SureFly Electronic Ignition

[DaveS1900]

Question for those that have Surefly,
I talked to a mechanic who didn't recommend surefly because they had experience with a situation where one of the electronic ignitions took out both EI's. I was all set to put at least one on, but if the mechanic doesn't embrace it, then it's hard to move forward.
Thoughts?

[MarkA]

Dave,

Was your mechanic talking about replacing both mechanical mags with SureFly electronic ignitions?

SureFly just received FAA approval to replacing both mags with SIMNs (which requires a separate battery backup) a few months ago. I'd be surprised if the dual electronic ignition failure he is referring to was related to a SureFly installation. I'd be interested to hear more details if that was in fact the case.

Thanks

[DaveS1900]

Yes I agree it probably wasn't surefly. It seems like the Cirrus guys have dabbled in electronic ignition and it didn't go well. That's just a guess.
Dave

[MarkA]

With either a dual or single SureFly installation, the two ignition modules are completely independent of each other so if one fails, it should have no impact on the other.

My initial impression is that the cost vs benefit of a dual SureFly configuration seems a little questionable. The additional hardware cost for two SureFly SIMs (currently $1,755 each) plus the battery backup needed for one of the SIMs (currently about $1,700 for TCW's battery + installation kit) plus the more complicated installation costs would be quite a bit more than the relatively simple single SureFly SIM installation.

The only real benefit of a dual SIMs vs the left-SLIC-mag-right-SIM setup is the elimination of the 500-hour service needed for the remaining SLIC mag. Hot and cold starts would be basically the same for both configurations – all 8 plugs would fire in both configurations. There may be a slight cruise fuel efficiency gain since both SIMs would advance the spark, but I suspect it would be pretty insignificant vs the left-SLIC-mag-right-SIM setup installation.

[MarkA]

The table below has some initial pre and post SureFly installation performance numbers measured on my DA40 XLS. The data was generated using FlySto.com’s “Insights” after uploading the G1000 flight logs for all 2020, 2021, 2022 and 2023 flights – a total of about 300 flights.

A single SureFly SIM with variable timing enabled was installed in place of the right Slick magneto mid-year in 2022. The data from 2020 and 2021 can therefore be used as the pre-Surefly installation performance numbers and can be compared with the 2023 post-SureFly installation performance numbers, the first full year of flights with the Surefly installed. You can ignore the numbers from 2022 since they represents only a partial year of Surefly flights.

Other than the SureFly installation, there were basically no other changes made to the plane or how it was flown in terms of the number of hours, mix of cross-country vs local flights, leaning procedures, etc. during this 4-year period. The performance differences seen here can therefore be attributed pretty much exclusively to the SureFly.

As shown in the table, there was a little over 8% drop the measured cruise fuel consumption after the SureFly was installed with no change in the cruise TAS.

As with all performance numbers, "Your actual mileage will vary" .

[steve_falconer]

My overall fuel efficiency is similar at 7.48 gallons per Hobbs hour across 66.1 hours if that helps anyone else, but gotta love that G1000 data! Thank you! I get 8.62 gallons per flight hour using the VM1000 tach time across 57.4 tach hours. These numbers include climb, descent, cruise across 32 flights and Hobbs includes taxi. My home field is towered and a bit of a taxi. It’s not so easy to get great data with a VM1000, so I track it the old fashioned way with hours and fuel purchased.

I guess I should look to my G500 for log cruise speed info now…. Hmmmm…..

Mark I was wondering if have you done an inflight mag check at cruise to test mags and noticed it runs rougher on the non-Surefire magneto? I’ve been VERY happy with mine, but had noticed when leaned for cruise with Surefire running smoothly with advanced timing that when switching to the other normal mag that it does run a lot rougher. I guess I should expect that since running leaner like that the flame won’t develop with a colder spark later in the cycle when the mixture is leaner. That has lead me to think about doing both magnetos, but the complexity of the install is making me second guess. I’ll need to decide to send the mags for overhaul or replace with a second Surefire after Summer.

[dant]

That's not a small improvement... looking at a recent flight of mine, it's about 5 gal to get to a 9k cruise altitude from KPAE (600ft). 35 gallons left + a 1 hour reserve:
at roughly 8.3 gives -- 3.2 hours of cruise
at roughly 7.6 gives -- 3.6 hours of cruise

that's an IFR alternate ~50 miles away, likely opening up a lot of IFR flights that weren't available before for us 40g tankers.

[blsewardjr]

I have the SureFly as well. I didn't think it was doing much. However, I did a quick comparison of a small (4-5) sample of X-country flights with the same power in cruise (65% ROP) pre and post SureFly. There was an average savings of .5 GPH measured in Hobbs and and .7 GPH in Tach for an overall average savings of .6 GPH. Percent savings was 6.1% overall.

[Rich]

I've been keeping a log of fill-ups (including associated Hobbs and Tach hours) over a number of years.

SF installed 2020. Crude as they are, Here are the numbers I see:

2016-2019: 8.1 g/Hobbs hr, 10.6 g/Tach hr.
2021-2022: 7.2 g/Hobbs hr, 9.6 g/Tach hr

0.9/1.0 g/hr by each measurement. Not by any means a controlled experiment but a large sample size including various types of flying I have come to use during those time periods. There were no modifications during this time that might credibly have affected fuel consumption.

I tend to run ROP/WOT/2400 RPM cruise and works out to 143/144 KTAS for most flying. I have operated for all this time period from a home base at 3250 ft. elevation, so I'm almost always operating at some degree of spark advance.