SonexBuilders.net

Exploring the depths of my ignorance here....

I really like the idea of EFI in an aircraft engine, but am unschooled in the pieces/parts required at the engine itself to make that happen. Of the common VW options used in the Sonex line of aircraft, what are my out-of-the-box choices, and what choices do I have if I open the aperature to the retrofit-and-sell-the-excess world? Alternatively, f anyone can provide me with pointers to good sources of info I’d also be grateful.

Alan

SDS (Simple Digital Systems) is probaby the leader in EFI/EI systems for the homebuilt aircraft market, and I know they have sod some systems to satisfied Sonex builders. Their web site is both a tutorial and has info on their products. Their home page: http://sdsefi.com/index.html

Another approach is to buld your own system using MegaSquirt, MicroSquirt, etc. Lots of folsk enjoy experimenting with these systems, and if that is your goal, then have fun with it. I'd be hesitiant to go that route because a system designed for auto hobbyists ("tuners") may not be well adapted to aviation use. Examples:
- The closed loop lambda sensor based systems used in cars doesn't add much value in typical aircraft use, and introduces more failure modes/potential failure modes.
- The "limp home" modes often employed in automobiles are designed to save the engine from damage. In aviation use, the preservation of the engine is generally not as important as providing enough power for continued flight while warning of a problem so action can be taken. This has ramifications in when "limp home" mode is entered and the power levels available in that mode.
- Fault tolerance: There are a lot of things that can go wrong with the hardware and software in EFI/EI systems, though problems are rare in systems that are well designed and constructed. It is a >lot< of work to anticipate all the various combinations of failures and reduce their impact on continued flight. OEM auto makers spend a lot of money and still sometimes get it wrong. I just don't know if the Megasquirt community has the resources and motivation to get this done.

Robbie Knox is also going the EFI route.
viewtopic.php?f=9&t=4612&p=35293#p35293
Not much direct experience here. Between you guys you could write the book on VW EFI in a Sonex. I think it is a cool project.

There was a thread a couple of years ago with all the details of an SDS install on an aerovee. It sounded straightforward and successful. The writer was quite knowledgeable and had a lot of VW experience to share.