Paul,
Could you detail exactly what you want MS to do? If
that's clear, then a hardware/software config can be
specified to meet those needs:
Fuel Side:
# and type of injectors (low/high impedance)
Primary/secondary staging, or batch fire all four?
Ignition Side:
Stock 2nd gen ignition? If not, what coil/ignitor
type is to be used?
Leading/trailing timing split needed?
Sensors:
- Stock Mazda manifold air temp and coolant temp
thermistors? If not, what type?
- Stock CAS(Crank Angle Sensor), or custom
wheel/sensor? If custom, spec sensor type.
- TPS is optional, certainly not needed for testing
purposes. In MS world, it is used for accel
enrichment, and for triggering flood-clear mode.
Flood clear can be handled in other manners. Accel
enrichment can also be provided using map signal
(rate-of-change of map, rather than rate-of-change of
tps), which eliminates the need for TPS.
There are daughterboards being used by some rotary
guys to give a true 'plug-n-play' setup for use in 2nd
gen cars. Given your application, this can be avoided
completely.
If your spec is open, here's what I'd suggest:
Run stock high impedance injectors, or low impedance
with the stock resistor pack. This eliminates the
need for the extra flyback circuitry you may read
about.
Use a stock 2nd gen CAS, remove the upper 2-tooth
wheel and its VR sensor, and grind opposing teeth off
the lower 24-tooth wheel.
Buy an MS1 V3.0 based. MS1 indicates the HC908
processor, while V3.0 indicates board revision. The
V3.0 board has a number of improvements, one of which
is the integral VR (variable reluctance) sensor
conditioning circuit. This circuit will condition the
noisy AC signal coming VR sensor in the CAS, providing
a clean 0-5V signal from the modified CAS wheel.
Here's links to a couple reputable kit vendors.
Hopefully Yahoo doesn't mangle the links:
http://www.glensgarage.com/catalog/product_info.php?cPath=1&products_id=30
http://www.diyautotune.com/catalog/megasquirti-programmable-system-pcb30-unassembled-p-46.html
Use stock 2nd gen leading and trailing coilpacks for
ignition.
Once ready to run, drop me a line, or follow the links
from msefi.com for the latest stable release of
msnsextra code. This includes support for all the
features discussed above.
This will allow full ignition and fuel control, with
the minimum of fuss. Given your background, soldering
up a DB37 harness and wiring a relay or two will be
trivial, but the relay board might make the job a bit
easier.
Hope that helps a bit.
Roger.
All I need is something simple to work on the dyno.
Turbo charged 2nd gen engine. Ignition is not mandatory as
I can lash something up that will fire both plugs 20 dgrees
BTDC. I can go with the CAS or build an RX8 style
trigger wheel and pickup. I am using stock 2nd gen injectors.
I ordered the bare boards from DIY.
Is msnsextra code C or 68HC908 asm source?
BTW I am thinking two of these could be used in an airplane
with a 37 pin plug on the instrument panel. Unplug one and
plug in the other as a preflight backup check. They are cheap.
Paul Lamar ...No rotor no motor.
I believe the msnsextra is all assembler and the MS-II stuff
is written in C.
Roger is a big MS contributor, and I owe him a beer or two...
Cheers
Cary
Yes I think I read that somewhere. I like to work
in asm when I am doing real time stuff. Actually I don't
like C at all. I took a course in it one time and
I thought it was dumb :) In asm there is a one to one with
the hardware. Very mechanical :)
Paul Lamar ...No rotor no motor.
The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site.
http://www.rotaryeng.net
Copyright 1998-2006 All world wide rights reserved.