and overheat the engine.
Also, you wouldn't need to run it for very long. Automotive dynamometers seem to take only a couple seconds to get a full graph.
Well said, sums it up, at least my experience in our 172. . .Without a pitch change on the prop to eat up the extra power you won't get any faster without exceeding RPM limits. Sure, you will run lower throttle settings at cruise RPM, therefore better fuel burn. You should also get better climb at lower IAS because the extra power can be consumed as opposed to just increasing RPM.
Hawaii_Bruce
Filing Flight Plan
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- Aug 15, 2016
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Bruce
With no change in prop pitch, you can't go faster regardless of horsepower.
I went from 53" to 63" prop pitch and at 2550 rpm I now go faster because I have more horsepower and pitch.
If one only increased the pitch with no change in horsepower, you wouldn't be in the TCDS static rpm limits.
According to Sensenich every pitch increase of 1" will cause a 35-40 rpm drop in static rpm with the same horsepower.
With increased horsepower to overcome the 35-40 rpm drop, they say you gain about 2 mph.
My static rpm is 2250+ or so depending on weather conditions (density altitude) with the 63" pitch. 10" pitch increase at 2550 rpm comes out to +23 mph in forward track, less slip.
I'm happy that I can do 130 knots on the glideslope and stay below 2600 rpm, without buying a 182 that burns way more fuel.
I went from 53" to 63" prop pitch and at 2550 rpm I now go faster because I have more horsepower and pitch.
If one only increased the pitch with no change in horsepower, you wouldn't be in the TCDS static rpm limits.
According to Sensenich every pitch increase of 1" will cause a 35-40 rpm drop in static rpm with the same horsepower.
With increased horsepower to overcome the 35-40 rpm drop, they say you gain about 2 mph.
My static rpm is 2250+ or so depending on weather conditions (density altitude) with the 63" pitch. 10" pitch increase at 2550 rpm comes out to +23 mph in forward track, less slip.
I'm happy that I can do 130 knots on the glideslope and stay below 2600 rpm, without buying a 182 that burns way more fuel.