Simple Injection Questions

[Fran and Bud]

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
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>From: "Bruce Plecan" <nacelp at bright.net>
>To: <diy_efi at efi332.eng.ohio-state.edu>
>Subject: Re: Simple Injection Questions
>Date: Fri, May 21, 1999, 11:11 AM
>

>
>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
>
>