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EFII?

J

jump4way

Well Known Member
I'm at a decision point for my RV-8 project and am curious to hear opinions on the EFII system vs mechanical injection systems.

As I see it the EFII system pro's are:
1) increased performance. They mention 10% increase but I'm not sure how you can truly quantify that.

2) Improved hot starts. I live in Arizona and am concerned about hot starts. I've never owned a fuel injected aircraft so I'm uncertain how large of a benefit that will be over mechanical injection.

3) The ability to use any fuel 91 octane or greater with or without ethanol. With the rising cost of avgas along with the uncertain future of 100LL that might be a nice benefit.

The cons as I see it are:
1) Electrically dependent aircraft. Obviously the electric system has to be very sound and a backup has to be incorporated. I'm leaning towards a backup alternator and single battery at this point but not certain.

2) Field serviceability is a concern as there is much more knowledge and available parts I would guess for mechanical systems.

There has been very little real feedback from the field on the EFII systems to help aid in my decision so I'm looking for any opinions from those that have installed the system or those that went down the same thought process as I and decided differently.

Thanks in advance for any information.
 
It's Okay

?Electrically dependent aircraft . . .?

Redundant Electrical System = EFII Bus Manager (or the equivalent):

http://www.flyefii.com/bus_manager/bus_manager.htm

?Field Serviceability . . .?

Spare EFII Components are readily available at local auto parts stores or overnight from EFII; in the unlikely event you need a spare.

Opinion: The components, mounting, and integration of the EFII fuel injection and ignition systems are well-proven and readily available. In terms of reliability, the EFII itself is not a worry, but, yes, the electrons must keep flowing so the reliability of your aircraft?s power system is crucial. Hence, the need for a Bus Manager or something similar. A robust, redundant electrical power system is needed for any ?electric? aircraft.
 
As Bill Said, the system, both ignition and fuel is base don automotive technology and leveraged on high quality automotive components and backbone. I've said from he beginning, with regards to the system we are putting in out 10, that you don't see cars stopping on the side of the road due to ignition or fuel system failures....
Yes, you do need a sturdy electrical system with redundancy, (2 batt-2 alt, 2 alt-1 batt, 2 batt-1 alt) theres a lot of different way to accomplish it and opinions vary widely on the "best". Personally we have 2batt-2 alt, that are essentially isolated form each other yet, via the bus manager can power the system should either fail. With a gear driven #2 alternator powering the essential buss, and therefore the fuel and ignition system, even a belt breakage wouldn't stop the engine.

Things to think about for planning:
Return fuel lines to the tanks
Location of dual fuel pumps and filters (for servicing)
Dual ECU?

The system actually installs very easily. and while my engine was dyno tested on the system and ran smooth as butter, we are not in the air just yet
 
Aloha jump4way
I've got over 400hrs on the EFII setup on my Rv7
It's a good system once you setup the fuel maps
You DO NEED a dual battery single alternator setup at the minimum as the setup is highly electrically dependent. If you use the Bus manager setup Robert sells it is pretty straightforward with no surprises
if you're going to go with a dual alternator tell him before you decide to do it so he can set the bus manager up for two alternator set up for a split electrical bus
It's pretty cool once you have the fuel map set to be able to take off /climb Cruise / land without touching the Mixture knob once😎
Give me a call if you want more details on the system
Lee
seven zero seven -863-1121
 
I've got 460+ hours on my RV-7a and all of that time is behind all-electric engines - the 1st 360 hours was a Subaru (also with EFII), and now a Barrett-built I-O 360. When I changed to the Lycoming clone, there was absolutely no doubt in my mind as to what fuel and electrical system I was going to have: Roberts Paisley's EFII solution.

I have dual batteries, dual coil packs, dual ECU's, duel fuel pumps, dual busses, and also Robert's Bus Manager. One ECU/coil pack fires the top plugs, and the other ECU/coil pack fires the bottom plugs. At runup, I can test either ECU/coil/pack/plug setup with a toggle-switch. Either set of plugs provide such an intense spark that you barely notice the engine running on half the spark plugs. Using the Bus Manager, a failure of Fuel pump 1 automatically fails to Fuel Pump 2, and you can also test the fail-over circuitry at runup toggling a switch. The engine starts easily, either cold or hot, no issues with vapor lock, and I rarely touch the mixture knob after startup. I just fly the thing.

