PC based engine management system

JMACKENZ at uk.ibm.com JMACKENZ at uk.ibm.com
Tue Aug 10 10:32:09 GMT 1999

Hi, I'm new to the digest and have joined because I've set myself a long
term project to design and build a road legal drag car (ie nothing too
stupid or expensive) for which the engine is fully managed from a laptop
computer. I'm doing this mainly as a challenge for fun and will share all
my results / code etc when I have anything worthwhile. I've never attempted
anything like this before and any cars which I have built previously have
always used carbs rather than EFI but I will put the effort in to make sure
I succeed. My knowledge of the workings of common engine management systems
is very limited and this is the first area which I need to learn about.
Does anyone have a good document or website which describes basics /
details of the engine management system including the fuel maps? I'm also
looking for a description of the what is sensed from the engine (ie airflow
/ MAP / oil / water temperature / crank position  etc) and what effect this
has on the fuel delivery volume / timing  and the ignition timing? Also I
need to figure out or buy an input / output device for the laptop (PCMCIA /
Parallel / RS232 ?) which will allow me to sample all the inputs and output
to fuel injectors etc. Any advice on this would be most appreciated!

What I'm looking to achieve initially is to have an engine (very probably a
Rover V8 from a 1984 Rovertec Vitesse) for which the fuel delivery is
managed via a hardware interface to a laptop which runs custom written
software. I would then like to add in the ignition timing then a
supercharger or Janspeed twin turbo setup (or both). Eventually my goal
would be to include servo throttle control and other stuff to basically
allow the car to drag a 1/4 mile based on an optimised program without any
driver intervention except for steering!

I know this is a huge never-ending project but it'll keep me entertained
for a long while and it'll be worth it in the long term. I know I'll
destroy numerous engine parts. I'm lucky that I have a lot of technical
support and enthusiasm from friends. I'm aware that the first year will be
spent in the garage but this is no different to most of my projects! In
addition to standard tools, the equipment I have (or have access to)
includes the following;

Emmisions meter
Numerous volt / current etc meters
Digital oscilloscope
EEPROM programmer

My background - I'm a degree qualified Electronic / Mechanical engineer
with a great interest in cars. I work in IBM as a senior WW test engineer
for Thinkpad (Laptops) manufacturing which means that I can program in C /
Turbo Pascal and Rexx and have a pretty good understanding of computers.
Working in IBM also gives me access to the skills required for ciircuit
design etc which I'm a bit rusty on myself. I will be working closely with
a friend who has a lot of experience with building strange cars and engines
but he also has little knowledge of EFI systems.

If anyone can offer me any initial (and hopefully ongoing) help and support
then I would be most appreciative. I am a complete novice in this field
just now but I'm a fast learner if I get the help I need.

Best Regards
James MacKenzie

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