Simple Injection Questions

[Chew, Aaron]

I have no 1st hand experience.  I've read that it is tricky and that the
initial throttle opening doesn't provide good resolution, i.e., small
throttle changes produce big engine load changes.

A know of a BMW M3 person who converted from a vane flap meter to alpha-N
who was pleased after a lot of tweaking and solving idle issues.

I'm thinking about converting to alpha-N for my next project.

Aaron



-----Original Message-----
From: Christopher J Beasley [mailto:chris_beasley at mindspring.com]
Sent: Friday, May 21, 1999 10:09 PM
To: 	
Subject: Re: Simple Injection Questions


So you can actually do OK just with those two things?  Would it be as good
as or
better than a carb?
b


Chew, Aaron wrote:

> Alpha-n is a throttle-position and rpm fuel map control strategy.
>
> -----Original Message-----
> From: Christopher J Beasley [mailto:chris_beasley at mindspring.com]
> Sent: Friday, May 21, 1999 1:43 PM
> To: diy_efi at efi332.eng.ohio-state.edu
> Subject: Re: Simple Injection Questions
>
> Gary Derian wrote:
>
> > 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