T

TrojanDriver

Member
Does anyone have any experience or comment on the Precision Eagle EMS available on Aero Sport Power engines??? I'm preparing to order the engine for my 8 and was tentatively planning on the IO-375(M1S) turning a 3 blade MT prop, but I am at a loss to determine the best electronic ignition solution / combination. My 8 will primarily be used for local light aerobatics and the occasional $100 burger run. Any advice on engine choice is appreciated!!
 
TrojanDriver said:
Does anyone have any experience or comment on the Precision Eagle EMS available on Aero Sport Power engines??? I'm preparing to order the engine for my 8 and was tentatively planning on the IO-375(M1S) turning a 3 blade MT prop, but I am at a loss to determine the best electronic ignition solution / combination. My 8 will primarily be used for local light aerobatics and the occasional $100 burger run. Any advice on engine choice is appreciated!!
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I think your going to have a hard time finding actual installation reports so ill stick my nose in it and give you my useless thoughts.

The EMS has its own mag replacements, fixed timing, no mixture control.
This would be a no starter for me.
I desire variable timing, and mixture control to control heat and LOP operations. This is a pilot workload no question, but in the envelopes I fly, its required for my desired outcome.
If you were only doing $100 hamburgers, a single throttle control might be just fine.
 
Two things

My neighbor has this system and is still in phase one. His fuel flow is high, about 3-4 gallons an hour more than mine. It has limited ability to lean and I'm really concerned about how it works in the extreme heat we have in AZ. He said it all weighs 18 pounds with the extra battery required. It is electrically dependent.

Second point, have you looked at the Whirlwind prop? A couple of my neighbors have had MT props and had problems. One on a Lancair another on a RV.

As Kahuna noted, mixture control is very important!!
 
Eagle EMS

I have an Eagle EMS system on my IO-320. I am not flying yet so I can't give you any details on actual fuel consumption. Precision Airmotive claims you should be seeing a fuel savings. It is based on the programmed amount of fuel for each combination of temp/pressure/rpm and all settings that are being measured. If your neighbor is not getting favorable results, they should contact Precision and talk through the issue.

As for leaning, I have installed a potentiometer that allows you to lean out to LOP after reaching cruise.
 
Eagle EMS

Thanks Kahuna and RV7Guy, you raised the same concerns I was having, especially since I don't see much 'straight and level' flying in my 8's future! What would be your thoughts on Ligit Speed Plasma III or another system?? Maybe I'm too hung up on electronic ignition, but that seems to me to be one of the benefits of this class of airplanes (better technology without the delay and cost of certification). I will definately look at Whirlwind props, I had an MT on an Extra 300L and had no problems with it (plus there's nothing like the looks of a 3 or 4 blade prop on a little 'fighter').
 
I see this is your second post.
Electronic ignitions have been bantered on these forums for years.
I recommend you grab the search function and search away.
Lots of folks have given their time and effort on posts there that you will find informative.
 
Kahuna said:
I see this is your second post.
Electronic ignitions have been bantered on these forums for years.
I recommend you grab the search function and search away.
Lots of folks have given their time and effort on posts there that you will find informative.
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WILCO.....and thanks.
 
Eagle EMS

The Eagle EMS is a VERY configurable system. It DOES have variable timing capability and mixture can be programmed from very rich to very lean. Aerosport or G & N do initial calibration on their dynos and will probably want to deliver the engine with fixed timing (a good idea while you are proving your cooling system) and conservative mixture settings--which you can tweak slightly with the provided lean pot. The base calibration adds extra fuel if CHT's go over 400. Because each homebuilt is different, the owner gets to refine the calibration tables using a laptop. I don't know how much leeway Precision gives the buyer here. People with strong opinions, but little knowledge, could easily destroy an engine.

Precision has some very good info at: http://www.precisionairmotive.com/eaglesupportdocs.htm . Theory of Operation spells things out in an easy read.

Weight is supposed to be about the same as regular fuel injection plus your desired backup battery--anywhere from two pounds to whatever. You provide your own fuel lines, and Precision builds a custom wiring harness based on your measurements.
 
