http://www.megamanual.com/v22manual/rotary.htm#kurt

-----------------------------------------------------------------------------
"Ignition

Note: You may need to add a 50K Ohm resistor to the coil signal from the OEM ignition
to prevent rpm spikes, etc.

You have a few choices for ignition for a rotary engine:

    use a distributor from an older pre-'86 RX-7 to control ignition,
    use the stock ECU to control the ignition,
    use a MegaSquirt® derived ignition controller and non-stock modules (such as EDIS)
    use an aftermarket ignition controller.

Many different ignition solutions have been spawned from the base MegaSquirt® EFI
Controller, such as MSnS. The rotary engine ignition requirements, with trailing
firing after the leading, has not yet been achieved using MegaSquirt® or its
derivatives. Some users are running a modified version of MSnEDIS, which uses a
crank-mounted 36-1 wheel for timing, and fires four individual coils one per plug.
They usually have it configured to fire the leading and trailing plugs together with
zero split, and have noticed no complications in doing so. There may be issues when
running boosted engines in this configuration, although much conflicting information
exists on this topic.

Mike Robert spent some time on a dyno last year and was able to test what happened in
the case of stock 'spilt' spark timing, trailing only, leading and trailing firing
simultaneously (no split) timing and leading only timing.

The results were:

A:    Leading and trailing spark in a roughly stock timing split configuration gave
~164 RWHP @ 8500.

B:    Trailing spark only only ran very badly (as expected) and power was way down,
EGT was high enough to make the exhaust medium red; that run was aborted.

C:    Leading and trailing spark firing simultaneously were no different form stock
split until after 6500 rpm or so; even then the difference was almost negligible.

D:    Running leading only spark produced about the same power as well, within error
margins.

All of these tests were run with 26 degrees leading advance max on 87 octane pump gas.

However, idle and low load emissions might be better running both Leading & Trailing
spark with split timing."

-----------------------------------------------------------------------------------

This is good info and confirms what we have been doing along and that is firing both
plugs at the same time about 22 degree BTDC.

Paul Lamar

-- 
The Rotary Engine News Letter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net
You Tube key word PaulLamar2
Copyright 1998-2012 All world wide rights reserved.