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Switching from a Mag to a Surefly

stneki

Well Known Member
Patron
I decided to switch out my mag on my O-360 to a Surefly. My panel has GRT 4000 EIS that currently picks up the RPM from the P-lead with a resister inline.
What do I need to do to be able to receive the correct RPM signal with the Surefly?
 
Since (I gather) you still have one conventional mag, the easiest thing to do is to move the resistor pickoff to the remaining mag, presumably hooked up at the ignition switch. If you want a signal from the Sure Fly, too, I don't know how to get it but I'll bet there's a way (my EIS 6000 has separate connections to both mags, I set one primary but it defaults to the other if no signal, e.g., during mag checks the RPMs do not go to zero on one mag).
 
If you want to get a tach signal from the Surefly, you'll have to get a Tach2, tach generator board, from Surefly.aero. $162, as of today. I installed one and it works great.

Merrill
 
I decided to switch out my mag on my O-360 to a Surefly. My panel has GRT 4000 EIS that currently picks up the RPM from the P-lead with a resister inline.
What do I need to do to be able to receive the correct RPM signal with the Surefly?

This is a response from grt on similar question:

Hi Butch,

Your EIS is capable of reading from mags and some electronic ignition
systems as is. Unfortunately, the tach signal from the Surefly is not
compatible with the EIS, old or new, without the addition of a "tach
converter" box which Surefly also manufactures.. Alternately, you could install a UMA tach sensor in you mag, which will provide a tach signal whenever the
engine is running, regardless of whether the mag it is installed in is
active or not.

Eric Bartlett
GRT Avionics
 
SureFly Tach Signal

Recently did my first SureFly install on a RV7 with IO-360. The SureFly replaced the left side Slick impulse mag. This plane has Dynon glass. After much experimentation with various resistor combos and numerous conversations with Dynon & SureFly I was unable to get a suitable Tach signal off the SureFly that the Dynon Tach could use. There were several options at this point, 1- let the right mag P-lead signal run the Tach and operate without a Tach when running on just the SureFly. 2- (the option I went with) install the UMA pickup in the right mag vent hole. It uses the rotor in the Right mag to interrupt the +12v signal which gets connected to the Left side Tach input of the Dynon. 3- use the UMA unit that mounts on the Tach drive fitting on the accessory case. It works the same way as option 2 by interrupting the +12v input. 4-SureFly makes a unit (another box) to convert the Tach signal to something your glass panel Tach can use.

Don Broussard
RV9 Rebuild in Progress
A&P, IA, ATP
57 Pacer
 
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I installed a Surefly last year replacing the left impulse mag and yes I have no tach reading on my Skyview during mag checks when on the Surefly. I am ok with this as I can hear the engine rpm during runup; and during normal operation the tach reading from my right mag works fine. No need in my opinion to spend time or money to fix this minor issue.
 
Tach signal is literally the only thing preventing me from buying a Surefly today. Certainly they are aware and are planning a design change to play nice with modern efis and engine motor equipment. At least that's what I keep telling myself. I don't want to buy one only to find out in a month they're releasing an updated model.
 
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