KISS EFI

[rr]

Someplace in here is a statement about redundency. Even with
todays EFI, it can be as simple as a spare ecm waiting in the trunk.

Unlike XA, 'we' can pull over if need be <fortunately>.

BobR.

Garfield Willis wrote:

> On Fri, 30 Jun 2000 22:29:45 -0700, garwillis at msn.com (Garfield Willis)
> wrote:
>
> >Sure, but there's "reliable cuz it's simple" and there's "reliable cuz
> >it's failsoft/failsafe". In XA we're not much a fan of the "simpleton".
> >It's just amazing how "un-simple" that "simple" system can be. :)  When
> >your life's on the line, you want backup, not "simple" solutions.
>
> Geez, I must be losin the paltry remnants of what's left of me mind!
> Actually, we ARE all fans of what's simple, aren't we? FIRST and
> foremost, you want "reliable cuz it's simple", THEN when it's really
> critical, you ALSO want "reliable cuz it's failsoft/failsafe". Not good
> to pit the two agin each other; it ain't either/or. And maybe another
> point is, you don't wanna substitute redundancy for the additional
> reliability that simplicity can give ya. But when all is saidNdone, and
> the pucker meter pegs, there's nothing quite like a backup. That was my
> point.
>
> What I said about the sposedly "simple" system turning out not to be, is
> true enough, but that dudnt negate the fact that there IS "simpler" vrs
> "more complex". Didn't mean to sound like I was saying, "nothing's
> simple, so all you can do to enhance reliability is make it redundant."
> Twasn't me intent, tho it sure mighta sounded like it.
>
> >>BTW, I have this conceptual problem with redundancy and reliability.
> >>Seems to me that the more redundancy is built in, the more inherently
> >>unreliable the system will be. But that topic alone is a whole new
> >>can-o-worms.
> >
> >Nah, no can-o-worms, just a matter of training and technical education.
> >You heard o'the Space Shuttle haven't ya? Yeah, they got tripple
> >redundant systems on-board. They did that cus they wanted the
> >"inherently unreliable" systems you contemplate.
> >
> >Go fish, Peetie.
>
> Ya know, I answered the way I did cuz I thot the intial retort was a
> troll. Probly was. But in re-reading it, I realized that regardless of
> where the comment is coming from, there's an altogether toooo common
> misconception at work here.
>
> Redundancy and simplicity have NOTHING to do with each other.
> Reliability and simplicity DO. You can have a system that's just DIRT
> simple, and then if you have TWO of them, you're still better off
> (unless you do something really dumb). It's called "spare parts", eh?
> There are two basic types of redundancy: passive and active. Passive is
> where, when you believe you have a failure, you shut one down (or toss
> one out, your choice of words) and swap another one in. "Spare parts",
> sotaspeak. Active redundancy is where you have multiple "good ones"
> running/working in parallel, and they all vote to throw the joker out if
> someone runs amuck, and there's a disagreement about who's sane and
> who's not. That's what Greg was referring to in the Shuttle.
>
> What's all this gotta do with EFI? Wull, I find the complexity of modern
> ECUs pretty overwhelming, but given all the smog requirements, I'm not
> at all sure how to avoid it. OTOH, it's sure awful easy to miss the
> forest for the trees. It IS really true what they say about "at some
> level of complexity, technology is indistinguishable from magic". When
> things get so friggin tangled that you have to be a member of the EFI
> illuminati for years before it all comes together in your mind, geez
> something's baroque (as in "broke").
>
> I guess that's why I think KISS EFI also has a place even in the
> automotive scheme of things, if for no other reason than to bring us
> back to the roots of the thang. Probly would surprise alot of us to see
> that you can actually implement a perfectly *driveable*  and
> well-performing EFI with just a few chicklet parts. Well, it probably
> wouldn't "theoretically" surprise us; we're all too smart and educated
> for that, eh? But regardless of the General's Bogus Adventure contest,
> it does seem like going back to basics does have it's attractions.
>
> A lot get's lost in the translation of learning. For the sake of
> understanding the basics and the subsequent frosting layers, anyone ever
> disabled ALL transient (and static/temp-dependant) enrichments in their
> ECU, and "felt" how the engine ran/vehicle performed? Criminee, ever
> since the idle mix limits imposed on carbs when smog req's hit hard, a
> person could grow up these days without knowing what rich stumble &
> fouling or lean lope & misfire even FELT like! NOW, on the EFI cars,
> there AIN'T even any idle mixture screw! Hee hee. Geez, there isn't even
> any idle speed screw anymore! See my point? What's the world coming too?
> :)
>
> There just seems like there's gotta be something valuable, let alone
> attractive for fun's sake, to starting out with some injectors, a
> throttle body, and the worlds most primitive FI controller, and build up
> the layers one by one. First you start with straight-line fueling MAP-n
> say. NO transient enrichments, no TPS-based tip-ins. Do the same with
> IGN/timing. Start with FIXED or manual advance (seriously; it used to be
> that way in the old...really old...days). Measure AFRs out the tailpipe
> to see how much variation you get over rpm & load (you knew there was
> gonna be some reason you had to have an AFR meter, didn't ya? :) But
> most of all, see how it FEELS. Do the same with Alpha-n fueling, using
> just TPS and rpm alone; how many of us have ever driven an n-alpha
> fuel-injected vehicle and know how they feel to drive? Let alone watched
> what the mixture was doing (wow).
>
> So much for the ramble. I guess I'm just feeling old and fossilish, and
> wondering if we're not missing some valuable lessons by "growing up too
> fast", EFI-wise.
>
> Gar
>

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