K factor for Red Cube

Battson

Bearhawk
Joined
Aug 16, 2012
Messages
134
Hi - our fuel transducer seems to be reading about 12.5% too high, that is we show more fuel flow than we expect to see based on the expected values for our engine, but we aren't 100% sure whether it's the transducer or if we're just running super rich, somehow... We've yet to analyse our actual consumption vs calculation.

I want to adjust the K factor, from 68,000 up to 76,500, but first I want to to confirm that such a large adjustment is "normal" when tuning a Red Cube transducer. I would have though it would be a known k value and 12.5% error seems like a lot to tune out - so I am hesitating.
 

dynonsupport

Dynon Technical Support
Staff member
Joined
Mar 23, 2005
Messages
13,226
Adjusting it that far is not normal at all. It should be within 3%.

The only real way to calibrate the sender is to actually check your fuel burn against what is reported.
 

Battson

Bearhawk
Joined
Aug 16, 2012
Messages
134
Thanks, I suspected that might be the case. So something else is out of whack... I shall investigate.
 

ricardo_godoy

I love flying!
Joined
Apr 24, 2013
Messages
46
to get a correct reading, I had to reduce the K factor for 42000 because he was giving information below real, my maxima gl / h is 26, and was presenting a reading of 17 gl / h. Continental IO 550 B
 

dynonsupport

Dynon Technical Support
Staff member
Joined
Mar 23, 2005
Messages
13,226
That sounds like you are using the Floscan (silver) sender, not the EI red cube.
 

ricardo_godoy

I love flying!
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Apr 24, 2013
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jake...atacched drawing, I'm away from my base, 540 kilometers, so I can not take a picture.
 

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jakej

Well-Known Member
Joined
Oct 10, 2007
Messages
2,150
Location
Adelaide, Australia
Godoy

I'd redo the cube mount, do not hard mount it to the engine, & use some other method that will absorb the high frequency vibration that the existing mounting method gives - refer tp page 7-41 Skyview Install manual rev P, the legacy Dynon units Installation manual say the same.

Then I'd check the fuel flow calibration again after the repositioning of the 'cube'.

HTH

Jake J
 

ricardo_godoy

I love flying!
Joined
Apr 24, 2013
Messages
46
jakej.
I will make the change as you explained.
was the first time the mechanic installed a skyview in Brazil, are accustomed to JPI EDM-monitors engine.
thanks.
 

jakej

Well-Known Member
Joined
Oct 10, 2007
Messages
2,150
Location
Adelaide, Australia
jakej.
I will make the change as you explained.
was the first time the mechanic installed a skyview in Brazil, are accustomed to JPI EDM-monitors engine.
thanks.

FYI & others - the sensors that mostly (as there can be exceptions) should not be mounted on the engine are Oil & Fuel Pressure & particularly Fuel flow.

Jake J
 
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