A thought...

[Dan J. Declerck]

> 
> I'm thinking of putting fuel injection on my pontiac 455 in a '78 trans am.
> 
> I'd like to buy the 900cfm throttle body from holley that already includes:
> 1. 4 injectors, 85lb/hr (kinda like a tbi 4 barrel)
> 2. tps
> 
> All I'd need is an interface to these four injectors, a computer, couple of
> sensors (map, temp, ego, etc).
> 
> I'm thinking, instead of going the 68hc11 route, using a pc.  Instead of
> building a a/d and d/a board, use two parallel ports.  That would give me
> 8 ins and 8 outs.  Timing would be resolved by the computer, hell, 386/486
> motherboards are cheap.

Yes, but how will you mount it in your car? How much power can you afford 
to use to run this PC? The benefits might be swallowed by the additional
Horsepower lost in the new alternator required to run the thing.

You have to do things in Real-time, and no RTOS is easily accessable
for this system?

How will you isloate this computer system and it's connectors from vibration
inherent in automobiles?

How do you do the timing control without a TPU, and/or PWM waveform generator?

How do you get timing control tighter than 55 ms? (the timer tick on PC boards
are 1/18th of a second).

How do you program in 80386 assembler and have few bugs?


> 
> Question 1: Am I crazy? Anyone see an inherent flaw in all of this?
> 
> Question 2: I need a good power supply to give me +12,+5,-5,-12. Should I 
> pull the car's power, use a 12/24 volt transformer, then get a couple of
> voltage regulators to give the voltages I need? Car voltage lines are 
> extremely noisy, any ideas on how to clean the signal?
> 
> Question 3: Any suggestions, ideas, or people interested?
> 
> Arnaldo
> aec at ao.net
> 
> 


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=> Dan DeClerck                        | EMAIL: declrckd at cig.mot.com      <=
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