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Is dynon accurate

tracy

Well Known Member
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I didn’t think an o360 could make 75% power above 8k. I do have one electronic ignition. 0A37CD21-306E-495D-BAC3-DB66677DDF68.jpeg
 
Density alt over 11K? I agree, something’s not right. Usually these power readings come off a user-inputted data chart. Might want to check it.
 
The %Power read out is a model of the engine, and my not reflect actual engine power. There is also a step where you need to tell the EMS what engine you have.

Here you have a high fuel flow for that altitude, coupled with a high RPM. At 11K WOT I’m at 20.6” MP so your 20.8” sounds about right.

The result is you may be fooling the algorithm to show a little higher % PWR. Doing a quick look at screen shots, at 11000’ my SkyView is showing 63% power, and 68% at 9000’ (WOT, LOP).

Depending on your engine, you might want to try a leaner mixture at that altitude. This may be a problem with a carb, but worth a try. For my RV-8 I’d be around 8gph at that speed and altitude.

Carl
 
Ok, this is what the tach parameters are set to. I can see now that they are high. I guess the top three numbers should be set to 2700 since that is red line for o360. Also, the “engine horsepower” number is really an adjustment number factor. Instead of putting 180, I should be putting a higher number in to influence the percent power. It’s been suggested that the electronic ignition plus the faster rv speeds,ram air, the strait pipes all increase the power to around 195. Rpm and engine power are the two values that really effect % of power.
 

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If memory serves, this is just to set the red/yellow/green arcs on the display. It does not influence %PWR readout. This is the engine and engine rated HP input.

Carl
 
Changing the top numbers is a matter of style: do you want a wide red band, or a thin red line?
A real Hobbs meter is a clock that runs whenever there’s oil pressure. Your ‘normal cruise’ number is more like a tach hour setting. Since EAB maintenance is totally up to you, you can do what you like.
None of these will effect the calculation of % power. They must be somewhere else.
 
I thought they also differed for lean of peak vs not in how they compute % power.

Rich of peak they use some (manufacturer?) curves.

If you are lean of peak % power is basically proportional to fuelflow and 9 gal/h is 75%.

So if the Dynon is confused about if you are lean of peak or not that output makes sense even though its not true ... .

Oliver
 
Ups... . I just notice on the picture it says ROP so the LOP explanation above can't be true ... .

Oliver
 
I think if I just up the horsepower to say 195 in the setup mode, this will give me more accurate % power. This is according to an old post I found from dynon. When lycoming o360 was entered, it automatically puts 180 hp but these engines put out more due to speeds of the rv, ram air, and electronic ignitions.
 
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It’s been suggested that the electronic ignition plus the faster rv speeds,ram air, the strait pipes all increase the power to around 195.

I'm no expert, but I'm thinking that would be a pretty impressive gain...?
 
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