Simple Injection Questions

[steve ravet]

Christopher J Beasley wrote:
> 
> 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?

Alpha-N is the simplest FI possible using only throttle position (alpha)
and engine RPM (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.

PE=power enrich, more fuel when you stomp the pedal, er, twist the
handle.

--steve

> 
> >
> >
> > 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

-- 
Steve Ravet
steve.ravet at arm.com
Advanced Risc Machines, Inc.
www.arm.com