There is bewildering amount of info and options in Megasquirt.  The relative
low cost ($250) and very simple early board known as the MS I V2.2 is still
available and will work on a rotary.  It does not have injector dampers but
you don't need injector dampers with Mazda high impedance injectors.  Also
it cannot stage the injectors.

Both sets of two injectors fire at the same time on each rotor. No staging
of the two injectors on any one rotor.  That means you will get the engine
to run well at medium and high RPM with a prop load but it may idle very
poorly as the dynamic range of most injectors is limited.  For example the
RX8 engine has 3 staged injectors on each rotor and Tracy uses 2 staged
injectors on each rotor.  The injection is not timed simply because a rotary
rotates too fast to time the injectors.

Also the software does not support timed injection. It is referred to as
"batch fire" and that is probably what Tracy is doing as well.  Timed
injection does not make much sense in a p-port rotary because the intake
port never closes.  That is unique to an intermittent class combustion
engine.  Yes the rotary is an intermittent class internal combustion engine.
Only turbo jet engines work that way and they are called continuous
combustion engines.

The ignition is not there so you must provide that. In fact it won't even
work unless you provide a tach signal of some sort.  You must use it with
one of several stand alone ignition systems that will work and that put out
a tach signal.  These are GM HEI, GM DIS, Ford EDIS, Ford TFI, Bosch 0 227
100 124 and MSD 6A.  IMHO the MSD6 is the best of the bunch but expensive.
All of these are documented.

No direct coil control (dwell) is available on MS 1 Version 2.2 and that
includes late LS1 and RX8 coils with built in high current switches.  Of
course there is no electronic way of leaning the engine from the cockpit.
You could rig a mechanical way of changing the pressure setting on the fuel
pressure regulator to affect leaning.

The documentation frankly is a mess with megasquirt. Basically what has
happened over the years is one kludge is piled on top of the last one as
they have added features.  There is a lot of redundancy in the html docs
(many web sites) so the whole mess of dozens of html files has become
extremely confusing.

The the top of the line hardware is also a mess with daughter cards and
adapters piled on the original MS II using the MC9S12 on daughter card
instead of the MC68HC908.  The whole mess is in dire need of separate USB
mother boards tailored to the needs of the customer.  Say 4, 6 and eight
cylinders.


A documentation trick I use is set up Word doc files on various subjects
such a USB and dwell among others and cut and paste the pertinent info from the many
redundant html files.

I aim to fix all this with a simple board specifically designed for the
rotary with just the features we need.  USB and RX8 or LS1 coil support (dwell) and
cockpit leaning.

Paul Lamar


You da man, Paul.

Van



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