KISS EFI

Garfield Willis garwillis at msn.com
Sat Jul 1 02:04:15 GMT 2000


On Sat, 01 Jul 2000 10:33:59 +1000, Peter Gargano
<peter at techedge.com.au> wrote:

>Garfield, do you have any URLs for KEFI (KISS EFI), or an archive etc.?

Hey, Peetie.

We have a site that's "member's only" (don't ask), but I could pull some
of the .jpg's over into the public area for perusal, if after all this,
you're still interested.

Lemme tell ya some of the particulars, before you get all hotNbothered,
tho.

First of all, in XA we aim for REDUNDANCY, so the pixs show a totally
redundant/dual DIS system, where the entire IGN system continues on
totally unharmed, even after *any* single point of failure (pickup,
module, coil, HV wire, etc.). That creates a true rats-nest of HV IGN
interconnect (especially on 6-cyl DIS; whew!). You can look at that, but
it's not pretty, and unless you're dealing with 48hr road races with big
purses, I'd expect you'd "hurl" at the looks of it, and pass. Oddly
enough, it's NOT all that spendy in terms of weight overhead, but it's
truly fug-ugly in terms of all the HV IGN wire routing.

Second thing is that in our KEFI setup, we DON'T have any throttle
transients to deal with, so it would NOT be suitable for automotive.
IOW, you'd instantly lean-stall the first time you stuffed your foot in
it, in an auto. Thankfully, in aircraft the throttle isn't a "pedal".
That's why I was encouraging a "smithsonian" of that Caddy (or D-jet,
whatever) system, just to hopefully show the very minimalist
requirements FOR AUTOMOTIVE, which HAS to include such things.

Now, that doesn't mean something *much* more simplified couldn't be
worked out for pump shots and general PE, but we haven't had to deal
with any of that, since XA engines are pretty much like "stationary
engines", in that they run at high power levels fairly continuously, and
have relatively gradual throttle changes.

Finally, there's the whole issue of IGN timing. Since XA engines run at
>50% power ALWAYS, except when idling, we have NO use for light
part-throttle issues that would make vacuum advance a vital economy
feature otherwise (namely, in automotive). So we toss such things from
the getgo. This essentially allows us to disconnect the FI from the IGN,
since we don't need the ECU to monitor MAP for us to determine optimum
spark advance. It's now mostly a function of rpm alone (remember
centrifugal advance?), so the IGN and FI sections can operate completely
independantly.

Are you jealous yet? I know this must seem a totally "paradisiacal"
dream to automotive guys, but it's true in XA. We have NO emissions
requirements, no transient or "driveability" crapola requirements, just
TWO issues and TWO regimes: (1) make *max raw power* at Take Off/Landing
(in the event of an abort or go-around); this is referred to as the
"TOL" regime, and (2) make "max *economy*" whilst cruising at altitude,
which is a lackadaisical regime where the pilot has lotsOtime to
manually tweak the mixture, EGT, power, rpm, thrust, MAP to his heart's
content, to get things peaked at minimum fuel burn for maximum airspeed.

BOTH regimes are at such optimum/opposite poles of the spectrum, that it
makes for some very nice simplifications.

Ahhh, I could go on, about why XA is an engine experimentor's paradise,
but I forebear. :)

Gar


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