D180 Fuel Flow


I love flying!
Jan 28, 2016
The installation manual for Dynon D180 says that for Rotax carburated engines (We've got Rotax 914) with return fuel line to the tank, for correct fuel flow numbers I need to use matronics' differential module. So I've already have FFDM-1 differential module with one 'Red cube' FT-60 and one 'Golden cube' FT-90. There are three questions:
1) Is it possible to use FFDM-1 with Dynon D180 and connect them like just a usual FT-60 'Red cube'? Or there is a special instructions?
2) Do I need to use second FT-60 'Red cube' instead of FT-90 'Golden cube'
3) Even if 1 and 2 are correct and it possible, I wonder about the K-factor, how to calculate it?


Dynon Staff
Staff member
Jan 14, 2013
Woodinville, WA
1) The matronics computer does simple subtraction. And I think that implies - unless it has its own setting - that the fuel flow sensors must basically "match" in terms of K-factor. The FT-90 and FT-60 don't (they have K-factors that are about double one another), so I think you'll need to pick one model and pick another of those up.
2) Or vice versa. Two FT-60s or two FT-90s, basically.
3) Once you have two like sensors installed, start with the base k-factor specified by the sensor model, and then adjust the Dynon k-factor as if you have just one sensor installed.