Engine %HP calculation

[GalinHdz]

Where does SkyView get the engine %HP value? Is it based on the HP we enter in the setup, the RPM's, Manifold Pressure, is it a SAWG or some other calculation method?

:-?

 

[dynonsupport]

Those, and an internal table for specific engines.

Where does SkyView get the engine %HP value? Is it based on the HP we enter in the setup, the RPM's, Manifold Pressure, is it a SAWG or some other calculation method?

:-?

 

[GalinHdz]

So if we "adjust" the HP value we enter (to get the ROP/LOP to display properly) it changes the engine %HP shown?

:-?

 

[dynonsupport]

We have a really detailed description of % power here:

http://preflight.dynonavionics.com/2014/02/did-you-know-percent-power-dynon-way.html

As it says there:

One interesting thing to understand about percent power is that because it is a percent of the max rated HP of the engine, not an absolute horsepower number, the horsepower rating of the engine doesn’t matter.

So no, adjusting HP doesn't change the % power calculation at all. You cannot adjust the % power number displayed in any way- if it's off, your MAP, RPM, Altitude, OAT, or FF is off.

Now, the above is true if you are ROP (rich of peak). If you are lean, then it does make a difference, and the HP number is used for the LOP/ROP determination as well. Some more info on that here:

http://dynonavionics.com/cgi-bin/yabb2/YaBB.pl?num=1409279759/4#4

What engine are you flying, and what issues are you having?

 

[GalinHdz]

I have a Lycoming O360-A4M but the engineer in me is curious how the %power is calculated. I will have to read the additional information in the link.

So when operating ROP the %HP is an "actual" percentage and has nothing to do with the HP number displayed. Good to know.

:-?