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This is where the main ignition programming of the system is done. For example, if you want timing at 20
degrees BTDC at 2500 RPM go to RPM IGNITION 2500 and enter 20. You should have knowledge of
what your particular engine needs for timing. Lycoming standard 360/540 usually 25 degrees max,
390/580 usually 20 degrees max. If your engine has higher compression and running MOGAS then
timing is usually less than the standard. Rotax typical timing is 26 degrees max. Again custom engines
may need different timing.
Lycoming new engine break-in: Limit timing to 18 deg for angle valve engines and 20 deg for parallel
valve engines. Adjust your RPM Fuel values accordingly! Dual ECU, don’t forget to program B ECU!
Detonation and Ignition timing:
The fuel/air mixture normally burns at a uniform rate within the combustion chamber however if the rate
of pressure or temperature rise becomes excessive, detonation can occur. This is the spontaneous
explosion of the remaining mixture sometime after the spark event occurs. The result is a rapid and
excessive pressure and temperature rise within the chamber, which can often lead to broken ring lands
on the piston. Having the ignition timing too far advanced for the fuel octane is the leading cause of
detonation, running the AFR too lean also contributes to detonation. You are not likely to be able to hear
detonation over the noise of the propeller and exhaust in an airplane so you must program the ECU so
that detonation cannot occur in the first place. Too much timing, high compression, and low octane fuel
can all contribute to detonation.
IGN RET-ADV/LOAD
This parameter allows programming of 64 points of ignition retard and advance with reference to load on
the engine. Load information is from the MAP sensor. RET refers to retard, and ADV refers to advance.
On systems using 1 bar MAP sensors all the IGN RET-ADV/LOAD values are set to zero from the
factory. Systems with 2 or 3 bar MAP sensors have some retard programmed in higher MAP ranges.
Adding retard in high ranges of IGN RET-ADV/LOAD will help prevent detonation on turbo or high
compression normally aspirated engines. Push the +10 or +1 buttons to increase the amount of ignition
retard. If too much retard is programmed, power output from the engine will be reduced significantly, and
detonation may still occur. Total ignition timing should not be less than 15 degrees, since this could
shorten the life of some engine components.
Advance can be programmed by pushing the -1 and -10 buttons on the programmer.
To program ignition timing, two parameters RPM IGN and IGN RET-ADV/LOAD are used.
Important- Total timing is a result of the RPM IGNITION value minus any RETARD or plus any
ADVANCE.
Values for IGN RET-ADV/LOAD are limited to a maximum 25 degrees advance, and a maximum 25
degrees retard.
LCD Brightness and Contrast
There are 8 settings for the LCD backlighting brightness, from 0 to 7. Use the +1/-1 buttons to increase
or decrease brightness for ambient cockpit lighting conditions.
There are 16 contrast levels available, from 0 to 15. This feature can help optimize viewing at different
viewing angles and also during temperature extremes. High temperature can affect the contrast so an
adjustment may be needed to compensate. Use the +1/-1 buttons to increment or decrement the setting.
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