<<The decreased fuel flow in cruise will cover their cost in about 300
hrs.>>

I would certainly like to see real data on this, for both single electronic
and dual electronic systems.  How much BSFC improvement is there to be had
by advancing only one of the sparks?  Both of the sparks?  I'm thinking of
manifold pressures of 20 inches or lower.  Has anyone done a real dyno test
to get this data?  How about a timing sweep under these conditions?

Gary,

 

Let's see, saving .66 gph for the same performance over 300 hours would use 200 gallons less fuel and, @ $3/gal that is a savings of merely $600.  Of course, if you used the gph savings to extend range you may save yourself a stop.  Gee, if you boost the fuel burn back to the previous level you will have increased the power - there is never too much power for a low-drag Lancair.

 

Take a look at the way Unison presented its' data for a fixed pitch prop on a carbureted C172 (I think).

 

 

Click on "LASAR Experience"

 

AVWEB wrote an article on LASAR and Part one has install info:

 

 

Part two has performance info:

 

 

Remember that this may be the worse performing electronic system, but with a comfortable backup - mags.

 

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Advancing one spark may be better than none, but the flame fronts start at different times - It is best to fire both plugs at the same time.  But, some people settle for 1/2 a system as it makes them comfortable with the apparent risk/reward.

 

No Dyno test is a replacement for a flight test.  Best is two planes side by side in a race.

 

What's a timing sweep?  Unison and E-Mag keep their timing secret, Lightspeed has an optional display so you can monitor the timing (change it if you dare, too).

 

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