I do have a standby alternator that will be installed shortly, and like Lee (jetmech) indicated, talk to Robert about using dual alternators and that you actually have a choice of running each alternator output to a separate bus using his Bus Manager. He can help you weigh the pros and cons. It's best if he knows ahead of time about dual alternators, but even if you decide later to change things -- no big deal, just talk to him about the change and get it sorted out. Robert's products are top-notch, well machined, and he stands by what he does. Call him if you have any questions about the setup you are thinking about, and he's sure to provide helpful advice.

Michael
RV-7a, Barrett I-O 360 (Dyno @ 185 HP on std intake/electrical), Vetterman X-over exhaust, Sam James Cowl/plenum, Robert Paisley's Dual ECU EFII & Bus Manager, Constant Speed Prop
 
jump4way said:
As I see it the EFII system pro's are:
1) increased performance. They mention 10% increase but I'm not sure how you can truly quantify that.
Click to expand...

Maybe if you're upgrading from a carburetor.

2) Improved hot starts.
Click to expand...

Should be superior in all respects.

3) The ability to use any fuel 91 octane or greater with or without ethanol.
Click to expand...

Octane requirement has nothing to do with the fuel metering method.

The cons as I see it are:
1) Electrically dependent aircraft.
Click to expand...

Yep.

2) Field serviceability is a concern as there is much more knowledge and available parts I would guess for mechanical systems.
Click to expand...

EFI has been around a long time in automotive applications, so I'd be surprised (and cautious) if a professional mechanic didn't understand the fundamentals. No difference in parts availability.

There has been very little real feedback from the field on the EFII systems to help aid in my decision so I'm looking for any opinions from those that have installed the system or those that went down the same thought process as I and decided differently.
Click to expand...

Dude! The VAF search function is your friend!
 
Thanks a lot for the great feedback. You guys have put a few of my concerns to rest.

It seems most of you are using the Bus manager setup, perhaps that is the direction I need to go. I had been planning to follow along with Bob Knuckolls Z13/8 as it gives me a reasonable plan to follow for the entire main power distribution where the Bus Manager installation guide leaves a lot of the detail out for builders starting from scratch. Do any of you have a wiring diagram that you followed that incorporates the Bus Manager that you could share?

One thing that is hard to believe at this point is how little negative feedback I have found of this system ( I have found none up to this point ). I'm not saying I like negative feedback but in the world of the internet it seems to rare to not find negative reviews of anything. I guess the fact the system is fairly new with a lower number of airplanes flying plays in to that, or it could be that it is as good as advertised and there are nothing but happy customers.

Now if I can just figure out this electrical thing I would be in business.

Thanks for your time.
 
I'm working on converting my electrical diagram from paper to Visio, and will post it once it's done. Bus Manager with VPX Sport, dual everything as others have above. Designed it with input from Chad at Vertical Power last week at Oshkosh.
 
My electrical system has morphed over time but was originally, loosely based off of Bob's Z13. It's will be good to see what is produced from the previous post by Scott for something that is more of a clean-sheet start for an electrical diagram -- which seems more of what you need right now.

As far as negative press for Robert's EFII system, true, there is not much if any out there. If you really want to find some, how about this:

- Whenever I try to reach Robert for a question, or comment, he always picks up, or answers the email in really short order! ...Now, how am I able to get worked up about that! Jeez, I really need something to get worked up about, and Robert just does not play fair in this regard! :D

Michael
 
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There are two things that concern me regarding a complex setup like what you are thinking about.

1. Should something fail, do you or a subsequent owner understand the systems enough to flip the correct switches to keep it flying? A sound design will not require intervention. (My business partner has an all electric airplane and has a number of engine out landings, and all but one could have been avoided had he flipped the correct switches while in the air.)

2. Weight. The extra batteries, alternators, controllers. etc. all add weight and reduce useful load. It is up to you to build the plane you want for the mission you have in mind but if complexity reduces functionality, then maybe you should take a second look at your options.

Don't get me wrong, I really like the idea of EFII in our planes but am flying a carb and dual P-mag electronic ignitions and am very happy with the set. Only once have I had a rough running engine due to heat issues and my electric fuel pump solved that problem.

Good luck with your selection!
 
