MicroSquirt.com read only forum (Jan.15,2018)

G'Day andy,

I only know of one or two people who have MAF "kind of" working on
motorcycles (z650 and up in capacity). Alpha-N seems to be the way to
go or perhaps a hybrid control might be better if it was available.

Sid



On 11/23/05, the bubbler <melodic.wave@btinternet.com> wrote:
>
>
> What are you guys planning to use for fuel control- Alpha N?
>
> Reading some posts on the forum, it seems a single cylinder engine doesn't
> produce a useable pressure for MAP, so it either Alpha N or possibly MAF?
>
> Seems like there are plenty of success stories with larger multi cylinder
> engines, but not much for small singles. Guess it's a niche interest.
>
> Andy
>
>
>
> This post is at:
> http://www.msefi.com/viewtopic.php?p=86181#86181
>
>
Posted by email.

In the posts I've searched, you can mix Alpha-N with MAP, so perhaps that is the way to go.

Can anyone explain why MAP doesn't work well on a single?

Andy

The unfiltered Map signal on a single or even a twin has large fluctuations that make it difficult to consistently generate a "clean" number for the software to make enrichment and VE table decisions on. People have successfully filtered and smoothed the signal by both mechanical and/or programmatic means. It all depends on the application and how much the load is going to vary as well as how radical the cam or port timing is, intake and exhaust tract reversions, etc. Many variables!

-Mike

Just a few thought that may help but I was going to try placing a Capacitor & Resistor on the signal pin of the MAP sensor to try to smooth these fluctuations out, in conjunction with an orifice in the Vac line. Adjusting the size of the orifice as well as moving the orifice up or down stream from the MAP sensor in order to dampen this further perhaps.

Bentrods

Well the cam timing on the Isetta engine is very tame, even by 1950's standards-208 degree overlap.

I thought it would be the pulsing that may throw the CPU, thanks for confirming that.

Anyone know of some good links of folks who have successfully converted singles?

Andy

Hello Andy,
if you plan to convert an older engine (Isetta) maybe some pics help you how I installed injectors and other EFI hardware.
http://megasquirt-de.serviceline.ch/suc ... ll0001.htm
Sorry, German only, but some pics - click to enlarge.
Overview: http://megasquirt-de.serviceline.ch/suc ... ex0001.htm

I use a carburator fuel filter to smooth MAP signal, but isn't dramatically - I like BentRods idea of cap&res! Definitely I'll ask a friend who's familar with such components! Another idea would be to use an old EFI fuel fine filter (more restriction, bigger capacity --> integral)
»Horst