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EAGLE EMS REPORT - after 235 hours on it

Wow -- its hard to believe the speculation that I see, much of it erroneous. How about someone who has actually flown behind this system for 235 hours tell it like it is?

Mine was the first EAGLE EMS system that Aero-Sport sold. Unlike an automotive EMS, there are two completely redundant processors in the EAGLE EMS, along with redundant sensors. The redundant processors each have stored in FLASH memory that must be individually set up, and should have identical tables. 7 months after I started flying it, I discovered that the secondary side was set up for a 360 cu in engine. After 100 hours, I decided to move my A/F tables leaner (from 10.0 to 12.2 A/F on the O2 meter), and I expanded the range of my A/F control pot to get to 15 A/F. I think I did best by leaving the system run rich until the engine was broken in. Another parameter I changed was setting the system to automatically put me in maximum power (12 A/F) when the RPM is above 2400, thus ignoring the A/F pot setting -- nice feature.

This system has the ability to modify any parameter you want, including engine timing, which has a table that steps 100 RPM at a time, including best power Air/Fuel ratio to all altitudes (wide band O2 readings are constant all the way up), and the A/F ratio can be dialed in, wherever you want it, with a single control -- you set it and you get that A/F mixture from altitude all the way down (or up).

Having 235 hours on this system, I think I have more hours than anyone else behind the EAGLE EMS on a Lyc 320engine on an RV-9A (still unpainted). Take a look at my trip to KGHG from KDCU yesterday on www.aprs.fi, call = wa8vwy-7, tell it 12 hours. On that entire trip, I got 6 GPH (including climb-out to 12,500). On cruise at 12,500, I get between 142 and 150 KTAS (on Dynon 10A) at 2200 RPM and 5.7 GPH. If I am not in a hurry, I drop the RPM to 1900, drop to 132 KTAS, and drop below 5 GPH. I like the high altitudes - little traffic up there, and you go faster on less fuel.

Bottom line: this system is very well thought out, and is a real professional implementation of an EMS system that is specifically designed from ground up for our unique airplane application. Precision Airmotive even made their own injectors -- all stainless steel, rather than part plastic automobile injectors.

Now, I invite anyone who is building an airplane and is considering this system, to come to KDCU and fly with me.
 
EAGLE EMS REPORT - after 235 hours on it

Wow -- its hard to believe the speculation that I see, much of it erroneous. How about someone who has actually flown behind this system for 235 hours tell it like it is?

Mine was the first EAGLE EMS system that Aero-Sport sold. Unlike an automotive EMS, there are two completely redundant processors in the EAGLE EMS, along with redundant sensors. The redundant processors each have stored in FLASH memory that must be individually set up, and should have identical tables. 7 months after I started flying it, I discovered that the secondary side was set up for a 360 cu in engine. After 100 hours, I decided to move my A/F tables leaner (from 10.0 to 12.2 A/F on the O2 meter), and I expanded the range of my A/F control pot to get to 15 A/F. I think I did best by leaving the system run rich until the engine was broken in. Another parameter I changed was setting the system to automatically put me in maximum power (12 A/F) when the RPM is above 2400, thus ignoring the A/F pot setting -- nice feature.

This system has the ability to modify any parameter you want, including engine timing, which has a table that steps 100 RPM at a time, including best power Air/Fuel ratio to all altitudes (wide band O2 readings are constant all the way up), and the A/F ratio can be dialed in, wherever you want it, with a single control -- you set it and you get that A/F mixture from altitude all the way down (or up).

Having 235 hours on this system, I think I have more hours than anyone else behind the EAGLE EMS on a Lyc 320engine on an RV-9A (still unpainted). Take a look at my trip to KGHG from KDCU yesterday on www.aprs.fi, call = wa8vwy-7, tell it 12 hours. On that entire trip, I got 6 GPH (including climb-out to 12,500). On cruise at 12,500, I get between 142 and 150 KTAS (on Dynon 10A) at 2200 RPM and 5.7 GPH. If I am not in a hurry, I drop the RPM to 1900, drop to 132 KTAS, and drop below 5 GPH. I like the high altitudes - little traffic up there, and you go faster on less fuel.

Bottom line: this system is very well thought out, and is a real professional implementation of an EMS system that is specifically designed from ground up for our unique airplane application. Precision Airmotive even made their own injectors -- all stainless steel, rather than part plastic automobile injectors.

Now, I invite anyone who is building an airplane and is considering this system, to come to KDCU and fly with me.
 
On that entire trip, I got 6 GPH (including climb-out to 12,500). On cruise at 12,500, I get between 142 and 150 KTAS (on Dynon 10A) at 2200 RPM and 5.7 GPH. If I am not in a hurry, I drop the RPM to 1900, drop to 132 KTAS, and drop below 5 GPH. I like the high altitudes - little traffic up there, and you go faster on less fuel.
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Jim - Thanks for the report! I am hoping to be in the air by next Summer, with my own Eagle EMS. I am encouraged by your numbers, as I will also be running a Lycoming 320 from Aero Sport on a 9A. One question... are you fixed pitch or constant speed prop?
 
Constant speed prop

I'm using the Hartzell CS prop that was ordered thru VAN's. You need the CS prop to do the EAGLE EMS justice and get that sort of numbers. I climb out at 2600 RPM and throttle wide open all the way to 12,500 -- I see 11.5 GPH at low altitudes, and it drops to about 9.5 at 12,500. I leave the throttle wide open (19" MAP) and pull the prop back to 2200 to 2250. Then I twist the A/F control to full lean. The EGT rises about 125 degrees, the A/F rises to about 15, and the fuel flow drops from 9.5 to 8 by pulling the prop back, and further drops below 6 by setting the A/F control to full lean. I use the Tru-Trak auto pilot in altitude hold, and the altitude is locked dead on (I love that auto pilot). Then I watch the D10A TAS output -- with gross weight, it will be around 141 to 143, after burning off half the fuel, it will rise to maybe 144 to 145, and solo with quarter tanks, it sometimes hits 151. I set my EAGLE up such that at full lean, I only go to 15 A/F, which might not be peak, and is definitely not lean of peak -- because if I turn the control slightly richer, the EGT begins to drop - if it were lean of peak, the EGT would rise first.

One suggestion: don't install the Innovative wide band O2 sensor permanently because the sensor only lasts 50 hours with leaded fuel and costs $805 to replace -- so I suggest a temporary installation, and once you have the EAGLE set up like you want it, then abandon the sensor (or plug the bung) and sell the slightly used A/F system. I am on my third sensor that I installed 20 hours ago, and I plan to remove it and recover the panel space. I did not have it running for almost 100 hours, and when I put a new sensor in, I found that nothing had changed, so I wasted $80, and I don't think I can improve the EAGLE settings. It is fun to look over and see that the EMS is holding a constant A/F all the way up to altitude at maximum power, so the entertainment value might be worth $10.

Another suggestion: install your own LED annunciator lites for the two red LEDs on the EAGLE system directly in front of you, so you can see them (they will never be on unless you have a problem), and install the yellow LED somewhere out of the way, not in front of you -- you only need glance at it after you start the engine, and maybe again just before you shut down, and it is flickering on and off all the time if the EAGLE EMS battery is OK. If you do this, then you will not install the big honking LED annunciator that Precision provides (my only negative comment on the system).
 
Jim-

Thanks for the great write up. I have a three bladed Catto prop. Now I am wishing I spent the extra money and went CS. I finished my panel a couple of months back. Yes, I put the big LED indicators in the panel as they came. Also a decision that I might do differently on my 'next' plane. You can see it here on the left side of the panel between the starter switch and the LRI.

IMG_5618.jpg
 
Reply

Very nice panel you have. Even the big LED EAGLE annunciator looks fine there, where you can easily see it. I put mine way off the the right side, where I can't easily see it, so I need to install two red LEDs on the left side and run them in parallel with the originals, leaving the original where it is.

If you get close to Huntsville, AL before you fly, please contact me: 256-345-3657.
 
If you get close to Huntsville, AL before you fly, please contact me: 256-345-3657.
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Jim-

I have customers for work in Nashville and Cinncy. Maybe I can swing by on one of those trips. I will give you a ring if I am in the area. Thanks.
 
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