I run an Airflow Performance mechanical fuel injection system, magnetos and dual electric fuel pumps.
I have had one primary electrical failure, the alternator power output wire compression fitting failed due to vibration.
I noticed the low voltage (12.6V) as I approached a local airport where I intended to visit some EAA Chapter buddies. So I diverted to the home drome, 10 minutes farther and landed with 12.2V.
That was on a 5+ year old PC680 battery, which was quickly replaced. Also the output wire was remade with more service loop and tied back.
I have rebuilt my RV-8 to be one of the lighter ones, shaving off over 70 lbs from the turbo Mazda configuration.
I am opposed to excess system redundancy, the complication adds a risk factor all it's own, as Bill pointed out in the previous post.
But my system requires vigilance due to the fuel pumps both requiring electricity.
I may install the mechanical fuel pump after all. It weighs about the same as the 2nd electric pump and makes the propulsion totally independent from the electrical system. This eliminates the need for all those back up alternators, batteries and buss transfer systems in a daytime VFR acro & cross country plane.
So that's a counterpoint. I ran a Real World Solutions EFI system on my Mazda power plant. It worked fine too and was not the reason I removed the Mazda.
Have fun, the only other thing I could add is to avoid complication, which always delays completion and the first flight. I really blew it with that one!
 
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N941WR said:
There are two things that concern me regarding a complex setup like what you are thinking about.
Click to expand...
Very good points!

1. Should something fail, do you or a subsequent owner understand the systems enough to flip the correct switches to keep it flying? A sound design will not require intervention. (My business partner has an all electric airplane and has a number of engine out landings, and all but one could have been avoided had he flipped the correct switches while in the air.)
Click to expand...
Agreed--a failure of a pump, battery, or alternator should not require immediate pilot action to keep the engine running. If possible there should also be some kind of warning to the pilot that it occurred--we don't want people flying around with "hidden" failures--but the critical systems should still be receiving power even after a failure. I don't think this necessarily needs to be extended to all post-failure actions; for example, I would think it acceptable that turning off non-essential equipment (load shedding) is still a manual function. Depending on the failure, it's still important, but it's not something that you would need to do right now so your engine doesn't quit, either. And, being able to selectively turn off equipment means you could preserve items that may be critical under some conditions but not in others, like your IFR nav equipment.

2. Weight. The extra batteries, alternators, controllers. etc. all add weight and reduce useful load. It is up to you to build the plane you want for the mission you have in mind but if complexity reduces functionality, then maybe you should take a second look at your options.
Click to expand...
It depends how you define functionality, I think. I'm also planning on an EFII install, and I know that the redundant generator and battery will add weight and some complexity to the electrical system. Part of that weight I should be able to make up for with lower fuel burn, and part of it I was already going to have because I'm planning on eventually being IFR capable and need redundancy for that.
I also consider some of the advantages of EFII--ease of starting, far less susceptibility to intake icing or vapor lock, mogas compatibility, and the strong possibility of being able to program a fuel map so I don't have to fiddle with the mixture--to be worth the extra complexity. I'm willing to spend the time up front on design, installation, and testing*, and a couple of extra pounds in empty weight**, in order to realize those benefits later.

Others feel differently on the matter. It's not a right or wrong thing. But it's important that whatever you choose, you make the decision with full knowledge of the advantages and limitations of that choice, and the assumptions behind its design. Don't choose the older, "traditional" standard choice just because it's older; take the time to think about why that was the choice when it became the standard. And don't pick the new thing simply because it's the new thing; learn the details of what's different and what its limitations are.



* then again, I work on complex aircraft systems for a living, so perhaps I'm more comfortable than most...

** I'm also prepared to spend a few extra pounds on insulation, cabin furnishings, heated seats, etc. to keep my wife happy when flying with me. I'd think that's definitely an operational benefit ;)
 
Solutions

A. Weight (. . . just add dollars!):

# 1: EarthX LiFePo4 Batteries (ETX680 is 3.9 pounds; PC680 is 15.4 pounds)

http://earthxmotorsports.com/product-category/experimental-aircraft/

#2: B&C SD-8 Dynamo (2.9 pounds)

http://www.bandc.biz/alternator8ampshomebuilt.aspx

B. “Should something fail, . . . “:

# 1 (by far): Education & Training.

# 2: Something like the Bus Manager or similar electrical power system architecture which auto-routes available power to the essential bus (electronic ignition & fuel injection) as well as auto-activates the backup fuel pump if fuel pressure falls.

http://www.flyefii.com/bus_manager/bus_manager.htm
 
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