SDS electronic ignition
Something that looks like a well thought out product from Canadian company http://sdsefi.com/aircraft.html
Installation discussion and real life fuel economy figures on http://www.vansairforce.com/community/showthread.php?t=132220
Interesting. It looks like 6% more MPG.
I would want that checked on several engines because this will depend on which bit of the cruise regime you are operating in. Electronic ignition should be extra good for the LOP bit for example.
Also I see somebody installed two of them, on an IO540, so two separate systems. How are they powered?
Not sure I like this bit
“This ECU is not waterproof and will not function as designed if moisture invades the enclosure or power/ ground connections are interrupted. Failure of this unit may result in a complete loss of engine power.”
Looking at the connectors they use, this is right out of the Vauxhall Viva era
I do like their product for trimming fuel flow to individual cylinders.
The MPG gets better when LOP on dual EFI:
Now flying the dual CPI system. Had to wait a few days for the 50 MPH winds to die down but got a quick flight in this evening. Mag drop is minimal (~30RPM) on either system compared to the 125 on the mags. Climb was strong all the way to altitude (it is fun being able to maintain 3,000 FPM climb as you pass through 9,000 feet!) and going way LOP (9.7 GPH) still delivered 185 KTAS. BTW, that was my “old” cruise numbers at 11.5GPH So it looks like I picked up my expected 1.5 GPH with the switch to full electronic ignition. And yes, the “LOP” switch gave a noticable boost when this lean.
Peter wrote:
How are they powered
12v from the ship batteries. The system draws 1.5A at full load so with a small “emergency” battery you could fly for hours even in case of alternator failure.
Very impressive.
Is my understanding correct if I say that it gets timing from a sensor in the flywheel, RPM from same, and with the addition of MP it computes the ignition timing based on a predefined curve? And on top of that the pilot can provide additional timing offset?
I saw one of these planes was fitted with a LOP switch .What does that do? Further timing advance to adjust for slower burning fuel?
Correct. The LOP switch changes advance from high power (eg 22/25) to LOP cruise (33/37).
If you get the fuel injection part (pumps / injectors / computer) you can individually trim AFR at each cylinder.
I get the moisture concern, but if you get that much moisture in the cockpit for it to “invade the enclosure” you’ve probably just ditched :-)
Shorrick_Mk2 wrote:
I get the moisture concern, but if you get that much moisture in the cockpit for it to “invade the enclosure” you’ve probably just ditched :-)
Surely the ECU is not in the cockpit but forward of the firewall?
All the electronics are in the tiny box in the cockpit. Only the coil pack and the sensors are forward of the firewall.
It’s electronic fuel injection. (+ some ignition, if you want).
Actually it is the other way around – electronic ignition plus EFI if you want. The builders state that EFI does not improve much on the base Continental architecture (especially the 550) as it is better designed than the Lycoming one.
