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Ignition Systems Questions

gregfuess

Well Known Member
So there's been a lot of discussion on the -10 section of VAF about this, and it's something I would like to know a lot more about, since I have time to change the details of my Thunderbolt order, which included the PMags and Airflow Performance.

There's something called SDS EFI/EI that is supposed to reduce propulsion to a single lever, if I can read their website correctly (it's a little disorganized). The system is pricey at over $5k, and it's benefits aren't entirely clear, other than reducing propulsion from two levers to one, which would be nice.

Can anyone lend a little clarity to this for me?

My wing kit is scheduled for crating in June/July, and my mind won't sit still for the wait...
 
Ignition

The determining factor for me is to ask myself: You are in E. Podunk and a mag is dead. Call Aircraft Spruce and you can probably have a mag the next day. System X, who knows? Maybe a day, maybe a week or month.
The single lever system sounds great until it fails. At this point few if any know how to troubleshoot or fix them.
 
I am running the SDS system and am quite pleased with it.

It does come with a basic fuel and ignition map in the ECU, but as each plane is a bit different you will need to fine tune things yourself to get the max out of it.
 
I placed an order for the IO-390 last week and wrestled with this question as well. The SDS system is nice. Essentially electronic fuel injection and electronic ignition from the automotive industry. Among other benefits, one of them as you pointed out is to remove the mixture knob. It uses an electronic control unit (ECU) to constantly adjust the fuel mixture to the conditions, thus optimizing engine performance. Also, because it's a pressurized system, there is a fuel return to the tanks that negates any need for a gascolator (if you want that). The electronic ignition system is also nice but does require a constant electrical supply to keep the engine running.

If you order the Thunderbolt w/o Fuel and Ignition, you save about what the SDS system costs. So it's basically a wash. Overall, I think the SDS system is well established and given the reliability of automotive systems, I suspect it's pretty robust as well. EFII really does make a lot of sense and is standard in cars, so why shouldn't it be in planes too?

I will point out that in the end I ordered a non-TB engine with Pmags. So I'm not sure what that tells you...
 
Price SDS up .......... It is cheaper than fuel injection and mags :D

We are installing it in our 10 - Ross is great to work with, SDS is bringing our ditch pump engines into the 21st century !!!
 
SDS is not “automotive” system. It is purpose built and well evolved for Lycoming and various other engines. It is derived originally from their race car systems, also purpose built, well evolved, and very successful. There are numerous threads here discussing the advantages and requirements of any electronic fuel injection (EFI) and electronic ignition (EI), SDS has both and you can install both or either.

Ross offers a complete system for many motors. He is an absolutely super guy to work with.

Check it out.
 
EFII

Running EFII System 32 in my -10 and couldn’t be happier.

Starts like a car hot or cold, engine tuning on the fly. Works great.
 
SDS is not “automotive” system. It is purpose built and well evolved for Lycoming and various other engines. It is derived originally from their race car systems, also purpose built, well evolved, and very successful. There are numerous threads here discussing the advantages and requirements of any electronic fuel injection (EFI) and electronic ignition (EI), SDS has both and you can install both or either.

Ross offers a complete system for many motors. He is an absolutely super guy to work with.

Check it out.

If the cost is a wash, could you answer some more questions?

How much time do you think installing it on your engine added to your build time? Do you think that your engine runs better with it? There's something about an alternate power supply for it, did you install that, and how do you power it? Does the SDS system come with comprehensive installation instructions?

Appreciate your thoughts.
 
Greg, we have a number of RV-14s flying with SDS. I can put you in touch with one customer who has several hundred hours on his and he'll give you the straight goods.

Main advantages of EFI over mechanical injection and mags are no hot start issues, little fiddling with mixture and no more mag maintenance. You can also trim the fuel to each cylinder in flight to balance AFRs in each cylinder at any power setting for maximum efficiency.

Efficiency and power gains are minimal over well set up legacy engine controls (with balanced injectors) unless you do a lot of high altitude flying LOP where the EFI fuel metering accuracy and variable ignition timing comes into play more.

Main disadvantage would be that you're electrically dependent so need a well thought out backup power system- either a 2nd battery or alternator or both.

EFI may not be the right choice for every builder or mission but I'd happy to discuss that with you by email or phone.

You can watch some of our YT videos featuring Les Kearney's RV-10 to see how it all works:

https://www.youtube.com/watch?v=BUuUxkBq8EA&t=111s

https://www.youtube.com/watch?v=zEZqvhfutz4

https://www.youtube.com/watch?v=7YvXmq7vwzY&t=374s

Lots of other vids on our YT channel showing the components and how it's made, used in other aircraft.

Jeff at Thunderbolt is pretty familiar with component deletions if you decide to go with SDS and I can send you a short list as well.
 
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