Simple Injection Questions

[Bruce Plecan]

Gee, maybe Holley has something in the works <wink><wink>
I hadn't heard about their Cutler tie......
Doc


| EFI Trivia FWIW
| Cutler (who won one of the early magazine EFI Shootouts) was bought by Hi
| Rel a year or two ago.
| Hi Rel was bought by Holley within the last year.
| When I bought my Cutler manifold, they were only making stuff for boats.
| I was told that the self learn capability required a lot of time at each
| specific load condition and boats were closer to that than cars.  Cars
with
| a duty cycle of start, accelerate, shift. shift, shift, backoff stop, etc.
| didn't provide a chance for the system to learn and I was told that a
later
| version of the system would again address cars - I dont think it ever
| happened before Cutler was sold.
| Thats why I'm blending a 7727 with my Cutler and other PFI parts.
| Bud
| >From: "Bruce Plecan" <nacelp at bright.net>
| >Subject: Re: Simple Injection Questions
| >Alpha-N  means the EFI just uses Throttle Posistion, and rpm to figure
fuel
| >and/or timing.
| >  PE  is Power enrichment.
| >  Self tuning is a dream for really high performance.  There is no way to
| >optimize tuning other than by testing.  Self compensating for slight
| >changes, maybe..  If you change the volumetic effeciency, the you'll have
to
| >test to find best Air Fuel Ratio, and to be best, would also, be
optimizing
| >timing.
| >  "Self-Tunig", is a buzz word.  Compensating does exist in the world as
we
| >know it.
| >  Self Tuning was done by the Cutler EFI Co., in FL.  But, they are out
of
| >business as far as I know.  The problem was loading the engine down long
| >enough at one time for the computer to learn things.   Talked with a guy
who
| >had done several of the installations, and after 4, he was finished
trying.
| >Took many hours on dyno, and 2 applications were boats.  Not enough
waterway
| >for unlimited WOT testing.
| >  Single cylinder closed loop might be a real challenge.  The time from
| >cycle to cycle is so long..  To get any averages you'd be using waiting
days
| >for when to apply the correction, unless you go event by event and at low
| >rpm you might wind up with stalling before an odd event is averaged out.
| >Singles can be very erratic at idle, from what Cub work i did years ago.
| >  A basic Alpha-N, with barometric, and Intake air Temp compensation
would
| >be about as sweet and complex as I'd think would be practicle.
| >  Probably best to use a "fixed" pullse at idle (other than for the above
| >corrections), and some pots for accleration, transistion (accleration,
and
| >decleration), and WOT tuning.
| >  Might use a WB O2 for just seeing where you are, rather than close
looping
| >it.
| >Just my 02 cents
| >Grumpy
| >| > I think a single cylinder engine will have a very discontinuous air
flow
| >| > which effectively eliminates MAP and MAF.  The simplest system I can
| >think
| >| > of is alpha-n, rpm and throttle position.  It can be mapped to a
lookup
| >| Ok, MAP/MAF = manifold air pressure/flow right?What's alpha-n?
| >| > table and then corrected for temperature and exhaust O2.  But why do
you
| >| > insist on closed loop?  As far as I know, that is most useful for
making
| >a 3
| >| > way cat work.  Without a cat, you actually want a lean cruise and
rich
| >PE.
| >| > Neither of which are well indicated with a normal O2 sensor.
| >| What's PE?  The reason I want some sort of closed loop is that in bike
| >| applications, people are always changing things like different exhaust,
| >air
| >| filters, modified airbox, etc.  I want the injection system to
compensate
| >and
| >| I've been instructed that MAF with O2 will compensate for modifications
| >like
| >| this.
| >| > To answer your second question, no, you don't need to include
ignition
| >| > timing although there are advantages associated with electronic spark
| >| > timing.
| >| Well, most bikes already have CDI now so it might be pretty easy to
take
| >over
| >| triggering.  What are the advantages/disadvantages?
| >| Thanks!
| >| Beez