Avid Flyer Venturi Installation

[nlappos 413]

I am thinking of putting a Directional Gyro in my Avid MK IV, and wonder if someone has ever installed a venturi on their Avid. Any info would be appreciated. Thanks!

[Av8r_Sed 82]

I did on my Kitfox.  12" venturi on the belly next to the radiator and the proper vacuum filter to the instruments (both a DG and AI).  I didn't install a regulator.  It never really worked for me with my typical 75 mph cruise.  Eventually I decided all that weight and drag was useless to me and I removed it all.  I've never missed it.

[Av8r3400 1178]

My mangy had a venturi on it but no gyros.  It was mounted to the rear cowl on the pilots side.  

I still have it if you want, but suspect Paul's results would be the same for you. 

[nlappos 413]

Thanks guys. I bought a used one on ebay (I should name my airplane The Ebay Evader). I will rig it on a board out my car window and calibrate its draw vs speed to see if it is worth it. 

[EDMO 1078]

I had one with the DG on my Ercoupe and at 105 indicated airspeed it worked good.   Never saw an Avid or Fox with one, but really haven't been looking that close.  EDMO

[1avidflyer 1983]

Here is an Avid in Germany with a venturi on it.  Don't know if of how well it worked, but it's there.  Jim Chuk https://www.youtube.com/watch?v=037_ha2y5XQ

[FoxDB 17]

I installed one on my mod 1 Kitfox with an AH and it has worked well. I don,t see a need for DG as GPS works very well for that.

[nlappos 413]

I built a simple rig to test it out my car window, Here is the data. The venturi is a big one, looks like the 4" one at Aircraft Spruce, the horn itself is 10.75" long. At 75 mph it draws a healthy 4.3 to 4.4" hg, At 70mph, 3.3 to 3.5, at 80, 4.8 to 5.4"(note my car speedometer calibrates 2 mph slower than indicated at 75 mph). Those who say it had significant drag are quite right, I had to really push on that stick, estimated at 15 lbs of drag force, probably a 4% increase in drag/reduction in range.

 

 

Edited 25 Jan 2016 by nlappos