boost pump, and fuel flow cal?

[13brv3]

Greetings,

As most of us know, the Facet boost pump that Van's sells creates pulses in the fuel line that cause the fuel flow reading to change substantially. On my previous RV-8, I mounted the flow meter downstream from the boost pump. This time, I mounted it upstream, thinking it would avoid the pulses. I was wrong :

If you leave the boost pump on all the time, could you calibrate the fuel flow accurately, or is the effect from the pump pulses too erratic for a good cal?

FWIW, I've never seen the logic in turning off the boost pump.

Cheers,
Rusty

 

[dynonsupport]

If there are pulses in the fuel line, there isn't any way to calibrate the fuel flow readings to provide a steady instantaneous fuel flow number. However, we have had reports from customers that despite these instantaneous fluctuations, the overall fuel usage computations can even out over a tank of fuel.

Further, there are fuel pulsation dampeners available. We do not sell them ourselves, but check out http://www.matronics.com/ .

 

[13brv3]

Thanks for the thoughts. I know about the stainless sphere dampener, but they say to put it just before, or after the flow meter, and that isn't possible in my installation. If I put it way downstream where I have a location, then it probably wouldn't work.

I might try calibrating the sensor with the pump on all the time. Initially, I could set the plane up in cruise, record the fuel flow reading with the pump off, then turn the pump on and change the calibration figure until I get the original flow reading. I'm still on my 25 mile test flight leash for the next 15 hours, so it will give me something to do

Rusty