New EFI

I am working on a new EFI system based partially I what I learned
using the TTC Motec
system.

It will be super easy to wire and super fast to wire. Can be wired
in minutes and not hours,.
This is a MAJOR breakthrough for after market EFI. Unlike all EFI
systems on the
market today.

There will be an EFIS built in with all the engine parameters and
manifold pressure.
All data will be recorded like the Motec.
It will be stored on a 32 Gig Micro SD card. This card can be taken
out and read by any PC
and most tablets and cell phones using Android. Maybe Apple but I
don't have
one to test it on. Not available on the Motec.

The screen on the instrument panel will be of your choice. All one
needs is a VGA
interface.

This is a list of the recorded and instrument panel displayed data
so far.

Manifold pressure
Oil pressure
Oil temperature
Water temperature.
Manifold air temperature.
RPM
Altitude. Handy for tuning.
Air speed
O2 rotor 1
O2 rotor 2
EGT rotor 1
EGT rotor 2.

It will control stock RX8 ignition coils. This saves money as you
will probably have them.
It will control stock RX8 yellow injectors. Dido.
It will use two a stock CAS. Dido for one.

It can handle two CAS as this is a critical part in all EFI systems.
If this goes out the engine stops. No if ands or buts.
So I have implemented two. One to control rotor 1 and one
to control rotor 2. If either one goes out notification is
shown on the cockpit screen and control reverts to the one
good one but but it will then control both rotors just like the stock
system.

More on this new EFI system later.

Paul Lamar

I can think of three other parameters that may be of interest:
Incoming air temperature
Throttle position
Timing relative to tdc
Also, how do you intend to detect an injector failure? I assume you
intend to incorporate the maximite in the design.
Good stuff.

Daniel Tyler

I see no real use for ambient air temperature as it affects the
mixture.
That is taken care of by manifold air temperature. Manifold
air temperature
is essential.

Throttle position will affect manifold pressure but it might
help in initial tuning.
Particularly in diagnostic mode.

Timing on a rotary, is 98% of the time, 22 degrees BTDC. Hardly
worth changing.
Assuming you start out running with good injectors the O2 will
change if
an injector fails.

I am doing my own PC board. Not using the Maximite.

Paul Lamar

If the injectors are sized for 45% duty cycle at full power, if one
fails the other can run at 90% without noticeable difference. In
aircraft this should not be much of a problem as idle could be on one
board and the engine runs at power levels 90% of the time.

Dale Davies

Right at the moment I don't know what the Mazda Yellow injectors
will do. I will make some measurements.

Paul Lamar

To get more out of Yellow RX8 injectors. (Run off one, 2nd as
backup / stagged)

http://injector-rehab.com/shop/RX8-and-WRX-Modification.html <http://injector-rehab.com/shop/RX8-and-WRX-Modification.html>

They will increase from 410cc/min to 820cc/min, and a cleaning too
/ system balance !

- Matt Boiteau

Thanks for the tip Matt.

Paul Lamar

Matt, do you know what dwell time megasquirt uses? Can it be adjusted?

My recent thinking on this is not use inductive coils at all such as the RX8 and the GM Ls4.
The M&W CD ignition on the TTC is working well. It does not require a computer to work.
Inductive coils get hot at high continuous RPM.

Paul Lamar

Yes of course the dwell can be adjusted. Pretty much any setting possible
can be adjusted. If not, the Megasquirt community is open source and they come up change.

You have 4 options of dwell type
* Standard Dwell - this is the setting to use for most installs.
* Fixed Duty - locks the spark output to a constant duty cycle instead of controlling dwell. e.g.
Ford's 'Push Start' TFI modules, Bosch 'smart' ignition modules, or MSD and other CD boxes.
* Time After Spark - only intended for Saab Tri-Ionic DI cassettes.
* Charge at trigger - rarely used. Could be used with MSD type CDI boxes when running Basic Trigger only."

Dwell vs RPM
Spark Trim - Enables the adjustment of timing per individual cylinder.
Cranking dwell - Specifies the base coil dwell time during cranking before battery correction is applied.

- Matt Boiteau

Do you program in "C" Matt?

Paul Lamar

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