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Setting up Lightspeed Ignition without advance.

Has anyone set up their Lightspeed for a fixed timing?

If so, how did you do it?

You'll need to call Klaus Savier and ask if this is possible. You can disconnect the Manifold Pressure line that limits restricts the timing to RPM advance, but that advance curve is hard coded into the LSE box.

Be prepared for an "argument" from Klaus; you'd better have a really good reason that makes sense to him.
 
Might be interesting to know why gasman would want to detune an EI to fixed timing. To match a mag?

I know of only one (2 actually) EI offerings that could be programmed like this. The SDS CPi and CPi2 electronic ignition kits are totally programable. Would take 5 minutes to change to what ever fixed timing you want. Would take 7 minutes to re-program it to what ever advance curve you desire.
 
Might be interesting to know why gasman would want to detune an EI to fixed timing. To match a mag?

I know of only one (2 actually) EI offerings that could be programmed like this. The SDS CPi and CPi2 electronic ignition kits are totally programable. Would take 5 minutes to change to what ever fixed timing you want. Would take 7 minutes to re-program it to what ever advance curve you desire.

The six cylinder pMag (200 series) can be programmed to do this as well (why anyone would want to is another topic). Programming this pMag is simple, and done during installation. Changing it at any point is also straight forward.

Carl
 
Might be interesting to know why gasman would want to detune an EI to fixed timing. To match a mag?

I know of only one (2 actually) EI offerings that could be programmed like this. The SDS CPi and CPi2 electronic ignition kits are totally programable.

Add Surefly and EDIS/Megajolt to your list.

Surefly offers multiple preset fixed timing choices. Megajolt can be set to almost anything desired, with dual maps. I keep one fixed and one variable in memory.

The six cylinder pMag (200 series) can be programmed to do this as well (why anyone would want to is another topic).

There are reasons. Not all this serious, but...

https://vansairforce.net/community/showthread.php?t=201345
 
Agree Dan - but for the vast majority of builders gaining engine efficiency in cruise would override building fire breathing “time to climb” RVs.

For those running such high compression engines I suggest careful thought be given to imposing POH limits on engine MP, retard timing, or both. My “around the world” Lancair IV neighbor restricts MP on takeoff for his 10-1 Continental 550 engine running dual electronic ignitions (a couple of degrees retarded on base timing and ~9 degrees max advance). The timing is at base for takeoff. He needs both the high compression and timing advance to gain fuel economy (38 hours on a tank of gas). The restricted take off MP and selected base timing (no advance for takeoff) helps mitigate detonation risk. He just rolled 2000 hours on this engine - only one jug had to be replaced.

Carl
 
Agree Dan - but for the vast majority of builders gaining engine efficiency in cruise would override building fire breathing “time to climb” RVs.

From Nigel Speedy, one of our professional test pilots...and remember, this was for a parallel valve with higher than stock CR.

Efficiency
An advertised advantage of electronic ignition is that the high-energy spark, in conjunction with variable and more highly optimized timing, results in “substantial” increases in efficiency. A quick internet search yields claims on the order of 10–15%. We normally think of efficiency as specific range, measured in units of nm/gal, which is the same as TAS/fuel flow (nm per hour/gal per hour). In my experiment, the fuel flow was constant for each test run. The ignition advance that resulted in the highest speed also resulted in the highest specific range. When the specific range was compared with the specific range achieved at 25 degrees ignition timing (baseline for my engine), it was possible to isolate the improvement in efficiency due to optimized timing alone. When ROP, the average improvement in efficiency due to optimized timing was 1%. When LOP, the improvement in efficiency was slightly higher, averaging 4.3%. The greatest improvement I saw was only 5.9%, which shows that ignition timing is not a significant factor in increased economy. Efficiency was improved more by simply climbing 4000 feet than optimizing the timing at any given altitude. Repeating this test keeping TAS constant (by adjusting throttle) and measuring fuel flow versus timing advance had the same outcome.
 
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