Simple Injection Questions

[Hélène Villemure]

Bruce,

I wish you the very best through your stay in hospital. I was shocked to learn
that you needed such serious medical interventions! But Matti and I wish you a
quick and peaceful recovery.

Fare well,

Bruce Plecan a écrit:

> 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