MAP sensing for IR systems

[mike mager]

MysticZ replied:

>Mike Mager wrote:

> > Bruce, Bernd,
> > thanks for the suggestions.  I was hoping that there was a way to avoid 
>commoning the MAP source.  I did leave out the aspect of the fuel-pressure 
>regulator reference source - very silly of me.

>So use individual MAP sensors . . .

I had 'brain-stormed' that (expensive!);  there are no wrong answer in a 
brainstorming session - that's what they are for! - but very few practical 
ones (hey, we only need one good one!).

>. . . but have a 2nd port in each runner for the fuel pressure. Or just 
>hook the FPR to a single runner since it's likely to be close enough to the 
>rest of them for a "low-tech" FPR anyway.

As the others have mentioned, there would be a whole lotta pulsation, 
compared to Detroit's using a MAP sensor at a large plenum; a regular 
diaphragm type of regulator would _try_ to follow the pulsation (and would 
run outa bandwidth!), but we dunna want to follow _one_ cylinder's 
pulsations (remember, I admitted to spacing-out the fuel-pressure issue - no 
parts bought/cut yet!); with the proposed me-built custom ECU, the discrete, 
per-cylindr, MAPs could be processed to figure the desired fuel-pressure;  
I'm sure that there is a way to regulate with computer control (it is only 
more money).

>The system I'm working on treats each cylinder as it's own engine, but I 
>only have 2 cylinders to deal with and no need for any vacuum/MAP reference 
>of any kind. Not the most precise way of controlling fuel, but it's close 
>enough. With an engine that can see 5000 rpm and 11000 rpm in under a 
>second there's more important things to worry about ;)

Is that for your EX?  I got the whole idea for a me-built ECU from an 
article in Circuit Cellar by a guy (reading this list?) that built one for a 
Formula SAE racer (four-cylinder MC engine).

>MAP and MAF just aren't fast enough.

Wow!, that's a consideration.  What do you expect about 'speed' problems?;  
that Formula SAE used speed/density IIRC;  are you thinking to go alpha-N?  
(Got to find that Formula SAE article again!)

>Closed loop and loopup tables based on RPM and TPS will handle it if the 
>processor is fast enough.

Did you mean open-loop? (Not arguing, just trying to follow!)

>Now to worry about that fuel atomization issue...

Huh? What?  Atomization is very important, definitely, but I wonder . . . 
the new bikes do use EFI successfully, as does Formula One (which I know 
little about except up to over 17,500 RPM, and the pretty pictures in the 
books).

Here I spill it to the list, I have a deep, dark, secret inside of me - I 
want to modify a Ninja engine, and a custom EFI is a part of it.

Thanks, Steve,
Mike

>--
>Steve
>97 Chevy Camaro Z28, Mystic teal, A4, not stock
>90 Kawasaki EX500A4, black, M6, not even CLOSE to stock!
>lt1_z28 at ev1.net  http://users.ev1.net/~lt1_z28
>Aluminum, steel, carbon fiber, titanium, and two cast iron balls.
>McMillan Motorsports- http://www.mmsbikes.com
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