Simple Injection Questions

Christopher J Beasley chris_beasley at mindspring.com
Fri May 21 17:42:39 GMT 1999



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





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