ECM and Methanol & Gasoline (was Re: Phase Seperation)

[Frederic Breitwieser]

>I also want to run on Methonal, at least under boost conditions.
>So does this mean there are special-purpose electronic injectors
>for methonal?  

There very well might be - my pals and I are kinda of the junkyard sort :)

>My opinion/idea is why not use a common Intel x86 motherboard
>for an ECU?  Then one could build specialized plug-in ISA cards.
>Sure they are overkill for a mass-produced car.

Very true, however there are advantages and disadvantages of a PC based
system.  First, I'd highly recommend the PC104 standard (www.pc104.com)
since its a much smaller footprint, and utilizes +5V only, rather than
requiring a -5/-12 power supply.  Great for automotive applications.  In
fact, I'm venturing into this myself.

Pros: 
   Uses common compilers (djgpp, Borland C/Pascal, MS Visual anything, etc)
   No real need to make circuit boards (PC104 manufactures have A/D as well
as server/stepper controllers
   Reasonably priced for one-off applications (considering cost of making
circuit boards, time involved, etc)
Cons:
   Longer boot times.  PC's have to count memory, check disks, etc.  You'd
have to hack into the BIOS to eliminate this.  Most embedded systems when
you turn the key to "on", the ECU is running before the key reaches "start".
   Higher power draw.  Multiple PC boards (in the 104 standard) can arrive
at a few amps pretty easily.  A dedicated embedded controller, because of
the simplicity and purpose-specific design, can use very little power (I'm
excluding the injector drivers in both cases of course)

>Sorry if this has all been discussed before, I'm working through
>the archives now..

I haven't seen it myself.  However, in the archives, there are instructions
for running a 4.77Mhz PC system board as an EFI system for a Pontiac 6000
(I think)... I downloaded the code a few months ago, written in basic, and
was poking around.  The author had done a nice job with it.


Frederic Breitwieser
Bridgeport, CT 06606

Homebrew Automotive Website:
http://www.xephic.dynip.com/

1993 Supercharged Lincoln Continental
1989 HMMWV
2000 Buick-Powered Mid-Engined Sports Car