[Diy_efi] Fixed frequency PWM batch mode FI

[Ron Schroeder]

Hi Les,

Since torque is roughly proportional to fuel injected per combustion event
and air is roughly proportional to MAP, the simplest first order fuel
calculation is MAP times RPM.  So having injection NOT related to RPM would
actually make fuel calculations harder.  My first EFI was as simple as a 555
triggered by the ignition and the MAP scaled and inputed into the threshold
pin.

Ron Schroeder
WD8CDH
day 631 344-4561
nite 631 286-5677

----- Original Message -----
From: "Les Dittert" <lesd at earthlink.net>
To: <diy_efi at diy-efi.org>
Sent: Monday, August 19, 2002 8:42 PM
Subject: [Diy_efi] Fixed frequency PWM batch mode FI


> I have searched high and low and haven't found the answer to this
> question:
> are there any disadvantages to running the injectors at a
> fixed frequency of injection that isn't related to RPM?
> I realize that doing this in batch mode will result in some injections
> hitting a close valve sometimes and then sometimes hitting an open
> valve.
> Since some OEM fuel systems run batch mode where they fire all injectors
> at the same time
> I figured they have the same situation anyway.
> Another question:
> If using a fixed frequency you what should that frequency be?
> I'm assuming it should be something equivalent to running a sequential
> injection system at about 4000 RPM.
>
> -Les
>
>
>
>
>
>
> _______________________________________________
> Diy_efi mailing list
> Diy_efi at diy-efi.org
> http://www.diy-efi.org/mailman/listinfo/diy_efi

_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi